Interactions between colloidal particles induced by polymer brushes grafted onto the substrate
Interactions between colloidal particles induced by polymer brushes grafted onto the substrate
复制标题
DOI：
10.1021/jp051403u
复制
发表时间：
2005-09-22
影响因子：
3.3
通讯作者：
Ma, YQ
中科院分区：
文献类型：
--
作者：
Chen, K;Ma, YQ
我们调查的两个胶体粒子之间的相互作用能或沉浸在非吸附聚合物刷接枝到基板上作为一个功能的分离的粒子通过使用自洽场理论计算。取决于胶体的大小和渗透深度，我们证明了存在的排斥能垒的几个k（B）T，这可以通过分离的相互作用能分为三个部分：胶体-聚合物的界面能，熵贡献由于“耗尽区”重叠的胶体颗粒，和熵的弹性能量的接枝链的颗粒的压缩。完全熵起源的排斥屏障的存在可以导致混合物的动力学稳定，而不是耗尽絮凝或相分离。因此，目前的结果可能会建议一种方法，用于控制胶体的自组装行为的目标结构的形成，通过调整在适当选择的胶体尺寸，有效重力（影响渗透深度）和刷覆盖密度的接枝基板上的胶体相互作用。
We investigate the interaction energy between two colloidal particles on or immersed in nonadsorbing polymer brushes grafted onto the substrate as a function of the separation of the particles by the use of a self-consistentfield theory calculation. Depending on the colloidal size and the penetration depth, we demonstrate the existence of a repulsive energy barrier of several k(B)T, which can be interpreted by separating the interaction energy into three parts: colloid-polymer interfacial energy, entropic contribution due to "depletion zone" overlap of colloidal particles, and entropic elastic energy of grafted chains by the compression of particles. The existence of a repulsive barrier which is of entirely entropic origin can lead to kinetic stabilization of the mixture rather than depletion flocculation or phase separation. Therefore, the present result may suggest an approach for controlling the self-assembling behavior of colloids for the formation of target structures, by tuning the colloidal interaction on the grafting substrate under appropriate selection of colloidal size, effective gravity (influencing the penetration depth), and brush coverage density.