摘要
由海藻酸钠(SA)和聚(N 异丙基丙烯酰胺)(PNIPAAm)制得的半互穿网络水凝胶具有温度及pH敏感特性。在酸性(pH=1.3)和弱碱性条件(pH=7.4)下,研究了温度对该凝胶溶胀度的影响,结果表明,该凝胶溶胀度均随着温度的提高而下降,但在pH=1.3时,溶胀度小于PNIPAAm水凝胶的;在pH=7.4时,结果正好相反。在25℃和37℃的条件下,分别考察pH对该凝胶溶胀度的影响,结果表明,在25℃时该凝胶有良好的pH敏感性,而在37℃时,敏感性不明显。同时也发现该凝胶对pH、温度的脉冲刺激有较快的响应性。
A new kind of the semi-IPN hydrogels based on linear sodium alginate (SA) and cross-linked Poly ( N -isopropylacrylamide) (PNIPAAm), which exhibited pH and temperature sensitivities, was synthesized. The swelling behaviors of the semi-IPN hydrogel, which can act as a function of temperature and pH value of the medium, respectively, were investigated in detail. Experimental results show that at acidic condition (pH=1.3) or weak alkaline condition (pH=7.4), the swelling ratios of the semi-IPN hydrogel decreased with increasing temperature, the swelling ratios of the semi-IPN hydrogel at pH 1.3 is lower than those of pure PNIPAAm hydrogels, whereas the swelling ratios of the semi-IPN hydrogel at pH 7.4 is higher than those of pure PNIPAAm hydrogels. The influence of pH on the swelling ratios of semi-IPN hydrogel displays that pH-response of this hydrogels at 25 ℃ is more significant than that of at 37 ℃. Pulsatile stimuli- responsive swelling behaviors of this hydrogels also reveal that the swelling process could be repeatable not only with alternating temperature stimuli but also with pH alternating stimuli. Thus, it is expected that this type of semi-IPN hydrogel could be used in biomedical fields for stimuli-responsive drug delivery systems.
出处
《功能高分子学报》
CAS
CSCD
2004年第1期41-45,共5页
Journal of Functional Polymers
