PAMPS/SiO_2杂化水凝胶的合成及电场敏感性研究

SYNTHESIS AND ELECTRIC-SENSITIVE PROPERTIES OF PAMPS/SiO_2 HYBRID HYDROGELS

以2-丙烯酰胺-2-甲基丙磺酸(AMPS)为有机原料,正硅酸乙酯(TEOS)为无机原料,过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,通过原位-凝胶水溶液聚合法合成了一系列不同二氧化硅含量和不同聚离子浓度的聚(2-丙烯酰胺-2-甲基丙磺酸)/二氧化硅杂化电场敏感性水凝胶.通过扫描电子显微镜(SEM)表征凝胶的结构,研究水凝胶在去离子水以及氯化钠溶液中的溶胀和消溶胀行为.结果表明,系列凝胶的平衡溶胀度介于224.9至325.6之间,复合凝胶的溶胀速率随TEOS用量的增加而降低;除理想杂化凝胶外,随着聚离子浓度的升高,凝胶在氯化钠溶液中的消溶胀速率逐渐减小.对凝胶的电场敏感性研究表明,当聚离子浓度大于氯化钠溶液浓度时,凝胶进一步溶胀,反之则消溶胀,其中杂化凝胶的再溶胀性能减弱,而消溶胀行为变得更为明显.同时制得的理想杂化凝胶,较纯有机凝胶具有更为理想的力学性能,最大抗压缩强度可达23.4 MPa.

A series of electric-sensitive hydrogels were prepared by in-site gel polymerization with 2- acrylamido-2-methyl propyl sulfonic acid （AMPS） as organic monomer and ethyl orthosilieate （TEOS） as inorganic material,using N,N＇-methylene bisaerylamide as crosslinking agent and potassium peroxydisulfate as initiator,respectively. The structure of the hydrogels was characterizated by scanning electrical microscopy （SEM）. The swelling and deswelling properties of hydrogels in deionized water and in NaC1 solution were studied in detail, showing that the equilibrium swelling ratio of the hydrogels ranged from 224.9 to 325.6. And the swelling rate of the composite hydrogels decreased with the increasing content of TEOS, in addition, the deswelling speed of the hydrogel decreased with the increasing concentration of polyion in interior of the hydrogels, except for the ideal hybrid hydrogels. Moreover, the electric sensitivity of the hydrogels was considered. The result revealed that the hydrogels swelled at high concentration of NaC1 in solution （higher than that of polyion in interior hydrogels） , but deswelled at low concentration. As for ideal hybrid gel, the reswelling ratios decreased, and the deswelling property was more obvious. Furthermore, the ideal hybrid hydrogels had more ideal mechanical properties than organic gels, and the maximum compressive strength of the hydrogels was about 23.4 MPa.