Conformation and Kinetics in Polyelectrolyte Adsorption

研究了聚电解质在固/液和液/液界面吸附的Schlenoff动力学和等温线。用表面附着氧化还原基团衍生的金属表面将被用来精确地控制表面电荷，以便将聚合物的构象和覆盖范围与表面电荷密度联系起来。这些“智能”氧化还原活性表面将用于确定吸附是否属于热力学或动力学控制。将合成放射性标记的亲水/疏水共聚物，如苯乙烯磺酸盐/丁基苯乙烯，并研究它们在两种不混相液体界面上的吸附。对于吸附的聚电解质，将测量平均线圈半径对盐浓度的依赖关系，并与众所周知的溶液聚电解质尺寸对筛选长度的依赖关系进行比较。产生刷状形态的双嵌段共聚物将被吸附在固体/液体和液体/液体界面上，它们在这两个界面上的表面覆盖率将被比较，并与疏水表面锚定块的迁移率有关。将测量聚电解质对相反电荷凝胶的吸收，以确定带电大分子在零外加电场条件下渗透到带电基质中的程度和动力学。聚电解质的吸附是处理环境用水（饮用水、市政和工业废水等）的关键步骤。本研究将为各种吸附理论提供重要的实验依据。

9414289 Schlenoff Kinetics and isotherms of the adsorption of polyelectrolytes to solid/liquid and liquid/liquid interfaces will be investigated. Metal surfaces derivatized with surface-attached redox groups will be employed to control the surface charge precisely in an effort to relate polymer conformation and coverage to surface charge density. These "smart" redox-active surfaces will be used to ascertain whether adsorption falls under thermodynamic or kinetic control. Radiolabelled hydrophilic/hydrophobic copolymers, such as styrene sulfonate/butyl styrene, will be synthesized and their adsorption at the interface between two immiscible liquids will be studied. For adsorbed polyelectrolytes, the dependence of average coil radius on salt concentration will be measured and compared with the well-known dependence of solution polyelectrolyte dimensions on screening length. Diblock copolymers yielding brush-type morphologies will be adsorbed at the solid/liquid and liquid/liquid interfaces and their surface coverages at these two interfaces will be compared and related to the mobility of the hydrophobic surface-anchoring block. Absorption of a polyelectrolyte into an oppositely- charged gel will be measured to determine the extent and kinetics of penetration of a charged macromolecule into a charged matrix under conditions of zero applied electric field. %%% Adsorption of polyelectrolytes is the critical step in the treatment of water for environmental purposes (drinking water, municipal and industrial effluents, etc.). This research will provide important experiments that can be correlated with various adsorption theories.