Study on novel exfoliated polyampholyte nanocomposite hydrogels based on acrylic monomers and Mg-Al-Cl layered double hydroxide: Synthesis and characterization
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- 作者：Saadet Ö ; zgü ; mü ; ? ; saadetk@istanbul.edu.tr ; Mehmet Koray Gö ; k ; Ayç ; a Bal ; Gamze Gü ; ç ; lü
- 关键词：Mg&ndash ; Al&ndash ; Cl layered double hydroxides ; Exfoliated polyampholyte nanocomposite hydrogels ; 2-(Diethylamino)ethyl methacrylate ; Acrylic acid ; Polyampholyte nanocomposite hydrogel
- 刊名：Chemical Engineering Journal
- 出版年：2013
- 出版时间：1 May, 2013
- 年：2013
- 卷：223
- 期：Complete
- 页码：277-286
- 全文大小：1612 K
文摘
Novel exfoliated polyampholyte nanocomposite hydrogels (NH-LDHs) based on acrylic acid (AA), 2-(diethylamino) ethyl methacrylate (2-DEAEMA), N,N-methylenebisacrylamide (NMBA) and layered double hydroxide (Mg-Al-Cl LDH) were synthesized using an in situ free radical addition polymerization method in aqueous media. First, Mg-Al-Cl LDH with a highly crystalline structure was prepared and characterized using FTIR, XRD, TGA and SEM analyses. The formation of NH-LDHs was confirmed by FTIR and XRD analyses. The morphological structure and select properties, such as the thermal, swelling and mechanical properties, of the NH-LDHs were also investigated. NH-LDHs have an exfoliated structure and smooth and nonporous surface morphologies. They can also be used as thermally stable nanocomposite hydrogels. The results revealed that adding a small amount of exfoliated Mg-Al-Cl LDH could effectively increase the compressive modulus of the polyampholyte gels. When the Mg-Al-Cl LDH was incorporated into the polyampholyte hydrogel matrix, two synergic effects, additional co-crosslinking and additional hydrophilicity, occur in the swelling behaviors of the gels. All NH-LDHs are sensitive to pH, and they have zwitterion characteristics at pH 5.5. It was concluded that the NH-LDHs synthesized in this study might be used as alternative water absorbents in solutions with different pH. The diffusion of water into the NH-LDHs gel systems in deionized water at room temperature is assumed to be a non-Fickian behavior.