title: Cavitation in drying droplets of soft matter solutions.
abstract: When a droplet of a soft matter solution is dried, cavities are often formed in the droplet, giving a hollow sphere in the end. A theoretical model is given for this phenomenon. It is shown that the formation of a gel-like layer (skin layer), which has a finite shear modulus, is essential for the phenomenon to take place. The condition for cavity formation (how it depends on the shear modulus and thickness of the skin layer), and the variation of the droplet volume and cavity volume after the cavity formation are examined.
authors.affiliation: State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China and Kavli Institute for Theoretical Physics China, Beijing 100190, China and Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, China.
authors.forename: Fanlong
authors.initials: F
authors.lastname: Meng
authors.affiliation: Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, China.
authors.forename: Masao
authors.initials: M
authors.lastname: Doi
authors.affiliation: State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China and Kavli Institute for Theoretical Physics China, Beijing 100190, China and Center for Advanced Study, Tsinghua University, Beijing 100084, China.
authors.forename: Zhongcan
authors.initials: Z
authors.lastname: Ouyang