@article{goli_gera_liu_rao_rojas_genzer_2013, title={Generation and Properties of Antibacterial Coatings Based on Electrostatic Attachment of Silver Nanoparticles to Protein-Coated Polypropylene Fibers}, volume={5}, ISSN={["1944-8252"]}, DOI={10.1021/am4011644}, abstractNote={We present a simple method for attaching silver nanoparticles to polypropylene (PP) fibers in a two-step process to impart antibacterial properties. Specifically, PP fibers are pretreated by the adsorption from an aqueous solution of heat-denatured lysozyme (LYS) followed by LYS cross-linking using glutaraldehyde and sodium borohydride. At neutral pH, the surface of the adsorbed LYS layer is enriched with numerous positive charges. Silver nanoparticles (AgNPs) capped with trisodium citrate are subsequently deposited onto the protein-coated PP. Nanoparticle binding is mediated by electrostatic interactions between the positively charged LYS layer and the negatively charged AgNPs. The density of AgNPs deposited on PP depends on the amount of protein adsorbed on the surface. UV-vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy are employed to follow all preparation steps and to characterize the resulting functional surfaces. The antibacterial activity of the modified surfaces is tested against gram negative bacteria Escherichia coli (E. coli). Overall, our results show that PP surfaces coated with AgNPs exhibit excellent antibacterial activity with 100% removal efficiency.}, number={11}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Goli, Kiran K. and Gera, Nimish and Liu, Xiaomeng and Rao, Balaji M. and Rojas, Orlando J. and Genzer, Jan}, year={2013}, month={Jun}, pages={5298–5306} }
 @article{goli_rojas_oezcam_genzer_2012, title={Generation of Functional Coatings on Hydrophobic Surfaces through Deposition of Denatured Proteins Followed by Grafting from Polymerization}, volume={13}, ISSN={["1525-7797"]}, DOI={10.1021/bm300075u}, abstractNote={Hydrophilic coatings were produced on flat hydrophobic substrates featuring n-octadecyltrichlorosilane (ODTS) and synthetic polypropylene (PP) nonwoven surfaces through the adsorption of denatured proteins. Specifically, physisorption from aqueous solutions of α-lactalbumin, lysozyme, fibrinogen, and two soy globulin proteins (glycinin and β-conglycinin) after chemical (urea) and thermal denaturation endowed the hydrophobic surfaces with amino and hydroxyl functionalities, yielding enhanced wettability. Proteins adsorbed strongly onto ODTS and PP through nonspecific interactions. The thickness of adsorbed heat-denatured proteins was adjusted by varying the pH, protein concentration in solution, and adsorption time. In addition, the stability of the immobilized protein layer was improved significantly after interfacial cross-linking with glutaraldehyde in the presence of sodium borohydride. The amino and hydroxyl groups present on the protein-modified surfaces served as reactive sites for the attachment of polymerization initiators from which polymer brushes were grown by surface-initiated atom-transfer radical polymerization of 2-hydroxyethyl methacrylate. Protein denaturation and adsorption as well as the grafting of polymeric brushes were characterized by circular dichroism, ellipsometry, contact angle, and Fourier transform infrared spectroscopy in the attenuated total reflection mode.}, number={5}, journal={BIOMACROMOLECULES}, author={Goli, Kiran K. and Rojas, Orlando J. and Oezcam, A. Evren and Genzer, Jan}, year={2012}, month={May}, pages={1371–1382} }
 @article{liu_goli_genzer_rojas_2011, title={Multilayers of Weak Polyelectrolytes of Low and High Molecular Mass Assembled on Polypropylene and Self-Assembled Hydrophobic Surfaces}, volume={27}, ISSN={["0743-7463"]}, DOI={10.1021/la200349p}, abstractNote={Hydrophobic self-assembled octadecyltrichlorosilane (ODTS), ultrathin films of polypropylene, and ODTS modified with cationic dioctadecyldimethylammonium bromide are employed as substrates for deposition of multilayers of poly(allylamine hydrochloride) and poly(acrylic acid) from aqueous solution. The assembly of highly dissipative polyelectrolyte multilayers (PEMs) is demonstrated by quartz crystal microgravimetry. The initial rate of adsorption is faster and the adsorbed amount larger on the cationic surface, while the detailed structure of the PEMs, as determined by atomic force microscopy imaging, is related primarily to the molecular weight of the adsorbing polymers. A more extensive PEM adsorption on the hydrophobic surfaces takes place with increasing ionic strength of the background electrolyte solution. The water contact angle depends on the type of polymer adsorbed as the outermost layer, indicating that, despite the expected interdiffusion for the different polymer chains, there is a net macromolecular segregation to the free surface. Surface modification with the high molecular weight PEMs produces a more marked reduction of the hydrophilicity of the substrate.}, number={8}, journal={LANGMUIR}, author={Liu, Xiaomeng and Goli, Kiran K. and Genzer, Jan and Rojas, Orlando J.}, year={2011}, month={Apr}, pages={4541–4550} }
 @article{hashem_refaie_goli_smith_hauser_2009, title={Enhancement of Wrinkle Free Properties of Carboxymethylated Cotton Fabric via Ionic Crosslinking with Poly(vinylpyrrolidone)}, volume={39}, ISSN={["1530-8057"]}, DOI={10.1177/1528083709102934}, abstractNote={Incorporation of poly(vinylpyrrolidone) (PVP) in the structure of cotton, carboxymethylated cotton (CMC) or ionically crosslinked cotton fabric induces besides ether crosslinking of cotton cellulose, strong columbic forces and weaker forces such as dipole—dipole, hydrogen bonds, van der Waals, or hydrophobic interactions. The ether bonds are formed in the dry state (i.e., un-swelled state), whereas, the other interactions are formed in wet state (i.e., swelled state) of cotton fabrics. Both interactions greatly enhance wet and dry wrinkle recovery angle of cotton fabric without strength loss. Fixation of PVP onto cotton or CMC fabric was achieved thermally by curing the treated fabric at 140°C for 5 minutes. Higher wet and dry wrinkle recovery angles (WRA and DRA) were obtained with lower molecular weight PVP (3000 Da) compared with higher molecular weight one (8000 Da). The results obtained also show that a balance between WRA, DRA as high as 228° and 225°, respectively, could be obtained without loss in tensile strength and elongation at break by treatment CMC fabric having carboxyl content 115 meq/100 g fabric with 4% PVP then cured at 140°C for 5 minutes. Additionally, treatment of the ionically crosslinked fabric (having 115 meq/100 g fabric carboxyl content and 0.22% nitrogen content) with 4% aqueous PVP enhances the DRA and WRA to reach a value of 289° and 286°, respectively, without any loss in the strength properties of the fabrics. These values of WRA and DRA are much higher than those obtained with cotton fabric (blank) or carboxymethylated cotton. The existence of ionic interaction and ether bonds as well as functional groups introduced into cotton fabrics were confirmed by FTIR spectroscopy.}, number={1}, journal={JOURNAL OF INDUSTRIAL TEXTILES}, author={Hashem, Mohamed and Refaie, Rakia and Goli, Kiral and Smith, Brent and Hauser, Peter}, year={2009}, month={Jul}, pages={57–80} }