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采用2H NMR实验结合谱图线型的理论模拟方法研究了两亲性嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯/氘代水/对二甲苯三元体系形成的不同液晶相的结构演化和水分子动力学行为.结果表明,对不同组分浓度的样品,2H谱线型发生明显的变化,对应体系从各向同性相、六角相和层状相间的系列结构转变.通过NMR弛豫模型获得了液晶相结构演化中序参数和分子运动相关时间的变化规律,理论模拟获得的自旋-晶格弛豫时间T1、自旋-自旋弛豫时T2等水分子动力学参数与实验测量结果吻合.结果表明:层状相四极劈裂及序参数随嵌段共聚物或二甲苯含量的增加呈现一个极大值,水分子的T1随着嵌段共聚物浓度增加而明显减小,而T2在六角相到层状相的转变中发生了明显的变化.研究表明,通过理论模拟2H NMR实验获得的谱图线型是研究液晶相结构演化和动力学的有力工具.
The theoretical simulation method of 2H NMR combined with the line graph was used to study the effect of different amphiphilic block copolymer polyoxyethylene-polyoxypropylene-polyoxyethylene / deuterated water / para-xylene ternary systems Structure evolution and water molecular dynamics.The results show that the 2H spectral line changes obviously with the concentration of different components and the corresponding system changes from a series of isotropic, Relaxation model obtained the order of the liquid crystal phase structure evolution and molecular motion related to the law of change, the theoretical simulation obtained spin-lattice relaxation time T1, spin-spin relaxation T2 and other water molecules kinetic parameters The experimental results show that the quadrupole splitting and the order parameter of layered phase exhibit a maximum value with the increase of block copolymer or xylene content, and the T1 of water molecule increases with the increase of block copolymer concentration , And the change of T2 in the hexagonal phase to the lamellar phase changes obviously.The results show that the theoretical linear model obtained by 2H NMR spectroscopy is a powerful tool to study the evolution and kinetics of the liquid crystal phase structure.