The freeze-drying technique is an attractive method because it is an environmental friendly and cost-effective shaping process for preparing advanced materials with interconnecting pore channels or pore gradients in bodies. Freeze-drying technology is a kind of methods to build porous structural material efficiently and controllably. In recent years many new polymer-based materials prepared by freeze-drying have exhibited broad applications as functional materials. This article reviews the progress of advanced polymer materials prepared by freeze-drying, and summerizes the applications in the field of materials engineering, environment, biomedicine and other prospects. The research prospects and directions of this rapidly developing field are also briefly addressed.

Contents
1 Introduction
2 The fabrication of polymer-based materials by direct freeze-drying
2.1 Solution freeze-drying
2.2 Emulsion freeze-drying
3 The fabrication of polymer-based materials by indirect freeze-drying
4 Applications of polymer-based materials prepared by freeze-drying
4.1 The application in tissue engineering and medicine
4.2 The application in the fields of adsorption and separation
4.3 The application in conduct electricity and gas detection
5 Conclusion