Diamond, Dermot

Florea, Larisa

Tudor, Alexandru

Name not available

Multi-responsive Semi-Interpetrating Network Hydrogels Introduction Alexandru Tudor, Larisa Florea*, Dermot Diamond Insight Centre for Data Analytics, National Centre for Sensor Research, Dublin City University, Dublin, Ireland Semi-interpenetrating networks (sIPNs) are a type of polymer networks in which one polymer is crosslinked in the presence of a linear polymer solution. The materials used in this case are the poly(ionic liquid) (PIL), tributylhexyl phosphonium 3-sulfopropyl acrylate (PSPA) as the crosslinked matrix while the linear polymer is a poly(N-isopropylacrylamide-co-spiropyran-co-acrylic acid) p(NiPAAm-BSP-AA) copolymer, which is both thermo- and photo- responsive. The research described herein focuses on determining the influence of temperature, white light and salt concentration on the are of the sIPN hydrogels swollen in deionized water (DI water). The area shrinkage was calculated using the following formula: %s = (Ai - Af)/Ai x 100, where Ai is the initial area of the swollen hydrogel and Af  is the final area of the hydrogel after the application of  the stimulus.   Conclusions  Acknowledgements  The authors are grateful for financial support from the Marie Curie Initial Training Network funded by the EC FP7 People Programme OrgBIO (Marie Curie ITN, GA607896) and Science Foundation Ireland (SFI) under the Insight Centre for Data Analytics initiative, Grant Number SFI/12/RC/2289. A functional polymer has been synthesized by copolymerizing NiPAAm with BSP and AA. This copolymer has been embedded into a PSPA matrix, creating a series of sIPNs that exhibited various degrees of shrinking when exposed to white light, salt concentration, and an increase in temperature, respectively.  White-light Induced Shrinking Temperature Induced Shrinking sIPN Synthesis    White light PBPO ACN/H2O PPG 800 p(NiPAAm-BSP-AA) White light PBPO THF  + + NiPAAm AA BSP p(NiPAAm-BSP-AA) PSPA sIPN   The sIPN hydrogels were hydrated in deionized water and NaCl solutions of different concentrations, 0.5%, 1% and 5%  (wt%), respectively, followed by exposure to an illumination level of 200 kLux. The resulting shrinking in area is shown above.  Salt Concentration Induced Shrinking The crosslinked PIL hydrogel shrank by ~16% in area when its hydration medium was changed from DI water to 1 wt% NaCl solution. The salt concentration induced shrinking is a reversible process. Changing the hydration medium back to DI water causes the gel to return to its initial size.    The increase in temperature from 20 °C to 70 °C causes the crosslinked PIL hydrogel to shrink by ~53% in area. As in the case of salt concentration, the temperature induced shrinking is a reversible, repeatable process.    68101214161810 20 30 40 50 60 70 80Area (mm²) Temperature (°C) PILc in DI WaterPILc in NaCl 0.5 wt% solutionThe presence of a chaotropic salt in the hydration solution of the crosslinked hydrogels inhibits the temperature-induced shrinking. This behavior is exemplified on the crosslinked PIL.  In the dark at 20 ºC  In the dark at 36 ºC  Under white light at 20 ºC  Under white light at 36 ºC  t = 0 min 1 wt% NaCl t = 16 min DI Water 1 cm 1 cm T = 20 ºC T ºC T = 70 ºC 1 cm 1 cm 

Multi-responsive semi-interpenetrating network hydrogels

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http://doras.dcu.ie/20726/1/Poster_AT_OrgBIO_Thessaloniki.pdf

Multi-responsive semi-interpenetrating network hydrogels

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