A new article out of a collaboration between Dr. Ning Yan and Dr. Jing Chen’s labs has been published in Science of The Total Environment written by Jialong Wu, Xiaozhen Ma, Pitchaimari Gnanasekar, Fan Wang, Jin Zhu, Ning Yan and Jing Chen.

You can find the article here.

Abstract

Superhydrophobic polyurethane foam is one of the most promising materials for oil-water separation. However, there are only limited studies prepared matrix superhydrophobic foams as adsorbents. In this paper, SiO₂ modified by 1H, 1H, 2H, 2H-perfluorododecyl trichlorosilane (F-SiO₂) was added into the lignin-based foam matrix by a one-step foaming technique. The average diameter of F-SiO₂ was about 480 nm with an water contact angle (WCA) of 160.3°. The lignin-based polyurethane foam with F-SiO₂ had a superhydrophobic water contact angle of 151.3°. There is no obvious change in contact angle after 100 cycles of compression or after cutting and abrasion. Scanning electron microscopy (SEM) analysis showed that F-SiO₂ was distributed both on the surface and inside of the foam. The efficiency for oil-water separation reached 99 %. Under the light intensity of 1 kW/m², the surface temperature of the lignin-based foam rose to 77.6 °C. In addition, the foam exhibited self-cleaning properties and degraded within 2 h in an alcoholic alkali solution. Thus, in this study, we developed a novel matrix superhydrophobic lignin-based polyurethane foam with an excellent promise to be used as oil water separation adsorbents in industrial wastewater treatment and oil spill clean-up processes.

A new article out of Ning Yan’s lab has been published in Carbohydrate Polymers written by Mohammad H Mahaninia and Ning Yan.

Click here to obtain an e-print of the full article for free until January 5th 2023.

Abstract

This study reports a first example of chitosan-based dynamic covalent framework materials successfully prepared through one-pot/ultrasonic-assisted amidation reaction via either citric acid (CA) or trimesic acid (TMA) as the linker unit under moderate conditions. Chitosan-based framework materials with residual carboxylic acid functional groups were obtained by tripodal cross-linking reactions without the need of any catalyst. The obtained materials were capable of bond exchange via neighboring group participation (NGP) effect within their dynamic covalent networks. It was demonstrated that the chitosan-based framework materials could undergo a dynamic transamidation reaction to exhibit self-healing characteristics. The structural properties of the synthesized dynamic covalent framework materials were controlled by the type and composition of the tripodal cross-linkers. This study showcased a novel approach to synthesize biodegradable, self-healing, pH-responsive, and selective mixed-dye adsorbent materials using chitosan as the building block.