@article{wang_vahabi_taassob_pillai_kota_2024, title={On-Demand, Contact-Less and Loss-Less Droplet Manipulation via Contact Electrification}, ISSN={["2198-3844"]}, DOI={10.1002/advs.202308101}, abstractNote={Abstract}, journal={ADVANCED SCIENCE}, author={Wang, Wei and Vahabi, Hamed and Taassob, Arsalan and Pillai, Sreekiran and Kota, Arun Kumar}, year={2024}, month={Jan} }
 @article{ding_vallabhuneni_liu_wang_zhao_wang_tang_wang_zhang_kota_et al._2023, title={Eu<SUP>3+</SUP> Complex-Based Superhydrophobic Fluorescence Sensor for Cr(VI) Detection in Water}, volume={13}, ISSN={["2079-4991"]}, DOI={10.3390/nano13182574}, abstractNote={Cr(VI) compounds are bioaccumulative and highly toxic pollutants, and there is a need for simple and fast detection methods to monitor their trace levels. In this work, we developed a Eu3+ complex-based fluorescence sensor to easily detect Cr(VI) in water droplets. Our sensor consists of a nanofibrous membrane electrospun with a blend of polyvinylidene fluoride (PVDF), silica particles, and Eu3+ complex. Upon modifying the membrane surface with fluoroalkyl chemistry, the sensor displayed superhydrophobicity. When a water droplet with Cr(VI) was placed on such a superhydrophobic fluorescence sensor, the overlapping absorption of Cr(VI) and Eu3+ complex facilitated the inner filter effect, allowing the selective detection of Cr(VI) down to 0.44 µM (i.e., 45.76 µg L−1). We proposed and designed of new inexpensive and fast sensor for the detection of Cr(VI).}, number={18}, journal={NANOMATERIALS}, author={Ding, Wei and Vallabhuneni, Sravanthi and Liu, Jin and Wang, Xinzhi and Zhao, Yue and Wang, Yao and Tang, Qinglin and Wang, Yanxin and Zhang, Xiaolin and Kota, Arun Kumar and et al.}, year={2023}, month={Sep} }
 @article{sutherland_rather_sabino_vallabhuneni_wang_popat_kota_2023, title={Hemp-Based Sustainable Slippery Surfaces: Icephobic and Antithrombotic Properties}, volume={11}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.2c06233}, DOI={10.1021/acssuschemeng.2c06233}, abstractNote={With the passage of the 2018 Farm Bill that removed hemp from the Controlled Substances Act altogether, production of hemp is experiencing a renaissance. Building on this revival and re-emergence of hemp, we designed and fabricated hemp-based sustainable and robust slippery surfaces by coating hemp paper with beeswax and subsequently infusing it with hemp oil. A wide variety of aqueous liquids and beverages easily slide on our hemp-based sustainable slippery surfaces, without leaving a trace. We also fabricated hemp-based sustainable slippery surfaces using different textured metals. Our hemp-based sustainable slippery metal surfaces display good icephobic and antithrombotic properties. With these attributes, we envision that our hemp-based sustainable slippery surfaces will pave the path to more safe, non-toxic, and biodegradable or recyclable slippery surfaces for applications in food packaging, anti-icing or de-icing coatings, and antithrombotic medical devices.}, number={6}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Sutherland, Daniel J. and Rather, Adil M. and Sabino, Roberta M. and Vallabhuneni, Sravanthi and Wang, Wei and Popat, Ketul C. and Kota, Arun K.}, year={2023}, month={Feb} }
 @article{kantam_manivasagam_jammu_sabino_vallabhuneni_kim_kota_popat_2023, title={Interaction of Blood and Bacteria with Slippery Hydrophilic Surfaces}, ISSN={["2196-7350"]}, DOI={10.1002/admi.202300564}, abstractNote={Abstract}, journal={ADVANCED MATERIALS INTERFACES}, author={Kantam, Prem and Manivasagam, Vignesh K. and Jammu, Tarun Kumar and Sabino, Roberta Maia and Vallabhuneni, Sravanthi and Kim, Young Jae and Kota, Arun K. and Popat, Ketul C.}, year={2023}, month={Oct} }
 @article{eyegheleme_umashankar_miller_kota_boreyko_2023, title={Oil-Water Separation using Synthetic Trees}, volume={39}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.2c02713}, abstractNote={Existing oil-water filtration techniques require gravity or a pump as the driving force for separation. Here, we demonstrate transpiration-powered oil-water filtration using a synthetic tree, which operates pumplessly and against gravity. From top to bottom, our synthetic tree was composed of: a nanoporous "leaf" to generate suction via evaporation, a vertical array of glass tubes serving as the tree's xylem conduits, and filters attached to the tube inlets to act as the oil-excluding roots. When placing the tree in an oil emulsion bath, filtrate samples were measured to be 97-98% pure water using gravimetry and refractometry. The spontaneous oil-water separation offered by synthetic trees could be useful for applications such as oil spill cleanup, wastewater purification, and oil extraction.}, number={7}, journal={LANGMUIR}, author={Eyegheleme, Ndidi L. and Umashankar, Viverjita and Miller, Danielle N. and Kota, Arun K. and Boreyko, Jonathan B.}, year={2023}, month={Feb}, pages={2520–2528} }
 @article{movafaghi_vallabhuneni_wang_jathar_kota_2023, title={Rapid and Onsite Detection of Fuel Adulteration}, ISSN={["1520-5827"]}, DOI={10.1021/acs.langmuir.3c00578}, abstractNote={In numerous developing countries, the lower cost of subsidized liquid fuels such as kerosene compared to market-rate fuels often results in fuel adulteration. Such misuse of kerosene is hard to detect with conventional detection technologies because they are either time consuming, expensive, not sensitive enough or require well-equipped analytical laboratories. In this work, we developed an inexpensive and easy-to-use device for rapid and onsite detection of fuel adulteration. The working principle of our fuel adulteration detection is sensing changes in the mobility of fuel droplets on non-textured (i.e., smooth) and non-polar solid surfaces. Using our device, we demonstrated rapid detection of diesel (market-rate fuel) adulterated with kerosene (subsidized fuel) at concentrations an order of magnitude below typical adulteration concentrations. We envision that our inexpensive, easy-to-use, and field-deployable device as well as the design strategy will pave the way for novel fuel quality sensors.}, journal={LANGMUIR}, author={Movafaghi, Sanli and Vallabhuneni, Sravanthi and Wang, Wei and Jathar, Shantanu and Kota, Arun K.}, year={2023}, month={Jun} }
 @article{vahabi_vallabhuneni_hedayati_wang_krapf_kipper_miljkovic_kota_2022, title={Designing non-textured, all-solid, slippery hydrophilic surfaces}, volume={5}, ISSN={["2590-2385"]}, DOI={10.1016/j.matt.2022.09.024}, abstractNote={Slippery surfaces are sought after due to their wide range of applications in self-cleaning, drag reduction, fouling-resistance, enhanced condensation, biomedical implants etc. Recently, non-textured, all-solid, slippery surfaces have gained significant attention because of their advantages over super-repellent surfaces and lubricant-infused surfaces. Currently, almost all non-textured, all-solid, slippery surfaces are hydrophobic. In this work, we elucidate the systematic design of non-textured, all-solid, slippery hydrophilic (SLIC) surfaces by covalently grafting polyethylene glycol (PEG) brushes to smooth substrates. Furthermore, we postulate a plateau in slipperiness above a critical grafting density, which occurs when the tethered brush size is equal to the inter-tether distance. Our SLIC surfaces demonstrate exceptional performance in condensation and fouling-resistance compared to non-slippery hydrophilic surfaces and slippery hydrophobic surfaces. Based on these results, SLIC surfaces constitute an emerging class of surfaces with the potential to benefit multiple technological landscapes ranging from thermofluidics to biofluidics.}, number={12}, journal={MATTER}, author={Vahabi, Hamed and Vallabhuneni, Sravanthi and Hedayati, Mohammadhasan and Wang, Wei and Krapf, Diego and Kipper, Matt J. and Miljkovic, Nenad and Kota, Arun K.}, year={2022}, month={Dec}, pages={4502–4512} }
 @article{wang_sun_vallabhuneni_pawlowski_vahabi_nellenbach_brown_scholle_zhao_kota_2022, title={On-demand, remote and lossless manipulation of biofluid droplets}, ISSN={["2051-6355"]}, DOI={10.1039/d2mh00695b}, abstractNote={To minimize exposure of healthcare workers and clinical laboratory personnel to infectious liquids, we designed biofluid manipulators for on-demand handling of liquid droplets, in-plane or out-of-plane, in a remote and lossless manner.}, journal={MATERIALS HORIZONS}, author={Wang, Wei and Sun, Jiefeng and Vallabhuneni, Sravanthi and Pawlowski, Benjamin and Vahabi, Hamed and Nellenbach, Kimberly and Brown, Ashley C. and Scholle, Frank and Zhao, Jianguo and Kota, Arun K.}, year={2022}, month={Sep} }
 @article{channon_menger_wang_carrao_vallabhuneni_kota_henry_2021, title={Design and application of a self-pumping microfluidic staggered herringbone mixer}, volume={25}, ISSN={["1613-4990"]}, DOI={10.1007/s10404-021-02426-x}, number={4}, journal={MICROFLUIDICS AND NANOFLUIDICS}, author={Channon, Robert B. and Menger, Ruth F. and Wang, Wei and Carrao, Daniel B. and Vallabhuneni, Sravanthi and Kota, Arun K. and Henry, Charles S.}, year={2021}, month={Mar} }
