CAJ | 학술논문

采用重量分析法对达到溶胀平衡的AA/AMPS、AA/DMAEMA和AMPS/DMAEMA共聚物水凝胶在金属离子溶液中体积收缩变化的动力学过程进行了研究,结果表明:共聚物水凝胶在4种金属离子(Ag~+、Cu~(2+)、Fe~(3+)、Pb~(2+))溶液中均发生体积收缩的响应变化,并且这种变化程度随着金属离子溶液浓度的增加而增加,由"指数衰减第一顺序"函数可以较好地拟合水凝胶体积收缩响应过程的实验数据;在相同的金属离子浓度下,AA/AMPS、AA/DMAEMA和AMPS/DMAEMA水凝胶的平衡体积收缩比(V_∞/V_0)和消溶胀速率常数Kd大小顺序总体一致,分别为Fe~(3+)>Pb~(2+)>Cu~(2+)>Ag~+、Cu~(2+)>Fe~(3+)>Pb~(2+)>Ag~+和Pb~(2+)>Fe~(3+)>Cu~(2+)>Ag~+.通过"孤对电子-空轨道"理论从结构上解释了水凝胶在不同价态重金属溶液中的消溶胀机理;AA/AMPS-Fe~(3+)体系、AA/DMAEMA-Cu~(2+)体系和AMPS/DMAEMA-Pb~(2+)体系体积收缩过程的活化能Ea分别为3.081、1.86、1.917 kJ·moL~(-1).
채용중량분석법대체도용창평형적AA/AMPS、AA/DMAEMA화AMPS/DMAEMA공취물수응효재금속리자용액중체적수축변화적동역학과정진행료연구,결과표명:공취물수응효재4충금속리자(Ag~+、Cu~(2+)、Fe~(3+)、Pb~(2+))용액중균발생체적수축적향응변화,병차저충변화정도수착금속리자용액농도적증가이증가,유"지수쇠감제일순서"함수가이교호지의합수응효체적수축향응과정적실험수거;재상동적금속리자농도하,AA/AMPS、AA/DMAEMA화AMPS/DMAEMA수응효적평형체적수축비(V_∞/V_0)화소용창속솔상수Kd대소순서총체일치,분별위Fe~(3+)>Pb~(2+)>Cu~(2+)>Ag~+、Cu~(2+)>Fe~(3+)>Pb~(2+)>Ag~+화Pb~(2+)>Fe~(3+)>Cu~(2+)>Ag~+.통과"고대전자-공궤도"이론종결구상해석료수응효재불동개태중금속용액중적소용창궤리;AA/AMPS-Fe~(3+)체계、AA/DMAEMA-Cu~(2+)체계화AMPS/DMAEMA-Pb~(2+)체계체적수축과정적활화능Ea분별위3.081、1.86、1.917 kJ·moL~(-1).
De-swelling kinetics of swollen copolymer hydrogels (AA/AMPS, AA/DMAEMA and AMPS/DMAEMA) in metallic ion (Ag~+, Cu~(2+), Fe~(3+) and Pb~(2+)) solutions was investigated with gravimetry.The copolymer hydrogels showed responsive volumetric shrinking behavior in Ag~+, Cu~(2+), Fe~(3+) and Pb~(2+) metallic ion solutions, and the extent of de-swelling increased with ncreasing metallic ion concentration.By using a decaying exponential first-order function, the volume shrinking process of the hydrogels could be well fitted with the correlation coefficient above 0.98.At a fixed concentration of metallic ion, the equilibrium volume shrink ratios (V_∞/V_0) of AA/AMPS, AA/DMAEMA and AMPS/DMAEMA hydrogels were in the order Fe~(3+)>Pb~(2+)>Cu~(2+)>Ag~+,Cu~(2+)>Fe~(3+)>Pb~(2+)>Ag~+, and Pb~(2+)>Fe~(3+)>Cu~(2+)>Ag~+, respectively, and so did the de-swelling rate constant.In addition, a mechanism,"lone pairs of electrons-unoccupied orbitals" was proposed for the gel volume shrinking process, in which the energy of activation values of AA/AMPS-Fe~(3+), AA/DMAEMA-Cu~(2+), and AMPS/DMAEMA-Pb~(2+) system were 3.081, 1.86, and 1.917 kJ·moL~(-1),respectively.