@article{joshipura_nguyen_quinn_yang_morales_santiso_daeneke_truong_dickey_2023, title={An atomically smooth container: Can the native oxide promote supercooling of liquid gallium?}, volume={26}, ISSN={["2589-0042"]}, url={https://doi.org/10.1016/j.isci.2023.106493}, DOI={10.1016/j.isci.2023.106493}, abstractNote={Metals tend to supercool—that is, they freeze at temperatures below their melting points. In general, supercooling is less favorable when liquids are in contact with nucleation sites such as rough surfaces. Interestingly, bulk gallium (Ga) can significantly supercool, even when it is in contact with heterogeneous surfaces that could provide nucleation sites. We hypothesized that the native oxide on Ga provides an atomically smooth interface that prevents Ga from directly contacting surfaces, and thereby promotes supercooling. Although many metals form surface oxides, Ga is a convenient metal for studying supercooling because its melting point of 29.8°C is near room temperature. Using differential scanning calorimetry (DSC), we show that freezing of Ga with the oxide occurs at a lower temperature (−15.6 ± 3.5°C) than without the oxide (6.9 ± 2.0°C when the oxide is removed by HCl). We also demonstrate that the oxide enhances supercooling via macroscopic observations of freezing. These findings explain why Ga supercools and have implications for emerging applications of Ga that rely on it staying in the liquid state.}, number={4}, journal={ISCIENCE}, author={Joshipura, Ishan D. and Nguyen, Chung Kim and Quinn, Colette and Yang, Jiayi and Morales, Daniel H. and Santiso, Erik and Daeneke, Torben and Truong, Vi Khanh and Dickey, Michael D.}, year={2023}, month={Apr} } @article{farrell_jacob_truong_elbourne_kong_hsiao_dickey_tabor_2023, title={Compositional Design of Surface Oxides in Gallium-Indium Alloys}, volume={1}, ISSN={["1520-5002"]}, url={https://doi.org/10.1021/acs.chemmater.2c02696}, DOI={10.1021/acs.chemmater.2c02696}, abstractNote={Room-temperature liquid metal alloys encompass a highly versatile family of materials possessing a unique set of chemical, electronic, biological, and mechanical properties. The surface oxide of liquid metals has a direct influence on these properties and is often composed of one of the major alloy components (i.e., gallium or indium). However, this is not a foregone conclusion, as the identity of the surface oxide can be altered by the addition of minority elements into the liquid metal. Through judicious choice of a minority alloying metal, the composition of the oxide and therefore the resulting molten alloy’s properties are significantly modified. We demonstrate this by adding a small amount (∼5%) of several thermodynamically favorable alloying elements (X = Zn, Mg, Al) to eutectic gallium indium (EGaIn), resulting in a new class of alloys with designed surface oxide compositions that we term XGaIn. Using both STEM-EDS and XPS, XGaIn alloys are shown to form oxide layers enriched in the lowest-redox element as expected based on the thermodynamics of the alloy system. This approach is shown to be generalizable across both Ga and non-Ga-based liquid metal alloy compositions. XGaIn alloys with added Zn and Mg are shown to have strong antimicrobial activity, which has exciting implications for the development of flexible electronic medical devices and sensors.}, journal={CHEMISTRY OF MATERIALS}, author={Farrell, Zachary J. and Jacob, Alan R. and Truong, Vi Khanh and Elbourne, Aaron and Kong, Wilson and Hsiao, Lilian and Dickey, Michael D. and Tabor, Christopher}, year={2023}, month={Jan} } @article{kwon_cheeseman_frias‐de‐diego_hong_yang_jung_yin_murdoch_scholle_crook_et al._2021, title={A Liquid Metal Mediated Metallic Coating for Antimicrobial and Antiviral Fabrics}, volume={33}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.202104298}, DOI={10.1002/adma.202104298}, abstractNote={Fabrics are widely used in hospitals and many other settings for bedding, clothing, and face masks; however, microbial pathogens can survive on surfaces for a long time, leading to microbial transmission. Coatings of metallic particles on fabrics have been widely used to eradicate pathogens. However, current metal particle coating technologies encounter numerous issues such as nonuniformity, processing complexity, and poor adhesion. To overcome these issues, an easy‐to‐control and straightforward method is reported to coat a wide range of fabrics by using gallium liquid metal (LM) particles to facilitate the deposition of liquid metal copper alloy (LMCu) particles. Gallium particles coated on the fabric provide nucleation sites for forming LMCu particles at room temperature via galvanic replacement of Cu2+ ions. The LM helps promote strong adhesion of the particles to the fabric. The presence of the LMCu particles can eradicate over 99% of pathogens (including bacteria, fungi, and viruses) within 5 min, which is significantly more effective than control samples coated with only Cu. The coating remains effective over multiple usages and against contaminated droplets and aerosols, such as those encountered in facemasks. This facile coating method is promising for generating robust antibacterial, antifungal, and antiviral fabrics and surfaces.