Kinetics of Supercritical Drying of Gels

Gels

Can Erkey¹  İbrahim Şahin¹  Yaprak Özbakır¹  Zeynep İnönü¹  Zeynep Ulker² 

[1] Department of Chemical and Biological Engineering, Koç University, Rumelifeneri Yolu, Sarıyer, Istanbul 34450, Turkey;Department of Pharmacy, Altınbaş University, Mahmutbey Dilmenler Caddesi, No: 26, Bağcılar, Istanbul 34217, Turkey;

关键词: aerogel;    supercritical drying;    kinetics;    mass transfer;    diffusion;    spillover;    expanded solvents;    modeling;   

DOI  :  10.3390/gels4010003

来源: DOAJ

【 摘 要 】

Supercritical drying of gels is considered as the most important step of aerogel production since it enables preservation of the three-dimensional pore structure which lead to unique material properties such as high porosity, low density, and large surface area. An understanding of the kinetics of supercritical drying is necessary to provide insight into material development, scale-up, and optimization of the aerogel manufacturing process. Thus, investigation of supercritical drying is gaining increased attention in recent years. This review paper covers the experimental considerations and techniques to study the kinetics of supercritical drying, fundamental mass transfer mechanisms during the drying process and modeling efforts to predict the drying kinetics for varying operating conditions and gel properties. Transport phenomena involving diffusion, convection, spillage by volume expansion, and axial dispersion are discussed by providing the fundamental equations and empirical correlations to predict transfer coefficients. A detailed review of literature covering experimental and theoretical studies on kinetics of supercritical drying is presented.

【 授权许可】

Unknown