 @article{gunay_gnadt_sett_vahabi_kota_miljkovic_2020, title={Droplet Evaporation Dynamics of Low Surface Tension Fluids Using the Steady Method}, volume={36}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.0c02272}, abstractNote={Droplet evaporation governs many heat- and mass-transfer processes germane in nature and industry. In the past 3 centuries, transient techniques have been developed to characterize the evaporation of sessile droplets. These methods have difficulty in reconciling transient effects induced by the droplet shape and size changes during evaporation. Furthermore, investigation of evaporation of microdroplets residing on wetting substrates, or fluids having low surface tensions (<30 mN/m), is difficult to perform using established approaches. Here, we use the steady method to study the microdroplet evaporation dynamics of low surface tension liquids. We start by employing the steady method to benchmark with water droplets having base radii (20 ≤ Rb ≤ 260 μm), apparent advancing contact angle (45° ≤ θa,app ≤ 162°), surface temperature (30 < Ts < 60 °C), and relative humidity (40% < ϕ < 60%). Following validation, evaporation of ethanol (≈22 mN/m), hexane (≈18 mN/m), and dodecane (≈25 mN/m) were studied for 90 ≤ Rb ≤ 400 μm and 10 < Ts < 25 °C. We elucidate the mechanisms governing the observed behavior using heat and mass transport scaling analysis during evaporation, demonstrating our steady technique to be particularly advantageous for microdroplets, where Marangoni and buoyant forces are negligible. Our work not only elucidates the droplet evaporation mechanisms of low surface tension liquids but also demonstrates the steady method as a means to study phase change processes.}, number={46}, journal={LANGMUIR}, author={Gunay, A. Alperen and Gnadt, Marisa and Sett, Soumyadip and Vahabi, Hamed and Kota, Arun K. and Miljkovic, Nenad}, year={2020}, month={Nov}, pages={13860–13871} }
 @article{cha_vahabi_wu_chavan_kim_sett_bosch_wang_kota_miljkovic_2020, title={Dropwise condensation on solid hydrophilic surfaces}, volume={6}, ISSN={["2375-2548"]}, DOI={10.1126/sciadv.aax0746}, abstractNote={Hydrophilic solid surfaces having low contact angle hysteresis can induce stable dropwise condensation.}, number={2}, journal={SCIENCE ADVANCES}, author={Cha, Hyeongyun and Vahabi, Hamed and Wu, Alex and Chavan, Shreyas and Kim, Moon-Kyung and Sett, Soumyadip and Bosch, Stephen A. and Wang, Wei and Kota, Arun K. and Miljkovic, Nenad}, year={2020}, month={Jan} }
 @article{li_li_du_zhang_wang_tong_kota_lee_2020, title={Elucidating the Trade-off between Membrane Wetting Resistance and Water Vapor Flux in Membrane Distillation}, volume={54}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.0c02547}, abstractNote={Membrane distillation (MD) has been receiving considerable attentions as a promising technology for desalinating industrial wastewaters. While hydrophobic membranes are essential for the process, increasing membrane surface hydrophobicity generally leads to the reduction of water vapor flux. In this study, we investigate the mechanisms responsible for this trade-off relation in MD. We prepared hydrophobic membranes with different degrees of wetting resistances through coating quartz fiber membranes with a series of alkylsilane molecules while preserving the fiber structures. A trade-off between wetting resistance and water vapor flux was observed in direct-contact MD experiments, with the least wetting-resistant membrane exhibiting twice as high vapor flux as the most wetting-resistant membrane. Electrochemical impedance analysis, combined with fluorescence microscopy, elucidated that a lower wetting resistance (still water-repelling) allows deeper penetration of liquid-air interfaces into the membrane, resulting in an increased interfacial area and therefore a larger evaporative vapor flux. Finally, we performed osmotic distillation experiments employing anodized alumina membranes that possess straight nanopores with different degrees of wetting resistance, observed no trade-off, and substantiated this proposed mechanism. Our study provides a guideline to tailoring the membrane surface wettability to ensure stable MD operations while maximizing the water recovery rate.}, number={16}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Li, Chenxi and Li, Xuesong and Du, Xuewei and Zhang, Ying and Wang, Wei and Tong, Tiezheng and Kota, Arun Kumar and Lee, Jongho}, year={2020}, month={Aug}, pages={10333–10341} }
 @article{hatoum_vallabhuneni_kota_bark_popat_dasi_2020, title={Impact of superhydrophobicity on the fluid dynamics of a bileaflet mechanical heart valve}, volume={110}, ISSN={["1878-0180"]}, DOI={10.1016/j.jmbbm.2020.103895}, abstractNote={The objective of this study is to evaluate the impact of superhydrophobic coating on the hemodynamics and turbulence characteristics of a bileaflet mechanical valve in the context of evaluating blood damage potential. Two 3D printed bileaflet mechanical valves were hemodynamically tested in a pulse duplicator under physiological pressure and flow conditions. The leaflets of one of the two valves were sprayed with a superhydrophobic coating. Particle Image Velocimetry was performed. Pressure gradients (PG), effective orifice areas (EOA), Reynolds shear stresses (RSS) and instantaneous viscous shear stresses (VSS) were calculated. (a) Without SH coating, the PG was found to be 14.53 ± 0.7 mmHg and EOA 1.44 ± 0.06 cm2. With coating, the PG obtained was 15.21 ± 1.7 mmHg and EOA 1.39 ± 0.07 cm2; (b) during peak systole, the magnitude of RSS with SH coating (110Pa) exceeded that obtained without SH coating (40 Pa) with higher probabilities to develop higher RSS in the immediate wake of the leaflet; (c) The magnitudes range of instantaneous VSS obtained with SH coating were slightly larger than those obtained without SH coating (7.0 Pa versus 5.0 Pa). With Reynolds Shear Stresses and instantaneous Viscous Shear Stresses being correlated with platelet damage, SH coating did not lead to their decrease. While SH coating is known to improve surface properties such as reduced platelet or clot adhesion, the relaxation of the slip condition does not necessarily improve overall hemodynamic performance for the bileaflet mechanical valve design.}, journal={JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS}, author={Hatoum, Hoda and Vallabhuneni, Sravanthi and Kota, Arun Kumar and Bark, David L. and Popat, Ketul C. and Dasi, Lakshmi Prasad}, year={2020}, month={Oct} }
 @article{yan_zhang_sett_feng_zhao_huang_vahabi_kota_chen_miljkovic_2019, title={Droplet Jumping: Effects of Droplet Size, Surface Structure, Pinning, and Liquid Properties}, ISSN={1936-0851 1936-086X}, url={http://dx.doi.org/10.1021/acsnano.8b06677}, DOI={10.1021/acsnano.8b06677}, abstractNote={Coalescence-induced droplet jumping has the potential to enhance the efficiency of a plethora of applications. Although binary droplet jumping is quantitatively understood from energy and hydrodynamic perspectives, multiple aspects that affect jumping behavior, including droplet size mismatch, droplet-surface interaction, and condensate thermophysical properties, remain poorly understood. Here, we develop a visualization technique utilizing microdroplet dispensing to study droplet jumping dynamics on nanostructured superhydrophobic, hierarchical superhydrophobic, and hierarchical biphilic surfaces. We show that on the nanostructured superhydrophobic surface the jumping velocity follows inertial-capillary scaling with a dimensionless velocity of 0.26 and a jumping direction perpendicular to the substrate. A droplet mismatch phase diagram was developed showing that jumping is possible for droplet size mismatch up to 70%. On the hierarchical superhydrophobic surface, jumping behavior was dependent on the ratio between the droplet radius Ri and surface structure length scale L. For small droplets ( Ri ≤ 5 L), the jumping velocity was highly scattered, with a deviation of the jumping direction from the substrate normal as high as 80°. Surface structure length scale effects were shown to vanish for large droplets ( Ri > 5 L). On the hierarchical biphilic surface, similar but more significant scattering of the jumping velocity and direction was observed. Droplet-size-dependent surface adhesion and pinning-mediated droplet rotation were responsible for the reduced jumping velocity and scattered jumping direction. Furthermore, droplet jumping studies of liquids with surface tensions as low as 38 mN/m were performed, further confirming the validity of inertial-capillary scaling for varying condensate fluids. Our work not only demonstrates a powerful platform to study droplet-droplet and droplet-surface interactions but provides insights into the role of fluid-substrate coupling as well as condensate properties during droplet jumping.}, journal={ACS Nano}, publisher={American Chemical Society (ACS)}, author={Yan, Xiao and Zhang, Leicheng and Sett, Soumyadip and Feng, Lezhou and Zhao, Chongyan and Huang, Zhiyong and Vahabi, Hamed and Kota, Arun K. and Chen, Feng and Miljkovic, Nenad}, year={2019}, month={Jan} }
