Javed Rida, Shah Luqman Ali, Sayed Murtaza, Khan Muhammad Saleem
National Centre of Excellence in Physical Chemistry, University of Peshawar Peshawar 25120 Pakistan
RSC Adv. 2018 Apr 18;8(27):14787-14797. doi: 10.1039/c8ra00578h.
Poly(methacrylic acid) (P(MAA)), poly(acrylamide) (P(AAm)) and poly(3-acrylamidopropyltrimethyl ammonium chloride) (P(APTMACl)) were synthesized as anionic, neutral and cationic hydrogels, respectively. The synthesized hydrogels have the ability to be used as absorbents for the removal of selected heavy metal ions such as Cu, Co, Ni and Zn from aqueous media. Absorption studies revealed that the absorption of metal ions by the hydrogels followed the order Cu > Ni > Co > Zn. For the mechanism of absorption, both Freundlich and Langmuir absorption isotherms were applied. Metal ion entrapped hydrogels were treated using an chemical reduction method in order to convert the metal ions into metal nanoparticles for the synthesis of hybrid hydrogels. The synthesis and morphology were confirmed using FT-IR and SEM, while the absorbed metal amounts were measured using TGA and AAS. The hybrid hydrogels were further used as catalysts for the reduction of macro (methylene blue, methyl orange and congo red) and micro (4-nitrophenol and nitrobenzene) pollutants from the aqueous environment. The catalytic performance and re-usability of the hybrid hydrogels were successfully investigated.
分别合成了聚（甲基丙烯酸）（P（MAA））、聚（丙烯酰胺）（P（AAm））和聚（3-丙烯酰胺基丙基三甲基氯化铵）（P（APTMACl））作为阴离子、中性和阳离子水凝胶。合成的水凝胶有能力用作吸附剂，从水介质中去除选定的重金属离子，如铜、钴、镍和锌。吸附研究表明，水凝胶对金属离子的吸附顺序为铜>镍>钴>锌。对于吸附机理，应用了弗伦德利希和朗缪尔吸附等温线。为了将金属离子转化为金属纳米颗粒以合成杂化水凝胶，采用化学还原法处理金属离子包埋的水凝胶。使用傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）对合成和形态进行了确认，同时使用热重分析（TGA）和原子吸收光谱法（AAS）测量了吸附的金属量。杂化水凝胶进一步用作催化剂，用于还原水环境中的大分子（亚甲基蓝、甲基橙和刚果红）和小分子（4-硝基苯酚和硝基苯）污染物。成功研究了杂化水凝胶的催化性能和可重复使用性。
