私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

Links
Contact Info.
Current Location :> Home > Publications > Text
35. Humidity Effects on the Wetting Characteristics of Poly(N-isopropylacrylacmide) During a Lower Critical Solution Transition
writer:A. Chhabra, R. R. Kanapuram, T. J. Kim, J. Geng, A. K. da Silva, C. W. Bielawski, C. H. Hidrovo,*
keywords:Humidity Effects, Wetting Characteristics, Solution Transition
source:期刊
specific source:Langmuir 2013, 29, 8116-8124
Issue time:2013年

Poly(N-isopropylacrylamide) (PNIPAM) is expected to find utility in tissue engineering and drug delivery, among other biomedical applications. These applications capitalize on the intrinsic lower critical solution temperature (LCST) of the polymer: below the LCST, enthalpic gain from intermolecular hydrogen bonding between PNIPAM and water molecules dominates the solvation; above the LCST, entropic effects resulting from the intramolecular hydrogen bonding between the carboxyl and amide groups of PNIPAM lead to water expulsion. The dependence of the LCST upon the molecular weight, solvent, and solution activity (i.e., solute concentration) has been studied extensively. However, what has not been previously explored is the effect of humidity on the characteristic properties of the polymer. Herein, we show that the relative humidity affects the water adsorption dynamics of PNIPAM as well as the magnitude of the transition that occurs at the LCST of the polymer. In short, the magnitude of the LCST transition decreases with an increasing relative humidity, and the time period over which adsorption occurs decreases with the temperature.