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Updated: Jan 7, 2026

Generation of Size-controlled Poly ethylene Glycol Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices
Published on: July 3, 2018
Amorphous Deposit Formed by Evaporation of Poly(Ethylene Glycol) Aqueous Droplet
Shengpei Shao1, Qingyou Liang2, Jiajia Zhou3
1School of Marine Science and Engineering, South China University of Technology, Guangzhou, China.
Abstract:
Crystallization of poly(ethylene glycol) (PEG) greatly debase the quality of printing and coating during drying, where it is used as a dispersant. In this work, we have investigated the drying process of aqueous droplet of poly(ethylene glycol) (PEG) as a function of molecular weight (Mw). It shows that PEG would crystallize on a hydrophilic surface but form an amorphous deposit on a hydrophobic surface at a humidity (RH) of 40% when Mw ≤5000 g/mol. However, PEG would crystallize regardless of the surface and RH when Mw is above 10 000 and 20 000 g/mol. By regulating PEG concentration, molecular weight, and RH, the droplet can be dried into an amorphous deposit for over 24 h. Raman spectroscopy and low-field nuclear magnetic resonance (LF-NMR) indicate that the water molecules bound to PEG chains (Mw ≤5000 g/mol) under slow drying inhibit their crystallization.
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