The hydrogen\|bond defect of water in PVA hydrogels was studied by Raman spectral analysis. The PVA hydrogels were prepared from PVA of different DP in different concentrations via freeze/thawed method.It was found th...The hydrogen\|bond defect of water in PVA hydrogels was studied by Raman spectral analysis. The PVA hydrogels were prepared from PVA of different DP in different concentrations via freeze/thawed method.It was found that the hydrogen bond defect of water in PVA hydrogels is affected by their crystallinity which was depended on the molecular weight and concentration of PVA and also the number of freeze/thawed cycles.After swelling in water for 24?h,partial VA units were released from the crystalline regions,this means that more `free’ VA units could bond with water in PVA hydrogels,causing the decrease of C value and the increase of N value.展开更多
文摘The hydrogen\|bond defect of water in PVA hydrogels was studied by Raman spectral analysis. The PVA hydrogels were prepared from PVA of different DP in different concentrations via freeze/thawed method.It was found that the hydrogen bond defect of water in PVA hydrogels is affected by their crystallinity which was depended on the molecular weight and concentration of PVA and also the number of freeze/thawed cycles.After swelling in water for 24?h,partial VA units were released from the crystalline regions,this means that more `free’ VA units could bond with water in PVA hydrogels,causing the decrease of C value and the increase of N value.