}, number={45}, journal={Advanced Materials}, publisher={Wiley}, author={Kwon, Ki Yoon and Cheeseman, Samuel and Frias‐De‐Diego, Alba and Hong, Haeleen and Yang, Jiayi and Jung, Woojin and Yin, Hong and Murdoch, Billy J. and Scholle, Frank and Crook, Nathan and et al.}, year={2021}, month={Sep}, pages={2104298} } @article{chapman_orrell-trigg_kwoon_truong_cozzolino_2021, title={A high-throughput and machine learning resistance monitoring system to determine the point of resistance for Escherichia coli with tetracycline: Combining UV-visible spectrophotometry with principal component analysis}, volume={118}, ISSN={["1097-0290"]}, DOI={10.1002/bit.27664}, abstractNote={UV‐visible spectroscopy (UV‐Vis) is routinely used in microbiology as a tool to check the optical density (OD) pertaining to the growth stages of microbial cultures at the single wavelength of 600 nm, better known as the OD600. Typically, modern UV‐Vis spectrophotometers can scan in the region of approximately 200–1000 nm in the electromagnetic spectrum, where users do not extend the use of the instrument's full capability in a laboratory. In this study, the full potential of UV‐Vis spectrophotometry (multiwavelength collection) was used to examine bacterial growth phases when treated with antibiotics showcasing the ability to understand the point of resistance when an antibiotic is introduced into the media and therefore understand the biochemical changes of the infectious pathogens. A multiplate reader demonstrated a high throughput experiment (96 samples) to understand the growth of Escherichia coli when varied concentrations of the antibiotic tetracycline was added into the well plates. Principal component analysis (PCA) and partial least squares discriminant analysis were then used as the data mining techniques to interpret the UV‐Vis spectral data and generate machine learning “proof of principle” for the UV‐Vis spectrophotometer plate reader. Results from this study showed that the PCA analysis provides an accurate yet simple visual classification and the recognition of E. coli samples belonging to each treatment. These data show significant advantages when compared to the traditional OD600 method where we can now understand biochemical changes in the system rather than a mere optical density measurement. Due to the unique experimental setup and procedure that involves indirect use of antibiotics, the same test could be used for obtaining practical information on the type, resistance, and dose of antibiotic necessary to establish the optimum diagnosis, treatment, and decontamination strategies for pathogenic and antibiotic resistant species.}, number={4}, journal={BIOTECHNOLOGY AND BIOENGINEERING}, author={Chapman, James and Orrell-Trigg, Rebecca and Kwoon, Ki Y. and Truong, Vi K. and Cozzolino, Daniel}, year={2021}, month={Apr}, pages={1511–1519} } @misc{shaw_kuriakose_cheeseman_dickey_genzer_christofferson_crawford_mcconville_chapman_truong_et al._2021, title={Antipathogenic properties and applications of low-dimensional materials}, volume={12}, ISSN={["2041-1723"]}, url={https://doi.org/10.1038/s41467-021-23278-7}, DOI={10.1038/s41467-021-23278-7}, abstractNote={A major health concern of the 21st century is the rise of multi-drug resistant pathogenic microbial species. Recent technological advancements have led to considerable opportunities for low-dimensional materials (LDMs) as potential next-generation antimicrobials. LDMs have demonstrated antimicrobial behaviour towards a variety of pathogenic bacterial and fungal cells, due to their unique physicochemical properties. This review provides a critical assessment of current LDMs that have exhibited antimicrobial behaviour and their mechanism of action. Future design considerations and constraints in deploying LDMs for antimicrobial applications are discussed. It is envisioned that this review will guide future design parameters for LDM-based antimicrobial applications.}, number={1}, journal={NATURE COMMUNICATIONS}, author={Shaw, Z. L. and Kuriakose, Sruthi and Cheeseman, Samuel and Dickey, Michael D. and Genzer, Jan and Christofferson, Andrew J. and Crawford, Russell J. and McConville, Chris F. and Chapman, James and Truong, Vi Khanh and et al.