 @article{movafaghi_wang_bark_dasi_popat_kota_2019, title={Hemocompatibility of super-repellent surfaces: current and future}, volume={6}, ISSN={2051-6347 2051-6355}, url={http://dx.doi.org/10.1039/C9MH00051H}, DOI={10.1039/C9MH00051H}, abstractNote={In this review, we critically examine the progress made in characterizing the hemocompatibility of super-repellent surfaces and identify the potential challenges and opportunities for future research.}, number={8}, journal={Materials Horizons}, publisher={Royal Society of Chemistry (RSC)}, author={Movafaghi, Sanli and Wang, Wei and Bark, David L. and Dasi, Lakshmi P. and Popat, Ketul C. and Kota, Arun K.}, year={2019}, pages={1596–1610} }
 @article{sabino_kauk_movafaghi_kota_popat_2019, title={Interaction of blood plasma proteins with superhemophobic titania nanotube surfaces}, volume={21}, ISSN={1549-9634}, url={http://dx.doi.org/10.1016/j.nano.2019.102046}, DOI={10.1016/j.nano.2019.102046}, abstractNote={The need to improve blood biocompatibility of medical devices is urgent. As soon as blood encounters a biomaterial implant, proteins adsorb on its surfaces, often leading to several complications such as thrombosis and failure of the device. Therefore, controlling protein adsorption plays a major role in developing hemocompatible materials. In this study, the interaction of key blood plasma proteins with superhemophobic titania nanotube substrates and the blood clotting responses was investigated. The substrate stability was evaluated and fibrinogen adsorption and thrombin formation from plasma were assessed using ELISA. Whole blood clotting kinetics was also investigated, and Factor XII activation on the substrates was characterized by an in vitro plasma coagulation time assay. The results show that superhemophobic titania nanotubes are stable and considerably decrease surface protein adsorption/Factor XII activation as well as delay the whole blood clotting, and thus can be a promising approach for designing blood contacting medical devices.}, journal={Nanomedicine: Nanotechnology, Biology and Medicine}, publisher={Elsevier BV}, author={Sabino, Roberta Maia and Kauk, Kirsten and Movafaghi, Sanli and Kota, Arun and Popat, Ketul C.}, year={2019}, month={Oct}, pages={102046} }
 @article{movafaghi_cackovic_wang_vahabi_pendurthi_henry_kota_2019, title={Superomniphobic Papers for On‐Paper pH Sensors}, volume={6}, ISSN={2196-7350 2196-7350}, url={http://dx.doi.org/10.1002/admi.201900232}, DOI={10.1002/admi.201900232}, abstractNote={Abstract}, number={13}, journal={Advanced Materials Interfaces}, publisher={Wiley}, author={Movafaghi, Sanli and Cackovic, Matthew D. and Wang, Wei and Vahabi, Hamed and Pendurthi, Anudeep and Henry, Charles S. and Kota, Arun K.}, year={2019}, month={May}, pages={1900232} }
 @article{wang_vahabi_movafaghi_kota_2019, title={Superomniphobic Surfaces with Improved Mechanical Durability: Synergy of Hierarchical Texture and Mechanical Interlocking}, volume={6}, ISSN={["2196-7350"]}, DOI={10.1002/admi.201900538}, abstractNote={Abstract}, number={18}, journal={ADVANCED MATERIALS INTERFACES}, author={Wang, Wei and Vahabi, Hamed and Movafaghi, Sanli and Kota, Arun K.}, year={2019}, month={Sep} }
 @article{wang_du_vahabi_zhao_yin_kota_tong_2019, title={Trade-off in membrane distillation with monolithic omniphobic membranes}, volume={10}, ISSN={["2041-1723"]}, DOI={10.1038/s41467-019-11209-6}, abstractNote={Abstract}, journal={NATURE COMMUNICATIONS}, author={Wang, Wei and Du, Xuewei and Vahabi, Hamed and Zhao, Song and Yin, Yiming and Kota, Arun K. and Tong, Tiezheng}, year={2019}, month={Jul} }
 @article{liu_ma_wang_kota_hu_2018, title={An experimental study on soft PDMS materials for aircraft icing mitigation}, volume={447}, ISSN={0169-4332}, url={http://dx.doi.org/10.1016/j.apsusc.2018.04.032}, DOI={10.1016/j.apsusc.2018.04.032}, abstractNote={A series of experiments were conducted to characterize the anti-/de-icing performances of soft PDMS materials with different shear modulus and to explore their potentials for aircraft icing mitigation. In the present study, a new class of soft PDMS materials with adjustable shear modulus were fabricated by adding different amounts and different molecular weights of non-reactive trimethyl-terminated PDMS (t-PDMS) into the hydrosilylation mixture of vinyl-terminated PDMS (v-PDMS) and hydride-terminated PDMS (h-PDMS). While the soft PDMS materials were found to be hydrophobic with the contact angle of water droplets over the PDMS surfaces being about 110°, the ice adhesion strength over the soft PDMS materials was found to be extremely low (i.e., being less than 10 kPa at −5 °C or two orders of magnitude smaller), in comparison to those of the conventional rigid surface (i.e., being greater than 1000 kPa for Aluminum or the hard plastic material used to make the airfoil/wing model used in the present study). Upon the dynamic impacting of water droplets at relatively high weber number levels pertinent to aircraft inflight icing phenomena (e.g., We = 4000), the soft PDMS surfaces were found to deform dynamically due to the elastic nature of the PDMS materials, which cause the soft PDMS materials acting as “trampolines” to bounce off most of the impinged water mass away from the impacted surfaces. By applying the soft PDMS materials to coat/cover the surface of a NACA 0012 airfoil/wing model, an explorative study was also performed in an Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT) to demonstrate the feasibility of using the soft PDMS materials to mitigate the impact ice accretion process pertinent to aircraft inflight icing phenomena.}, journal={Applied Surface Science}, publisher={Elsevier BV}, author={Liu, Yang and Ma, Liqun and Wang, Wei and Kota, Arun K. and Hu, Hui}, year={2018}, month={Jul}, pages={599–609} }
 @article{bartlet_movafaghi_dasi_kota_popat_2018, title={Antibacterial activity on superhydrophobic titania nanotube arrays}, volume={166}, ISSN={0927-7765}, url={http://dx.doi.org/10.1016/j.colsurfb.2018.03.019}, DOI={10.1016/j.colsurfb.2018.03.019}, abstractNote={Bacterial infections are a serious issue for many implanted medical devices. Infections occur when bacteria colonize the surface of an implant and form a biofilm, a barrier which protects the bacterial colony from antibiotic treatments. Further, the anti-bacterial treatments must also be tailored to the specific bacteria that is causing the infection. The inherent protection of bacteria in the biofilm, differences in bacteria species (gram-positive vs. gram-negative), and the rise of antibiotic-resistant strains of bacteria makes device-acquired infections difficult to treat. Recent research has focused on reducing biofilm formation on medical devices by modifying implant surfaces. Proposed methods have included antibacterial surface coatings, release of antibacterial drugs from surfaces, and materials which promote the adhesion of non-pathogenic bacteria. However, no approach has proven successful in repelling both gram-positive and gram-negative bacteria. In this study, we have evaluated the ability of superhydrophobic surfaces to reduce bacteria adhesion regardless of whether the bacteria are gram-positive or gram-negative. Although superhydrophobic surfaces did not repel bacteria completely, they had minimal bacteria attached after 24 h and more importantly no biofilm formation was observed.}, journal={Colloids and Surfaces B: Biointerfaces}, publisher={Elsevier BV}, author={Bartlet, Kevin and Movafaghi, Sanli and Dasi, Lakshmi Prasad and Kota, Arun K. and Popat, Ketul C.}, year={2018}, month={Jun}, pages={179–186} }
 @article{vahabi_wang_mabry_kota_2018, title={Coalescence-induced jumping of droplets on superomniphobic surfaces with macrotexture}, volume={4}, ISSN={2375-2548}, url={http://dx.doi.org/10.1126/sciadv.aau3488}, DOI={10.1126/sciadv.aau3488}, abstractNote={Superomniphobic surfaces with macrotextures allow coalescence-induced jumping of droplets at Ohnesorge number >1.}, number={11}, journal={Science Advances}, publisher={American Association for the Advancement of Science (AAAS)}, author={Vahabi, Hamed and Wang, Wei and Mabry, Joseph M. and Kota, Arun K.}, year={2018}, month={Nov}, pages={eaau3488} }
 @article{vallabhuneni_movafaghi_wang_kota_2018, title={Superhydrophobic Coatings for Improved Performance of Electrical Insulators}, volume={303}, ISSN={1438-7492}, url={http://dx.doi.org/10.1002/mame.201800313}, DOI={10.1002/mame.201800313}, abstractNote={Abstract}, number={9}, journal={Macromolecular Materials and Engineering}, publisher={Wiley}, author={Vallabhuneni, Sravanthi and Movafaghi, Sanli and Wang, Wei and Kota, Arun K.}, year={2018}, month={Jul}, pages={1800313} }
