New Class of Model Porous Materials Prepared by Colloidal Self-assembly Methods

Understanding the properties of complex fluids (both liquid and gas) in porous media is crucial for both fundamental science and application, especially for many industrial problems, such as water filtration, protein chromatography, reservoir capacity estimation and productivity of shale gas. Confinement, at the scale observed in many porous media, can lead to dramatic shifts in physical properties such as gas density, phase transitions, and diffusivity. With the development of many nanoscale processing techniques it has become increasingly urgent that detailed structural and phase behavior of materials be probed with the confinement length scales from 1 nm- 10 µm. For this purpose, a model porous material with well controlled pore properties (size, shape and surface chemistry) need be developed. We herein introduce a new class of model porous materials prepared by self-assembly of colloidal particles.
The essential of NPs assembly is the controlling of interactions. We have used silica NPs as building blocks suspended in a lutidine/water mixture. This method can be scaled up to synthesize monolithic solid porous materials with almost any designed shape on the scale of a few millimeters to centimeters. They are glass-like solids and have enough mechanical strength.