Cao Meng, Wu Lili, Zhang Guixia, Yang Ying, Chen Wei, Li Qiu, Tang Pei, Chen Wanyu
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Polymers (Basel). 2022 May 20;14(10):2081. doi: 10.3390/polym14102081.
Chloride ions in the seaside environment can corrode the steel reinforcement in concrete, which greatly endangers the safety of seaside structures. As an excellent adsorption material, hydrogel is widely used in the field of water treatment but is rarely used in cementitious materials. In this study, a polyacrylamide-chitosan hydrogel (PAMC) was prepared with N,N-methylenebisacrylamide as the cross-linking agent and acrylamide as the monomer. The prepared PAMC gel could effectively adsorb chloride ions in simulated seawater and simulated sea sand environments, and the maximum adsorption capacity of chloride ions by PAMC-1 (prepared from 2.5 g acrylamide and 1% content of N,N-methylenebisacrylamide relative to acrylamide) gels in simulated seawater was 55.53 mg/g. The adsorption behavior of the PAMC gels in solution fit the Langmuir isotherm model. The composition and morphology of the PAMC gel were characterized, and the responsiveness of the PAMC gel to the environment was studied. The results showed that the PAMC gels adsorbed better in alkaline environments and thus could be used in alkaline cement-based environments. The mortar sample containing the PAMC-1 gel had higher resistance to chloride ion penetration, and the chloride ion content at 7.5-10mm from the surface of the sample cured for 28 days was reduced by 41.4% compared to the samples without the gel.
滨海环境中的氯离子会腐蚀混凝土中的钢筋，这对滨海建筑结构的安全构成了极大威胁。水凝胶作为一种优良的吸附材料，在水处理领域得到了广泛应用，但在胶凝材料中却很少使用。本研究以N,N-亚甲基双丙烯酰胺为交联剂、丙烯酰胺为单体，制备了聚丙烯酰胺-壳聚糖水凝胶（PAMC）。制备的PAMC凝胶能有效吸附模拟海水和模拟海砂环境中的氯离子，PAMC-1（由2.5 g丙烯酰胺和相对于丙烯酰胺1%含量的N,N-亚甲基双丙烯酰胺制备）凝胶在模拟海水中对氯离子的最大吸附量为55.53 mg/g。PAMC凝胶在溶液中的吸附行为符合Langmuir等温线模型。对PAMC凝胶的组成和形貌进行了表征，并研究了PAMC凝胶对环境的响应性。结果表明，PAMC凝胶在碱性环境中吸附效果较好，因此可用于碱性水泥基环境。含有PAMC-1凝胶的砂浆试样对氯离子渗透的抗性更高，与不含凝胶的试样相比，养护28天的试样距表面7.5 - 10mm处的氯离子含量降低了41.4%。
