Preparation of double-layered nanosheets containing pH-responsive polymer networks in the interlayers and their conversion into single-layered nanosheets through the cleavage of cross-linking points
Preparation of double-layered nanosheets containing pH-responsive polymer networks in the interlayers and their conversion into single-layered nanosheets through the cleavage of cross-linking points
复制标题
夹层中含有 pH 响应聚合物网络的双层纳米片的制备及其通过交联点裂解转化为单层纳米片
DOI：
10.1039/d1dt04355b
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发表时间：
2022
影响因子：
4
通讯作者：
Sugahara Yoshiyuki
中科院分区：
文献类型：
--
作者：
Kamibe Takuma;Regis Guegan;Kunitake Masashi;Tsukahara Takehiko;Idota Naokazu;Sugahara Yoshiyuki
在K4Nb6O17·3H2O的水合中间层（中间层I）表面通过表面引发原子转移自由基聚合，将n-异丙基丙烯酰胺与酸降解交联剂共聚，然后在无水中间层（中间层II）中引入四正丁基铵（TBA）离子进行剥离，制备了两层铌酸盐之间含有ph可切割聚合物网络的双层纳米片。利用傅里叶变换红外光谱（FTIR）和热重（TG）分析结果表明，聚合物网络存在，经TBA离子剥离后，原子力显微镜（AFM）观察到纳米片的厚度为10.8±1.6 nm。通过降低pH，纳米片的厚度降低到6.1±0.9 nm，质子核磁共振（1H NMR）和紫外-可见光谱分析表明，交联剂继续降解，表明交联点的断裂导致双层纳米片转变为单层纳米片。
Double-layered nanosheets containing pH-cleavable polymer networks between two niobate layers were prepared by copolymerization of N-isopropylacrylamide and an acid-degradable crosslinker via surface-initiated atom transfer radical polymerization on the surface of hydrated interlayers (interlayer I) of K4Nb6O17·3H2O and subsequent exfoliation by the introduction of tetra-n-butylammonium (TBA) ions into anhydrous interlayers (interlayer II). Moreover, the double-layered nanosheets were converted into single-layered nanosheets by the cleavage of cross-linking points in polymer networks by lowering pH. Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG) results showed that polymer networks were present, and nanosheets with a thickness of 10.8 ± 1.6 nm were observed by using an atomic force microscope (AFM) after exfoliation using TBA ions. The thickness of the nanosheets was decreased to 6.1 ± 0.9 nm by lowering the pH, and proton nuclear magnetic resonance (1H NMR) and UV-vis spectroscopy showed that the degradation of the cross-linkers proceeded, suggesting that the cleavage of the cross-linking points led to the conversion of double-layered nanosheets into single-layered nanosheets.