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测定了25℃时硅胶自水溶液中吸附五种聚乙二醇(PEG)、一种聚丙二醇(PPG)和三种环氧乙烷(EO)-环氧丙烷(PO)嵌段共聚物的吸附等温线。除PPG的等温线为S型外,其余的均为Langmuir型的。计算结果表明,对于PEG系列和EO-PO嵌段共聚物系列都可得到极限吸附时的分子面积(A)与分子中所含EO数(n_(EO))的关系为不通过原点的曲线。当PEG分子量大到一定程度后,此A-n_(EO)关系即成近似于通过原点的直线。根据所得结果的分析,以及考虑了吸附水的影响,初步可得出分子是以平躺的方式被吸附的结论。文中还计算了吸附直由能,并对计算结果作了初步的解释。
The adsorption of five kinds of polyethylene glycol (PEG), one kind of polypropylene glycol (PPG) and three kinds of ethylene oxide (EO) -propylene oxide (PO) block copolymer onto silica gel at 25 ℃ was measured. Isotherm. Except that the isotherm of PPG is S type, the rest are Langmuir type. The calculated results show that the relationship between molecular area (A) and the number of EO contained in the molecule (n EO) is the curve that does not pass through the origin for both the PEG series and the EO-PO block copolymer series. When the PEG molecular weight to a certain extent, this A-n_ (EO) relationship that is similar to the straight line through the origin. According to the analysis of the obtained results and considering the influence of the adsorbed water, it can be concluded initially that the molecules are adsorbed in a lying manner. In this paper, the adsorption energy is also calculated, and the calculation results are preliminarily explained.