Scalable and rapid preparation of Janus fabric by trans-printing method for efficient oil/water emulsion separation

Abstract

The old-fashioned yet effective trans-printing method was adopted to prepare Janus fabric in the study. Nonwoven cotton fabric was firstly immersed in tetrahydrofuran solution containing P(DMAEMA-co-TMSPMA), a polymer synthesized by copolymerization between N, N-dimethylaminoethyl methacrylate (DMAEMA) and 3-(trimethoxysilyl)propylmethacrylate (TMSPMA), followed by thermal treatment, thus endowing the fabric with the demulsification property. Next, one side of the above prepared fabric was overlapped and rolled with donor fabric containing PDMS-g-TMOS, a polymer synthesized by thiol/ene click reaction between multi-vinyl poly(dimethylsiloxane) (vinyl-PDMS) and 3-mercaptopropyltrimethoxysilane (MPTMOS). The PDMS-g-TMOS polymer infiltrated into the fabric cured with P(DMAEMA-co-TMSPMA) to a certain depth, followed by thermal treatment. Thus, the resultant fabric had both the superhyrophilic side for oil coalescence and the superhyrophobic side for oil permeation. The Janus fabric structure was confirmed by metalloscope, unidirectional water transport property (UDWT), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). When the prepared fabric was used to separate model oil hexadecane (HD) from oil-in-water emulsion, the maximum separation speed was 134.5 kg h⁻¹ m⁻². The recovery rate of HD respectively reached 96.0% after 60 min and 99.9% after 150 min. The Janus fabric prepared by the trans-printing method is particularly suitable for industrial production and of great industrial value.

Graphical Abstract

Keywords:

• Janus fabric
• oil/water separation
• demulsification
• trans-printing

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was supported by the GDAS’ Project of Science and Technology Development (numbers 2019GDASYL-0103026 and 2018GDASCX-0104); the CAS “Light of West China” Program under Grant (number XAB2017AW04); and the General Project of Guangzhou Scientific Research under Grant (number 201804010139).