Inorganic Suspensions Using Well-Defined Copolymeric Stabilizers

这项研究是关于低水平的共聚物对水性胶体悬浮液性能的影响的基础研究。系统设计的新型嵌段和接枝共聚物将被合成，每个嵌段的分子量分布窄，并与选定的具有窄尺寸分布的胶体颗粒混合。吸附的共聚物对悬浮液稳定性和性能的影响将通过包括流变学和光散射在内的技术来测量。为了研究颗粒浓度对悬浮体微观结构的临界影响，颗粒浓度将从稀释到高浓度变化。空间稳定性是由共聚物上的水溶尾段提供的，该尾段通过吸附的疏水头部块固定在颗粒上。不溶于水的块体作为锚的有效性将作为化学结构的函数来研究。预计颗粒表面和被吸附的共聚物之间的特定相互作用在水的氢键介质中将特别重要。除了空间位阻稳定机制外，静电稳定对于带电尾段的情况也很重要。要研究的颗粒将是表征良好的无机材料，主要是二氧化硅、三氧化二铝、碳化硅和氮化硅。

This research concerns a fundamental study of the effect of low levels of copolymers on the properties of aqueous colloidal suspensions. Systematically designed, novel, block and graft copolymers with narrow molecular-weight distributions of each block will be synthesized and mixed with selected colloidal particles having narrow-size distributions. The effect of the adsorbed copolymers on the stability and properties of the suspensions will be measured by techniques including rheology and light scattering. The particle concentrations will range from dilute to highly concentrated in order to study the critical effect of particle concentration on suspension microstructure. Steric stability is provided by a water-soluble tail segment on the copolymer that is anchored to the particle by an adsorbed hydrophobic head block. The effectiveness of the water-insoluble block as an anchor will be studied as a function of chemical structure. It is anticipated that specific interactions between the particle surface and the adsorbed copolymer will be of particular importance in aqueous, hydrogen-bonding media. In addition to the steric stabilization mechanism, electrostatic stabilization is also important for the case of charged tail segments. The particles to be studied will be well-characterized inorganic materials, primarily SiO2, Al2O3, SiC, and Si3N4.