}, year={2021}, month={Jun} } @article{ko_truong_woo_dickey_hsiao_genzer_2021, title={Counterpropagating Gradients of Antibacterial and Antifouling Polymer Brushes}, volume={12}, ISSN={["1526-4602"]}, url={https://doi.org/10.1021/acs.biomac.1c01386}, DOI={10.1021/acs.biomac.1c01386}, abstractNote={We report on the formation of counterpropagating density gradients in poly([2-dimethylaminoethyl] methacrylate) (PDMAEMA) brushes featuring spatially varying quaternized and betainized units. Starting with PDMAEMA brushes with constant grafting density and degree of polymerization, we first generate a density gradient of quaternized units by directional vapor reaction involving methyl iodide. The unreacted DMAEMA units are then betainized through gaseous-phase betainization with 1,3-propanesultone. The gas reaction of PDMAEMA with 1,3-propanesultone eliminates the formation of byproducts present during the liquid-phase modification. We use the counterpropagating density gradients of quaternized and betainized PDMAEMA brushes in antibacterial and antifouling studies. Completely quaternized and betainized brushes exhibit antibacterial and antifouling behaviors. Samples containing 12% of quaternized and 85% of betainized units act simultaneously as antibacterial and antifouling surfaces.}, journal={BIOMACROMOLECULES}, publisher={American Chemical Society (ACS)}, author={Ko, Yeongun and Truong, Vi Khanh and Woo, Sun Young and Dickey, Michael D. and Hsiao, Lilian and Genzer, Jan}, year={2021}, month={Dec} } @misc{kwon_truong_krisnadi_im_ma_mehrabian_kim_dickey_2021, title={Surface Modification of Gallium-Based Liquid Metals: Mechanisms and Applications in Biomedical Sensors and Soft Actuators}, volume={3}, ISSN={["2640-4567"]}, url={http://dx.doi.org/10.1002/aisy.202000159}, DOI={10.1002/aisy.202000159}, abstractNote={This review focuses on surface modifications to gallium‐based liquid metals (LMs), which are stretchable conductors with metallic conductivity and nearly unlimited extensibility due to their liquid nature. Despite the enormous surface tension of LM, it can be patterned into nonspherical shapes, such as wires, due to the presence of a native oxide shell. Incorporating inherently soft LM into elastomeric devices offers comfort, mechanical compliance, and stretchability. The thin oxide layer also enables the formation of stable liquid colloids and LM micro/nanosized droplets that do not coalesce easily. The oxide layer can also be exfoliated and chemically modified into semiconductor 2D materials to create and deposit atomically thin materials at room temperature. Thus, the interface and its manipulation are important. This review summarizes physical and chemical methods of modifying the surface of LM to tune its properties. The surface modification of LM provides unique applications, including use in soft biomedical sensors and actuators with mechanical properties similar to human tissue.}, number={3}, journal={ADVANCED INTELLIGENT SYSTEMS}, author={Kwon, Ki Yoon and Truong, Vi Khanh and Krisnadi, Febby and Im, Sooik and Ma, Jinwoo and Mehrabian, Nazgol and Kim, Tae-il and Dickey, Michael D.}, year={2021}, month={Mar} } @article{gangadoo_elbourne_medvedev_cozzolino_truong_crawford_wang_truong_chapman_2020, title={Facile Route of Fabricating Long-Term Microbicidal Silver Nanoparticle Clusters against Shiga Toxin-Producing Escherichia coli O157:H7 and Candida auris}, volume={10}, ISSN={["2079-6412"]}, DOI={10.3390/coatings10010028}, abstractNote={Microbial contamination remains a significant issue for many industrial, commercial, and medical applications. For instance, microbial surface contamination is detrimental to numerous aspects of food production, infection transfer, and even marine applications. As such, intense scientific interest has focused on improving the antimicrobial properties of surface coatings via both chemical and physical routes. However, there is a lack of synthetic coatings that possess long-term microbiocidal performance. In this study, silver nanoparticle cluster coatings were developed on copper surfaces via an ion-exchange and reduction reaction, followed by a silanization step. The durability of the microbiocidal activity for these develped surfaces was tested against pathogenic bacterial and fungal species, specifically Escherichia coli O157:H7 and Candida auris, over periods of 1- and 7-days. It was observed that more than 90% of E. coli and C. auris were found to be non-viable following the extended exposure times. This facile material fabrication presents as a new surface design for the production of durable microbicidal coatings which can be applied to numerous applications.}, number={1}, journal={COATINGS}, author={Gangadoo, Sheeana and Elbourne, Aaron and Medvedev, Alexander E. and Cozzolino, Daniel and Truong, Yen B. and Crawford, Russell J. and Wang, Peng-Yuan and Truong, Vi Khanh and Chapman, James}, year={2020}, month={Jan} }