02590nas a2200229   4500008004100000022001400041245007700055210006900132260007100201300001400272490000700286520177200293100001702065700002502082700001802107700002202125700002402147700003202171700002502203700002702228856010502255       2010                        eng d  a0024-929700aVolume transition of PNIPAM in a nonionic surfactant hexagonal mesophase0 aVolume transition of PNIPAM in a nonionic surfactant hexagonal m  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a4782-47900 v433 a<p>We investigate the volume transition of a thermoresponsive polymer, poly(N-isopropylacrylamide), PNIPAM, in the presence of an aqueous solution of nonionic surfactant, C(12)E(9). We combine turbidimetry with optical microscopy, NMR, and SAXS to follow the volume transition of the PNIPAM and the H(1)-isotropic transition of the surfactant/water system. Nonionic surfactants such as C(12)E(9) are known to interact weakly with PNIPAM. Accordingly, we show that there is only a small change in the volume transition temperature for the PNIPAM in isotropic micellar solutions of C(12)E(9), even for relatively high concentrations of C(12)E(9). Interestingly, once the surfactant forms an H(1) phase, there is a dramatic decrease in the coil globule transition onset temperature. We believe that this behavior results from a competition between C(12)E(9) in the H(1) phase, and PNIPAM to associate with water. When PNIPAM in the H(1) phase is cooled to low enough temperatures so as to be in the coil state, it locally disturbs the hexagonal phase ordering. Thus, we show that for PNIPAM in a weakly interacting surfactant matrix, it is the phase behavior of the matrix rather than the matrix chemistry that governs the coil globule transition. Finally, we show that in a PNIPAM copolymer with a higher LCST we observe an interesting sequence of transitions in the surfactant phase: on cooling from a high temperature free-blowing turbid globular state (similar to 75 degrees C), we enter a free-flowing translucent coil phase (similar to 47 degrees C), then a turbid gel (similar to 25 degrees C) where the copolymer is collapsed in the HI phase, and finally a low-temperature clear gel (similar to 5 degrees C) where the copolymer is in the expanded coil state.</p>1 aJijo, V., J.1 aSharma, Kamendra, P.1 aMathew, Renny1 aKamble, Samruddhi1 aRajamohanan, P., R.1 aAjithkumar, Thalasseril, G.1 aBadiger, Manohar, V.1 aKumaraswamy, Guruswamy  uhttp://library.ncl.res.in/content/volume-transition-pnipam-nonionic-surfactant-hexagonal-mesophase-002117nas a2200181   4500008004100000245012900041210006900170260000800239300001600247490000600263520143700269100001801706700002001724700002001744700001701764700002501781856012901806       2019                        eng d00aVivo wound healing performance of halloysite clay and gentamicin-incorporated cellulose ether-PVA electrospun nanofiber mats0 aVivo wound healing performance of halloysite clay and gentamicin  cSEP  a4324–43340 v23 a<p>Wound healing is a dynamic and complex process that requires a suitable environment to enhance the rapid healing process. In this context, fabrications of nanofibrous materials with antibiotic and antibacterial properties are becoming extremely important. In this present work, we report on the fabrication and characterization of electro-spun cellulose ether-PVA nanofiber mats loaded with halloysite clay (HNT) and gentamicin sulfate (GS) for faster wound healing applications. The morphology of nanofiber mats was examined by SEM and TEM. The average diameter of the nanofiber mats were in the range of 325 ± 30 nm. The physicochemical characterizations were done by FT-IR and XRD, which reveal the presence of HNT and GS into the nanofibers. The incorporation of halloysite gave good mechanical strength to the nanofiber mats. Swelling studies indicated the hydrophilicity of the mats. In vitro studies revealed that HNTs are nontoxic to L929 fibroblast cells and also promote cell growth and proliferation. The antibacterial property of HNT was also studied. The slow release of GS from the nanofiber mats was observed for a period of 18 days. The in vivo wound healing studies on the wistar rats for 21 days revealed the wound healing faster within 2 weeks by the incorporation of HNT and GS into the nanofiber mats and hence these nanofiber mats show great potential in acute and chronic wound healing applications.</p>
1 aWali, Ashwini1 aGorain, Mahadeo1 aInamdar, Satish1 aKundu, Gopal1 aBadiger, Manohar, V.  uhttp://library.ncl.res.in/content/vivo-wound-healing-performance-halloysite-clay-and-gentamicin-incorporated-cellulose-ether