 @article{jiang_zhao_kota_xi_mutka_xiao_2017, title={A Miniature Water Surface Jumping Robot}, volume={2}, ISSN={2377-3766 2377-3774}, url={http://dx.doi.org/10.1109/lra.2017.2662738}, DOI={10.1109/lra.2017.2662738}, abstractNote={Many small insects such as water striders can leap from water surface. Inspired by their jumping capability, we present the design of a novel, miniature, water surface jumping robot in this paper. Jumping from water surface is more challenging than jumping from ground due to the liquid water surface. We address this problem by using carbon fiber strip to store energy, two wings to flap the water surface, a hollow body to initially support the robot, and an intermittent gear train to charge and release energy. With such a design, the final robot weighs around 12.5 g and has a maximum size of 10 cm. Experimental results show that the robot can jump up to 9.5 cm in height, which is close to the predicted results from a dynamic model developed by us to capture the hydrodynamic behaviors of the robot during the whole jumping process. The research presented in this paper offers a new design of tiny robots for mimicking the water-jumping capability of aquatic insects. The robot, if equipped with sensors, can be employed for aquatic environmental monitoring of water quality.}, number={3}, journal={IEEE Robotics and Automation Letters}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Jiang, Fei and Zhao, Jianguo and Kota, Arun K. and Xi, Ning and Mutka, Matt W. and Xiao, Li}, year={2017}, month={Jul}, pages={1272–1279} }
 @article{vahabi_wang_davies_mabry_kota_2017, title={Coalescence-Induced Self-Propulsion of Droplets on Superomniphobic Surfaces}, volume={9}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/acsami.7b09344}, DOI={10.1021/acsami.7b09344}, abstractNote={We utilized superomniphobic surfaces to systematically investigate the different regimes of coalescence-induced self-propulsion of liquid droplets with a wide range of droplet radii, viscosities, and surface tensions. Our results indicate that the nondimensional jumping velocity Vj* is nearly constant (Vj* ≈ 0.2) in the inertial-capillary regime and decreases in the visco-capillary regime as the Ohnesorge number Oh increases, in agreement with prior work. Within the visco-capillary regime, decreasing the droplet radius R0 results in a more rapid decrease in the nondimensional jumping velocity Vj* compared to increasing the viscosity μ. This is because decreasing the droplet radius R0 increases the inertial-capillary velocity Vic in addition to increasing the Ohnesorge number Oh.}, number={34}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Vahabi, Hamed and Wang, Wei and Davies, Seth and Mabry, Joseph M. and Kota, Arun K.}, year={2017}, month={Aug}, pages={29328–29336} }
 @article{pendurthi_movafaghi_wang_shadman_yalin_kota_2017, title={Fabrication of Nanostructured Omniphobic and Superomniphobic Surfaces with Inexpensive CO2 Laser Engraver}, volume={9}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/acsami.7b06924}, DOI={10.1021/acsami.7b06924}, abstractNote={Superomniphobic surfaces (i.e., surfaces that are extremely repellent to both high surface tension liquids like water and low surface tension liquid like oils) can be fabricated through a combination of surface chemistry that imparts low solid surface energy with a re-entrant surface texture. Recently, surface texturing with lasers has received significant attention because laser texturing is scalable, solvent-free, and can produce a monolithic texture on virtually any material. In this work, we fabricated nanostructured omniphobic and superomniphobic surfaces with a variety of materials using a simple, inexpensive and commercially available CO2 laser engraver. Further, we demonstrated that the nanostructured omniphobic and superomniphobic surfaces fabricated using our laser texturing technique can be used to design patterned surfaces, surfaces with discrete domains of the desired wettability, and on-surface microfluidic devices.}, number={31}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Pendurthi, Anudeep and Movafaghi, Sanli and Wang, Wei and Shadman, Soran and Yalin, Azer P. and Kota, Arun K.}, year={2017}, month={Jul}, pages={25656–25661} }
 @article{vahabi_wang_popat_kwon_holland_kota_2017, title={Metallic superhydrophobic surfaces via thermal sensitization}, volume={110}, ISSN={0003-6951 1077-3118}, url={http://dx.doi.org/10.1063/1.4989577}, DOI={10.1063/1.4989577}, abstractNote={Superhydrophobic surfaces (i.e., surfaces extremely repellent to water) allow water droplets to bead up and easily roll off from the surface. While a few methods have been developed to fabricate metallic superhydrophobic surfaces, these methods typically involve expensive equipment, environmental hazards, or multi-step processes. In this work, we developed a universal, scalable, solvent-free, one-step methodology based on thermal sensitization to create appropriate surface texture and fabricate metallic superhydrophobic surfaces. To demonstrate the feasibility of our methodology and elucidate the underlying mechanism, we fabricated superhydrophobic surfaces using ferritic (430) and austenitic (316) stainless steels (representative alloys) with roll off angles as low as 4° and 7°, respectively. We envision that our approach will enable the fabrication of superhydrophobic metal alloys for a wide range of civilian and military applications.}, number={25}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={Vahabi, Hamed and Wang, Wei and Popat, Ketul C. and Kwon, Gibum and Holland, Troy B. and Kota, Arun K.}, year={2017}, month={Jun}, pages={251602} }
 @article{wang_salazar_vahabi_joshi-imre_voit_kota_2017, title={Metamorphic Superomniphobic Surfaces}, volume={29}, ISSN={0935-9648}, url={http://dx.doi.org/10.1002/adma.201700295}, DOI={10.1002/adma.201700295}, abstractNote={Superomniphobic surfaces are extremely repellent to virtually all liquids. By combining superomniphobicity and shape memory effect, metamorphic superomniphobic (MorphS) surfaces that transform their morphology in response to heat are developed. Utilizing the MorphS surfaces, the distinctly different wetting transitions of liquids with different surface tensions are demonstrated and the underlying physics is elucidated. Both ex situ and in situ wetting transitions on the MorphS surfaces are solely due to transformations in morphology of the surface texture. It is envisioned that the robust MorphS surfaces with reversible wetting transition will have a wide range of applications including rewritable liquid patterns, controlled drug release systems, lab‐on‐a‐chip devices, and biosensors.}, number={27}, journal={Advanced Materials}, publisher={Wiley}, author={Wang, Wei and Salazar, Joshua and Vahabi, Hamed and Joshi-Imre, Alexandra and Voit, Walter E. and Kota, Arun K.}, year={2017}, month={May}, pages={1700295} }
 @article{bartlet_movafaghi_kota_popat_2017, title={Superhemophobic titania nanotube array surfaces for blood contacting medical devices}, volume={7}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/c7ra03373g}, DOI={10.1039/c7ra03373g}, abstractNote={Appropriate hemocompatible response for blood-contacting medical devices is necessary to prevent device failure.}, number={56}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Bartlet, Kevin and Movafaghi, Sanli and Kota, Arun and Popat, Ketul C.}, year={2017}, pages={35466–35476} }
 @article{beemer_wang_kota_2016, title={Durable gels with ultra-low adhesion to ice}, volume={4}, ISSN={2050-7488 2050-7496}, url={http://dx.doi.org/10.1039/c6ta07262c}, DOI={10.1039/c6ta07262c}, abstractNote={Building on principles of adhesion mechanics, we developed novel PDMS gels with ultra-low adhesion to ice and outstanding mechanical durability.}, number={47}, journal={Journal of Materials Chemistry A}, publisher={Royal Society of Chemistry (RSC)}, author={Beemer, Darryl L. and Wang, Wei and Kota, Arun K.}, year={2016}, pages={18253–18258} }
 @article{vahabi_wang_movafaghi_kota_2016, title={Free-Standing, Flexible, Superomniphobic Films}, volume={8}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/acsami.6b06333}, DOI={10.1021/acsami.6b06333}, abstractNote={Fabrication of most superomniphobic surfaces requires complex process conditions or specialized and expensive equipment or skilled personnel. In order to circumvent these issues and make them end-user-friendly, we developed the free-standing, flexible, superomniphobic films. These films can be stored and delivered to the end-users, who can readily attach them to virtually any surface (even irregular shapes) and impart superomniphobicity. The hierarchical structure, the re-entrant texture, and the low solid surface energy render our films superomniphobic for a wide variety of liquids. We demonstrate that our free-standing, flexible, superomniphobic films have applications in enhanced chemical resistance and enhanced weight bearing.}, number={34}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Vahabi, Hamed and Wang, Wei and Movafaghi, Sanli and Kota, Arun K.}, year={2016}, month={Aug}, pages={21962–21967} }
