Osmosis manipulable morphology and photonic property of microcapsules with colloidal nano-in-micro structure

Yuandu Hu; Chengnian Li; Jianying Wang; Xiaolu Jia; Jintao Zhu; Qin Wang; Hong Wang; Yajiang Yang

doi:10.1016/j.jcis.2020.04.062

Osmosis manipulable morphology and photonic property of microcapsules with colloidal nano-in-micro structure

J Colloid Interface Sci. 2020 Aug 15:574:337-346. doi: 10.1016/j.jcis.2020.04.062. Epub 2020 Apr 18.

Authors

Yuandu Hu¹, Chengnian Li¹, Jianying Wang¹, Xiaolu Jia¹, Jintao Zhu², Qin Wang¹, Hong Wang¹, Yajiang Yang³

Affiliations

¹ Hubei Key Lab of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
² Hubei Key Lab of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: jtzhu@hust.edu.cn.
³ Hubei Key Lab of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: yjyang@hust.edu.cn.

PMID: 32335483
DOI: 10.1016/j.jcis.2020.04.062

Abstract

Full visible spectrum photonic droplets and consequent microcapsules with nano-in-micro structure were prepared through microfluidic technique. Photo-curable resin and suspension of monodispersed soft nanogels were used as shell and core of the microcapsules, respectively. Upon UV irradiation, the droplets can be subsequently transformed into photonic microcapsules with an ultrathin polymeric shell. The shell thickness of the photonic microcapsules was found to be approximately 700 nm. Due to the ultrathin shell and soft core, the photonic microcapsules with nano-in-micro structure display dramatic changes both in shapes and photonic property under the impact of osmosis effect or temperature stimulus. Typically, the shell and core parts of nano-in-micro structure could respectively undergo a size expansion/even rupture and a size decrease/buckling under hypotonic and hypertonic condition. Correspondingly, the peak value of the reflection spectra of the microcapsules showed a redshift and blue shift, respectively. The mechanism to the structure and optical properties variation involves the osmotic pressure induced the volume-fraction change of the nanogel-based photonic dispersion and the shell buckling of the core/shell microcapsules.

Keywords: Microfluidic; Nano-in-micro structure; Osmotic pressure; Photonic microcapsules.