Suppression of cracking in drying colloidal suspensions with chain-like particles

Zhaoxia Niu; Yiping Zhao; Qiuting Zhang; Zhiyuan Zhao; Dengteng Ge; Jiajia Zhou; Ye Xu

doi:10.1063/5.0203112

Suppression of cracking in drying colloidal suspensions with chain-like particles

J Chem Phys. 2024 Apr 28;160(16):164901. doi: 10.1063/5.0203112.

Authors

Zhaoxia Niu¹, Yiping Zhao², Qiuting Zhang¹, Zhiyuan Zhao³, Dengteng Ge², Jiajia Zhou^{4

5}, Ye Xu¹

Affiliations

¹ School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China.
² Institute for Engineering and Technology, Xinxing Cathay International Group, Shanghai 201403, China.
³ Wenzhou Institute, University of Chinese Academy of Science, Wenzhou, Zhejiang 325000, China.
⁴ South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
⁵ Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, China.

PMID: 38656445
DOI: 10.1063/5.0203112

Abstract

The prevention of drying-induced cracking is crucial in maintaining the mechanical integrity and functionality of colloidal deposits and coatings. Despite exploring various approaches, controlling drying-induced cracking remains a subject of great scientific interest and practical importance. By introducing chain-like particles composed of the same material and with comparable size into commonly used colloidal suspensions of spherical silica nanoparticles, we can significantly reduce the cracks formed in dried particle deposits and achieve a fivefold increase in the critical cracking thickness of colloidal silica coatings. The mechanism underlying the crack suppression is attributed to the increased porosity and pore sizes in dried particle deposits containing chain-like particle, which essentially leads to reduction in internal stresses developed during the drying process. Meanwhile, the nanoindentation measurements reveal that colloidal deposits with chain-like particles exhibit a smaller reduction in hardness compared to those reported using other cracking suppression approaches. This work demonstrates a promising technique for preparing colloidal coatings with enhanced crack resistance while maintaining desirable mechanical properties.