 @article{movafaghi_leszczak_wang_sorkin_dasi_popat_kota_2016, title={Hemocompatibility of Superhemophobic Titania Surfaces}, volume={6}, ISSN={2192-2640}, url={http://dx.doi.org/10.1002/adhm.201600717}, DOI={10.1002/adhm.201600717}, abstractNote={The hemocompatibility of superhemophobic surfaces is investigated and compared with that of hemophobic surfaces and hemophilic surfaces. This analysis indicates that only those superhemophobic surfaces with a robust Cassie-Baxter state display significantly lower platelet adhesion and activation. It is envisioned that the understanding gained through this work will lead to the fabrication of improved hemocompatible, superhemophobic medical implants.}, number={4}, journal={Advanced Healthcare Materials}, publisher={Wiley}, author={Movafaghi, Sanli and Leszczak, Victoria and Wang, Wei and Sorkin, Jonathan A. and Dasi, Lakshmi P. and Popat, Ketul C. and Kota, Arun K.}, year={2016}, month={Dec}, pages={1600717} }
 @article{bark_vahabi_bui_movafaghi_moore_kota_popat_dasi_2016, title={Hemodynamic Performance and Thrombogenic Properties of a Superhydrophobic Bileaflet Mechanical Heart Valve}, volume={45}, ISSN={0090-6964 1573-9686}, url={http://dx.doi.org/10.1007/s10439-016-1618-2}, DOI={10.1007/s10439-016-1618-2}, abstractNote={In this study, we explore how blood-material interactions and hemodynamics are impacted by rendering a clinical quality 25 mm St. Jude Medical Bileaflet mechanical heart valve (BMHV) superhydrophobic (SH) with the aim of reducing thrombo-embolic complications associated with BMHVs. Basic cell adhesion is evaluated to assess blood-material interactions, while hemodynamic performance is analyzed with and without the SH coating. Results show that a SH coating with a receding contact angle (CA) of 160° strikingly eliminates platelet and leukocyte adhesion to the surface. Alternatively, many platelets attach to and activate on pyrolytic carbon (receding CA = 47), the base material for BMHVs. We further show that the performance index increases by 2.5% for coated valve relative to an uncoated valve, with a maximum possible improved performance of 5%. Both valves exhibit instantaneous shear stress below 10 N/m2 and Reynolds Shear Stress below 100 N/m2. Therefore, a SH BMHV has the potential to relax the requirement for antiplatelet and anticoagulant drug regimens typically required for patients receiving MHVs by minimizing blood-material interactions, while having a minimal impact on hemodynamics. We show for the first time that SH-coated surfaces may be a promising direction to minimize thrombotic complications in complex devices such as heart valves.}, number={2}, journal={Annals of Biomedical Engineering}, publisher={Springer Science and Business Media LLC}, author={Bark, David L. and Vahabi, Hamed and Bui, Hieu and Movafaghi, Sanli and Moore, Brandon and Kota, Arun K. and Popat, Ketul and Dasi, Lakshmi P.}, year={2016}, month={Apr}, pages={452–463} }
 @article{wang_lockwood_boyd_davidson_movafaghi_vahabi_khetani_kota_2016, title={Superhydrophobic Coatings with Edible Materials}, volume={8}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/acsami.6b06958}, DOI={10.1021/acsami.6b06958}, abstractNote={We used FDA-approved, edible materials to fabricate superhydrophobic coatings in a simple, low cost, scalable, single step process. Our coatings display high contact angles and low roll off angles for a variety of liquid products consumed daily and facilitate easy removal of liquids from food containers with virtually no residue. Even at high concentrations, our coatings are nontoxic, as shown using toxicity tests.}, number={29}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Wang, Wei and Lockwood, Karsten and Boyd, Lewis M. and Davidson, Matthew D. and Movafaghi, Sanli and Vahabi, Hamed and Khetani, Salman R. and Kota, Arun K.}, year={2016}, month={Jul}, pages={18664–18668} }
 @article{movafaghi_wang_metzger_williams_williams_kota_2016, title={Tunable superomniphobic surfaces for sorting droplets by surface tension}, volume={16}, ISSN={1473-0197 1473-0189}, url={http://dx.doi.org/10.1039/c6lc00673f}, DOI={10.1039/c6lc00673f}, abstractNote={Utilizing tunable superomniphobic surfaces with flower-like TiO2 nanostructures, we fabricated a simple device that can sort droplets by surface tension.}, number={17}, journal={Lab on a Chip}, publisher={Royal Society of Chemistry (RSC)}, author={Movafaghi, S. and Wang, W. and Metzger, A. and Williams, D. D. and Williams, J. D. and Kota, A. K.}, year={2016}, pages={3204–3209} }
 @article{kobaku_kwon_kota_karunakaran_wong_lee_tuteja_2015, title={Wettability Engendered Templated Self-assembly (WETS) for Fabricating Multiphasic Particles}, volume={7}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/am507964k}, DOI={10.1021/am507964k}, abstractNote={Precise control over the geometry and chemistry of multiphasic particles is of significant importance for a wide range of applications. In this work, we have developed one of the simplest methodologies for fabricating monodisperse, multiphasic micro- and nanoparticles possessing almost any composition, projected shape, modulus, and dimensions as small as 25 nm. The synthesis methodology involves the fabrication of a nonwettable surface patterned with monodisperse, wettable domains of different sizes and shapes. When such patterned templates are dip-coated with polymer solutions or particle dispersions, the liquids, and consequently the polymer or the particles, preferentially self-assemble within the wettable domains. Utilizing this phenomenon, we fabricate multiphasic assemblies with precisely controlled geometry and composition through multiple, layered depositions of polymers and/or particles within the patterned domains. Upon releasing these multiphasic assemblies from the template using a sacrificial layer, we obtain multiphasic particles. The templates can then be readily reused (over 20 times in our experiments) for fabricating a new batch of particles, enabling a rapid, inexpensive, and easily reproducible method for large-scale manufacturing of multiphasic particles.}, number={7}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Kobaku, Sai P. R. and Kwon, Gibum and Kota, Arun K. and Karunakaran, Raghuraman G. and Wong, Philip and Lee, Duck Hyun and Tuteja, Anish}, year={2015}, month={Feb}, pages={4075–4080} }
 @article{kota_kwon_tuteja_2014, title={The design and applications of superomniphobic surfaces}, volume={6}, ISSN={1884-4049 1884-4057}, url={http://dx.doi.org/10.1038/am.2014.34}, DOI={10.1038/am.2014.34}, abstractNote={Surfaces that display contact angles >150° along with low contact angle hysteresis with essentially all high and low surface tension liquids, including water, oils and alcohols, are known as superomniphobic surfaces. Such surfaces have a range of commercial applications, including self-cleaning, non-fouling, stain-free clothing, drag reduction, corrosion prevention and separation of liquids. Such surfaces have thus generated immense academic and industrial interest in recent years. In this review, we discuss the systematic design of superomniphobic surfaces. In particular, we discuss the significance of surface energy, roughness and the critical role of re-entrant texture in obtaining the so-called Cassie–Baxter state with low surface tension liquids. We also discuss how hierarchical scales of texture can yield high contact angles and decrease the contact angle hysteresis of superomniphobic surfaces by reducing the solid–liquid contact area. On the basis of this understanding, we discuss dimensionless design parameters that allow for the systematic design of superomniphobic surfaces. We also review the current literature on superomniphobic surfaces, paying particular attention to surfaces that demonstrate good mechanical, chemical and radiation durability—traits that are essential for any commercial application of superomniphobic surfaces. Finally, we conclude by identifying the unresolved challenges in the fabrication of durable superomniphobic surfaces and highlight the future needs in the field. Surfaces that display contact angles >150° along with a low contact angle hysteresis for both low and high surface tension liquids are known as superomniphobic surfaces. Such surfaces have several applications, including self-cleaning, non-fouling, stain-free clothing, drag reduction, corrosion prevention and separation of liquids. In this review, we discuss the design criteria, recent studies, applications, challenges and potential of superomniphobic surfaces. Surfaces that strongly repel low surface tension liquids (e.g. oils and alcohols) are classified as superoleophobic and those that strongly repel high surface tension liquids (e.g. water) are classified as superhydrophobic. However, if a surface shows both these characteristics, it can be considered superomniphobic. Liquid droplets on superomniphobic surfaces roll off very easily and, as a result, these surfaces are attractive as non-fouling coatings, self-cleaning surfaces and liquid-separation techniques. Anish Tuteja at the University of Michigan, United States, and colleagues review the design principles required to fabricate superomniphobic surfaces. They discuss surface energy, roughness and hierarchical scales of surface texture, and recognize the importance of re-entrant textures (i.e. convex topography) to achieve superomniphobicity. Several examples of superomniphobic surfaces are presented with particular focus on the need to improve chemical and mechanical durability, to realize their full potential in commercial and industrial applications.}, number={7}, journal={NPG Asia Materials}, publisher={Springer Science and Business Media LLC}, author={Kota, Arun K and Kwon, Gibum and Tuteja, Anish}, year={2014}, month={Jul}, pages={e109–e109} }
 @article{yoon_kota_bhaskar_tuteja_lahann_2013, title={Amphiphilic Colloidal Surfactants Based on Electrohydrodynamic Co-jetting}, volume={5}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/am403516h}, DOI={10.1021/am403516h}, abstractNote={A novel synthetic route for the preparation of amphiphilic Janus particles based on electrohydrodynamic cojetting has been developed. In this approach, selective encapsulation of hydrophobic fluorodecyl-polyhedral oligomeric silsesquioxane (F-POSS) in one compartment and a poly(vinyl alcohol) in the second compartment results in colloidal particles with surfactant-like properties including the self-organization at oil-water and air-water interfaces. Successful localization of the respective polymers in different compartments of the same particle is confirmed by a combination of fluorescence microscopy, vibrational spectroscopy, and ζ-potential measurements. We believe that this straightforward synthetic approach may lead to a diverse class of surface-active colloids that will have significant relevance ranging from basic scientific studies to immediate applications in areas, such as pharmaceutical sciences or cosmetics.}, number={21}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Yoon, Jaewon and Kota, Arun and Bhaskar, Srijanani and Tuteja, Anish and Lahann, Joerg}, year={2013}, month={Oct}, pages={11281–11287} }
 @article{kota_tuteja_2013, title={High-efficiency, ultrafast separation of emulsified oil–water mixtures}, volume={5}, ISSN={1884-4049 1884-4057}, url={http://dx.doi.org/10.1038/am.2013.34}, DOI={10.1038/am.2013.34}, abstractNote={Multiple oil spill disasters over the last few years have highlighted the challenges of effective oil–water separation. The separation of oil–water micro- and nano-emulsions (emulsions with dispersed droplet sizes in the micro- or nano-meter range) can be particularly difficult.1, 2 Shi et al.3 from the Chinese Academy of Sciences in Suzhou and Beijing have now developed ultrathin carbon nanotube membranes that can separate a wide range of oil–water micro- and nano-emulsions with separation efficiency >99.9%. Perhaps more significantly, the separation fluxes are 2–3 orders of magnitude higher than those obtained with current commercially available separation membranes.}, number={8}, journal={NPG Asia Materials}, publisher={Springer Science and Business Media LLC}, author={Kota, Arun K and Tuteja, Anish}, year={2013}, month={Aug}, pages={e58–e58} }
 @article{kota_mabry_tuteja_2013, title={Superoleophobic surfaces: design criteria and recent studies}, volume={1}, ISSN={2050-6252 2050-6260}, url={http://dx.doi.org/10.1680/si.12.00017}, DOI={10.1680/si.12.00017}, abstractNote={ Surfaces that display contact angles greater than 150° along with a low contact angle hysteresis for low surface tension liquids such as oils and alcohols are known as superoleophobic surfaces. Such surfaces are of interest for a diverse array of applications including self-cleaning, nonfouling, stain-free clothing and spill-resistant protective wear, drag reduction, microrobots for aqueous and chemical environments and icephobicity. Recently, significant advances have been made in understanding the criteria required to design superoleophobic surfaces. In this article, the authors discuss the roles of surface energy and roughness, the critical role of re-entrant texture and the role of hierarchical structure in fabricating superoleophobic surfaces. On the basis of this understanding, the authors also discuss two design parameters that allow for the systematic design of superoleophobic surfaces. The authors also summarize the recent studies on superoleophobic surfaces and emphasize the need for careful and diligent characterization. Finally, the authors conclude with the major challenges and opportunities for research on superoleophobic surfaces. }, number={2}, journal={Surface Innovations}, publisher={Thomas Telford Ltd.}, author={Kota, Arun K. and Mabry, Joseph M. and Tuteja, Anish}, year={2013}, month={Jun}, pages={71–83} }
 @article{pan_kota_mabry_tuteja_2013, title={Superomniphobic Surfaces for Effective Chemical Shielding}, volume={135}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/ja310517s}, DOI={10.1021/ja310517s}, abstractNote={Superomniphobic surfaces display contact angles >150° and low contact angle hysteresis with essentially all contacting liquids. In this work, we report surfaces that display superomniphobicity with a range of different non-Newtonian liquids, in addition to superomniphobicity with a wide range of Newtonian liquids. Our surfaces possess hierarchical scales of re-entrant texture that significantly reduce the solid-liquid contact area. Virtually all liquids including concentrated organic and inorganic acids, bases, and solvents, as well as viscoelastic polymer solutions, can easily roll off and bounce on our surfaces. Consequently, they serve as effective chemical shields against virtually all liquids--organic or inorganic, polar or nonpolar, Newtonian or non-Newtonian.}, number={2}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Pan, Shuaijun and Kota, Arun K. and Mabry, Joseph M. and Tuteja, Anish}, year={2013}, pages={578–581} }
 @article{kota_choi_tuteja_2013, title={Superomniphobic surfaces: Design and durability}, volume={38}, ISSN={0883-7694 1938-1425}, url={http://dx.doi.org/10.1557/mrs.2013.101}, DOI={10.1557/mrs.2013.101}, abstractNote={Abstract}, number={5}, journal={MRS Bulletin}, publisher={Cambridge University Press (CUP)}, author={Kota, Arun K. and Choi, Wonjae and Tuteja, Anish}, year={2013}, month={May}, pages={383–390} }
 @article{kota_li_mabry_tuteja_2012, title={Hierarchically Structured Superoleophobic Surfaces with Ultralow Contact Angle Hysteresis}, volume={24}, ISSN={0935-9648}, url={http://dx.doi.org/10.1002/adma.201202554}, DOI={10.1002/adma.201202554}, abstractNote={Hierarchically structured, superoleophobic surfaces are demonstrated that display one of the lowest contact angle hysteresis values ever reported - even with extremely low-surface-tension liquids such as n-heptane. Consequently, these surfaces allow, for the first time, even ≈2 μL n-heptane droplets to bounce and roll-off at tilt angles. ≤ 2°.}, number={43}, journal={Advanced Materials}, publisher={Wiley}, author={Kota, Arun K. and Li, Yongxin and Mabry, Joseph M. and Tuteja, Anish}, year={2012}, month={Aug}, pages={5838–5843} }
 @article{kota_kwon_choi_mabry_tuteja_2012, title={Hygro-responsive membranes for effective oil–water separation}, volume={3}, ISSN={2041-1723}, url={http://dx.doi.org/10.1038/ncomms2027}, DOI={10.1038/ncomms2027}, abstractNote={There is a critical need for new energy-efficient solutions to separate oil-water mixtures, especially those stabilized by surfactants. Traditional membrane-based separation technologies are energy-intensive and limited, either by fouling or by the inability of a single membrane to separate all types of oil-water mixtures. Here we report membranes with hygro-responsive surfaces, which are both superhydrophilic and superoleophobic, in air and under water. Our membranes can separate, for the first time, a range of different oil-water mixtures in a single-unit operation, with >99.9% separation efficiency, by using the difference in capillary forces acting on the two phases. Our separation methodology is solely gravity-driven and consequently is expected to be highly energy-efficient. We anticipate that our separation methodology will have numerous applications, including the clean-up of oil spills, wastewater treatment, fuel purification and the separation of commercially relevant emulsions.}, number={1}, journal={Nature Communications}, publisher={Springer Science and Business Media LLC}, author={Kota, Arun K. and Kwon, Gibum and Choi, Wonjae and Mabry, Joseph M. and Tuteja, Anish}, year={2012}, month={Jan} }
 @article{kwon_kota_li_sohani_mabry_tuteja_2012, title={On-Demand Separation of Oil-Water Mixtures}, volume={24}, ISSN={0935-9648}, url={http://dx.doi.org/10.1002/adma.201201364}, DOI={10.1002/adma.201201364}, abstractNote={In this work, the first-ever membrane-based single unit operation that enables gravity driven, on-demand separation of various oil-water mixtures is developed. Using this methodology, the on-demand separation of free oil and water, oil-in-water emulsions, and water-in-oil emulsions is demonstrated, with ≥99.9% separation efficiency. A scaled-up apparatus to separate larger quantities (several liters) of oil-water emulsions is also developed.}, number={27}, journal={Advanced Materials}, publisher={Wiley}, author={Kwon, Gibum and Kota, Arun. K. and Li, Yongxin and Sohani, Ameya and Mabry, Joseph M. and Tuteja, Anish}, year={2012}, month={Jun}, pages={3666–3671} }
 @article{kobaku_kota_lee_mabry_tuteja_2012, title={Patterned Superomniphobic-Superomniphilic Surfaces: Templates for Site-Selective Self-Assembly}, volume={124}, ISSN={0044-8249}, url={http://dx.doi.org/10.1002/ange.201202823}, DOI={10.1002/ange.201202823}, abstractNote={Intelligente Oberflächen: Strukturierte superomniphobe und superomniphile Oberflächen wurden hergestellt. Die möglichen Anwendungen dieser Oberflächen sind vielfältig, z. B. für Mikroreaktoren zur Verbesserung des Wärmetransfers beim Kondensieren und Sieden von Flüssigkeiten mit niedriger Oberflächenspannung und zur Herstellung von maßgeschneiderten Polymerarrays und Mikropartikeln unterschiedlicher Größe und Form.}, number={40}, journal={Angewandte Chemie}, publisher={Wiley}, author={Kobaku, Sai P. R. and Kota, Arun K. and Lee, Duck Hyun and Mabry, Joseph M. and Tuteja, Anish}, year={2012}, month={Oct}, pages={10256–10260} }
 @article{choi_kota_winey_2010, title={Micellar Morphology in Sulfonated Pentablock Copolymer Solutions}, volume={49}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/ie1002476}, DOI={10.1021/ie1002476}, abstractNote={The morphology of solutions of poly[t-butyl styrene-b-hydrogenated isoprene-b-sulfonated styrene-b-hydrogenated isoprene-b-t-butyl styrene] (tBS-HI-SS-HI-tBS) pentablock copolymers with a range of sulfonation levels was studied by small-angle X-ray scattering and transmission electron microscopy. For dilute pentablock copolymer solutions, TEM confirms the spherical micellar morphology. Small-angle X-ray scattering results and their interpretation using the Kinning−Thomas model reveal that sulfonated pentablock copolymer solutions with all levels of sulfonation exhibit spherical micellar morphologies with a core of SS and a corona of solvated HI-tBS. Both the radius of the micelle core and the closest approach distance between cores increase with sulfonation level, while the number density of micelles decreases. The calculated fraction of micelles per unit volume shows an increase and then a plateau with sulfonation level. The manipulation of micelle size dramatically impacts the processability.}, number={23}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Choi, Jae-Hong and Kota, Arun and Winey, Karen I.}, year={2010}, month={Dec}, pages={12093–12097} }
 @article{gershon_cole_kota_bruck_2010, title={Nanomechanical characterization of dispersion and its effects in nano-enhanced polymers and polymer composites}, volume={45}, ISSN={0022-2461 1573-4803}, url={http://dx.doi.org/10.1007/s10853-010-4597-y}, DOI={10.1007/s10853-010-4597-y}, number={23}, journal={Journal of Materials Science}, publisher={Springer Science and Business Media LLC}, author={Gershon, Alan L. and Cole, Daniel P. and Kota, Arun K. and Bruck, Hugh A.}, year={2010}, month={Jun}, pages={6353–6364} }
 @article{gershon_kota_bruck_2009, title={Characterization of Quasi-static Mechanical Properties of Polymer Nanocomposites Using a New Combinatorial Approach}, volume={43}, ISSN={0021-9983 1530-793X}, url={http://dx.doi.org/10.1177/0021998309345311}, DOI={10.1177/0021998309345311}, abstractNote={ Recently, it has become very important to rapidly characterize the processing-structure-property relationships in polymer nanocomposites using minimal quantities of expensive nanoscale fillers. To address this issue, we present a new combinatorial approach developed for characterizing the variation in mechanical properties as a function of filler composition in polymer nanocomposites. The fundamental basis for the combinatorial approach is the generation of compositional gradients through transient operation of a twin-screw extruder (TSE). The compositional variation in the specimens could be rapidly predicted a priori using a convolution process model and was verified a posteriori using pycnometry measurements and thermogravimetric analysis. To characterize the quasi-static mechanical properties along the compositional gradient, sub-scale specimens that are proportional in size to ASTM type I specimens but with a gage section that is a factor of 10 smaller, were tested using a microtensile tester. The properties of the sub-scale specimens processed in the combinatorial approach correlated well with those of sub-scale specimens of similar composition processed in steady-state, thereby indicating that the properties were unaffected by the transient operation of the TSE. Furthermore, the quasi-static mechanical properties of the steady-state ASTM type I standard specimens were compared with those of the sub-scale specimens to determine the effect of specimen size. The results were nearly identical, except the increased size of the ASTM type I standard specimens resulted in substantial reductions in ductility that are most likely due to an increase in the number of processing-related defects. }, number={22}, journal={Journal of Composite Materials}, publisher={SAGE Publications}, author={Gershon, Alan L. and Kota, Arun K. and Bruck, Hugh A.}, year={2009}, month={Aug}, pages={2587–2598} }
 @article{kota_2009, title={Commentary: Polymer/carbon-nanotube nanocomposites: from innovation to commercialization}, volume={3}, ISSN={1934-2608}, url={http://dx.doi.org/10.1117/1.3248365}, DOI={10.1117/1.3248365}, abstractNote={With the availability of new and improved processing and characterization techniques, researchers have become increasingly interested over the past decade in altering homogeneous polymeric-matrix materials by adding nanoscale fillers (less than 100 nm in at least one dimension) to create what are now being called polymer nanocomposites. The most notable structural feature of the polymer nanocomposites is the enormous interfacial area between the nanoscale fillers and the polymer matrix. This becomes clearly evident when polymer composites containing microscale fillers are compared with those containing nanoscale fillers. For example, consider two different polymer composites containing the same volume fraction of the filler, but one with 1-µm-diameter spherical filler particles and another with 1-nmdiameter ones. As the radius of the spherical filler particles drops from the microscale to the nanoscale, the number of filler particles increases by one billion times, the mean particle– particle separation decreases by one thousand times, and the total interfacial area increases by a thousand times. Due to the large surface area of nanoscale fillers, polymer nanocomposites have a large volume of interfacial polymer, as shown in Fig. 1. Almost the entire matrix can be interfacial polymer even at filler volume fractions as small as 5 vol.% [1]. This is critical because the interfacial polymer can have significantly different morphology and material properties compared to the bulk polymer (which is not at the interface). Thus, the resulting polymer nanocomposite may exhibit synergistic material properties that are well beyond those predicted by simple additive models for traditional microcomposites. In polymer nanocomposite literature, this synergy is sometimes termed as the nano effect or the nano advantage.}, number={1}, journal={Journal of Nanophotonics}, publisher={SPIE-Intl Soc Optical Eng}, author={Kota, Arun K.}, year={2009}, month={Sep}, pages={030307} }
 @article{kota_kerzner_bigio_bruck_powell_2008, title={Characterization of processing effects in HIPS-CNF composites using thermogravimetric analysis}, volume={48}, ISSN={0032-3888 1548-2634}, url={http://dx.doi.org/10.1002/pen.21059}, DOI={10.1002/pen.21059}, abstractNote={Abstract}, number={6}, journal={Polymer Engineering & Science}, publisher={Wiley}, author={Kota, Arun K. and Kerzner, Rachel and Bigio, David I. and Bruck, Hugh A. and Powell, Dan}, year={2008}, month={Jun}, pages={1120–1125} }
 @article{kota_murphy_strohmer_bigio_bruck_powell_2008, title={Combinatorial development of polymer nanocomposites using transient processing conditions in twin screw extrusion}, volume={54}, ISSN={0001-1541 1547-5905}, url={http://dx.doi.org/10.1002/aic.11505}, DOI={10.1002/aic.11505}, abstractNote={Abstract}, number={7}, journal={AIChE Journal}, publisher={Wiley}, author={Kota, Arun K. and Murphy, Larry and Strohmer, Timo and Bigio, David I. and Bruck, Hugh A. and Powell, Dan}, year={2008}, pages={1895–1900} }
 @article{cipriano_kota_gershon_laskowski_kashiwagi_bruck_raghavan_2008, title={Conductivity enhancement of carbon nanotube and nanofiber-based polymer nanocomposites by melt annealing}, volume={49}, ISSN={0032-3861}, url={http://dx.doi.org/10.1016/j.polymer.2008.08.057}, DOI={10.1016/j.polymer.2008.08.057}, abstractNote={The addition of multi-walled carbon nanotubes (MWCNTs) or carbon nanofibers (CNFs) to polymeric melts offers a convenient route to obtain highly conductive plastics. However, when these materials are melt processed, their conductivity can be lost. Here, it is shown that conductivities can be recovered through melt annealing at temperatures above the polymer's glass transition temperature (Tg). We demonstrate these results for both MWCNT and CNF-based composites in polystyrene (PS). The mechanism behind the conductivity increase is elucidated through modeling. It involves a transition from aligned, unconnected particles prior to annealing to an interconnected network after annealing through viscoelastic relaxation of the polymer. Such re-arrangement is directly visualized for the case of the CNF-based composites using confocal microscopy. The annealing-induced increase in particle connectivity is also reflected in dynamic rheological measurements on both MWCNT and CNF composites as an increase in their elastic moduli at low frequencies.}, number={22}, journal={Polymer}, publisher={Elsevier BV}, author={Cipriano, Bani H. and Kota, Arun K. and Gershon, Alan L. and Laskowski, Conrad J. and Kashiwagi, Takashi and Bruck, Hugh A. and Raghavan, Srinivasa R.}, year={2008}, month={Oct}, pages={4846–4851} }
 @article{kota_cipriano_duesterberg_gershon_powell_raghavan_bruck_2007, title={Electrical and Rheological Percolation in Polystyrene/MWCNT Nanocomposites}, volume={40}, ISSN={0024-9297 1520-5835}, url={http://dx.doi.org/10.1021/ma0711792}, DOI={10.1021/ma0711792}, abstractNote={A systematic electrical and rheological characterization of percolation in commercial polydisperse polystyrene (PS) nanocomposites containing multiwall carbon nanotubes (MWCNTs) is presented. The MWCNTs confer appreciable electrical conductivities (up to ca. 1 S/m) to these nanocomposites at a concentration of 8 vol %. In addition to enhancing the electrical properties, even at small concentrations (ca. 2 vol %), MWCNTs significantly enhance the rheological properties of PS melts. At concentrations exceeding 2 vol %, a plateau appears in the storage modulus G‘ at low frequencies, indicating the formation of a percolated MWCNT network that responds elastically over long timescales. Network formation, in turn, implies a diverging complex viscosity vs complex modulus curve. A focus of this study is on the correlation between electrical and rheological properties at the onset of percolation. The experimental results indicate that the elastic load transfer and electrical conductivity are far more sensitive to ...}, number={20}, journal={Macromolecules}, publisher={American Chemical Society (ACS)}, author={Kota, Arun K. and Cipriano, Bani H. and Duesterberg, Matthew K. and Gershon, Alan L. and Powell, Dan and Raghavan, Srinivasa R. and Bruck, Hugh A.}, year={2007}, month={Oct}, pages={7400–7406} }
 @article{kota_cipriano_powell_raghavan_bruck_2007, title={Quantitative characterization of the formation of an interpenetrating phase composite in polystyrene from the percolation of multiwalled carbon nanotubes}, volume={18}, ISSN={0957-4484 1361-6528}, url={http://dx.doi.org/10.1088/0957-4484/18/50/505705}, DOI={10.1088/0957-4484/18/50/505705}, abstractNote={For the first time, an interpenetrating phase polymer nanocomposite formed by the percolation of multiwalled carbon nanotubes (MWCNTs) in polystyrene (PS) has been quantitatively characterized through electrical conductivity measurements and melt rheology. Both sets of measurements, in conjunction with scanning electron microscopy (SEM) images, indicate the presence of a continuous phase of percolated MWCNTs appearing at particle concentrations exceeding 2 vol% MWCNTs in PS. To quantify the amount of this continuous phase present in the PS/MWCNT composite, electrical conductivity data at various MWCNT concentrations, β, are correlated with a proposed degree of percolation, , developed using a conventional power-law formula with and without a percolation threshold. To quantify the properties of the interpenetrating phase polymer nanocomposite, the PS/MWCNT composite is treated as a combination of two phases: a continuous phase consisting of a pseudo-solid-like network of percolated MWCNTs, and a continuous PS phase reinforced by non-interacting MWCNTs. The proposed degree of percolation is used to quantify the distribution of MWCNTs among the phases, and is then used in a rule-of-mixtures formulation for the storage modulus, , and the loss modulus, , to quantify the properties of the continuous phase consisting of percolated MWCNTs and the continuous PS phase reinforced by non-interacting MWCNTs from the experimental melt rheology data. The properties of the continuous phase of percolated MWCNTs are indicative of a scaffold-like microstructure exhibiting an elastic behavior with a complex modulus of 360 kPa at lower frequencies and viscoplastic behavior with a complex viscosity of 6 kPa s rad−1 at higher frequencies, most likely due to a stick–slip friction mechanism at the interface of the percolated MWCNTs. Additional evidence of this microstructure was obtained via scanning electron microscopy. This research has important implications in providing a new methodology based on the electrical and rheological properties of the polymer nanocomposite for quantifying the continuous phase formed by the percolation of new functionalized nanostructures being developed for: (a) controlling the percolation of the nanostructures through self-assembly, (b) enhancing their interaction with the continuous reinforced polymer phase, (c) enhancing the cohesion between nanostructures.}, number={50}, journal={Nanotechnology}, publisher={IOP Publishing}, author={Kota, Arun K and Cipriano, Bani H and Powell, Dan and Raghavan, Srinivasa R and Bruck, Hugh A}, year={2007}, month={Nov}, pages={505705} }
 @article{kota_anand_ramakrishnan_regel_wilcox_2006, title={Influence of oxygen, hydrogen, helium, argon and vacuum on the surface behavior of molten InSb, other semiconductors, and metals on silica}, volume={290}, ISSN={0022-0248}, url={http://dx.doi.org/10.1016/j.jcrysgro.2006.01.044}, DOI={10.1016/j.jcrysgro.2006.01.044}, abstractNote={Sessile drop experiments were performed on molten indium antimonide on clean quartz (fused silica) surfaces. A cell was constructed through which argon, helium, oxygen, hydrogen or a mixture of these was flowed at 600 °C. Some of the InSb was doped with 0.1% Ga. The surface tension σ of oxide-free molten InSb was smaller in Ar than in He, may have increased with increasing O2 in the gas, and was not influenced by Ga or H2. The contact angle θ on silica was higher in the presence of Ar, was lowered by O2, and was not influenced by H2 or Ga. The work of adhesion W and the surface energy σsv of the silica were higher in He than in Ar. The surface remained free of solid oxide only in flowing gas containing ⩽0.8 ppm O2. This behavior is attributed to reaction of O2 at the surface of the melt to form In2O gas. When solid oxide formed on Ga-doped material, it was strongly enriched in Ga, with the Ga/In ratio increasing with the concentration of O2 in the gas. Examination of published sessile-drop results for liquid metals and semiconductors on silica revealed that W and σsv were highest for reactive melts, in which SiO2 dissolves. For non-reactive melts, W and σsv were lower and θ higher in a gas than in a vacuum, regardless of whether the experiments had been carried out in sealed ampoules, a flowing gas, or dynamic vacuum. The implication is that the surface of silica was different in a vacuum than in a gas at ∼1 bar.}, number={2}, journal={Journal of Crystal Growth}, publisher={Elsevier BV}, author={Kota, Arun K. and Anand, Gaurav and Ramakrishnan, Suresh and Regel, Liya L. and Wilcox, William R.}, year={2006}, month={May}, pages={319–333} }
 @article{gallant_bruck_kota_2004, title={Fabrication of Particle-Reinforced Polymers with Continuous Gradient Architectures Using Twin Screw Extrusion Process}, volume={38}, ISSN={0021-9983 1530-793X}, url={http://dx.doi.org/10.1177/0021998304048414}, DOI={10.1177/0021998304048414}, abstractNote={ The operation of the twin screw extrusion (TSE) process under transient conditions is investigated for the manufacture of particle-reinforced polymers with continuous gradient architectures. Mixing models of the residence time distribution (RTD) and residence volume distribution (RVD) are used to characterize the TSE process. By convolving the mixing models with the transient input conditions, a new convolution process model has been developed to predict the gradient architectures that evolve within the extrudate. In situ optical contrast measurements and a posteriori measurements of optical contrast, density, and solids loading are used to verify the convolution process model for a step change in the input conditions. }, number={21}, journal={Journal of Composite Materials}, publisher={SAGE Publications}, author={Gallant, Frederick M. and Bruck, Hugh A. and Kota, Arun K.}, year={2004}, month={Nov}, pages={1873–1893} }