Yuanrong Xin

A hierarchically porous cellulose monolith: A template-free fabricated, morphology-tunable, and easily functionalizable platform

Recently, monoliths with continuous porous structure have received much attention for high-performance separation/adsorption matrix in biomedical and environmental fields. This study proposes a novel route to prepare cellulose monoliths with hierarchically porous structure by selecting cellulose acetate (CA) as the starting material. Thermally induced phase separation of CA solution using a mixed solvent affords a CA monolith, which is converted into the cellulose monolith by alkaline hydrolysis. Scanning electron microscopy images of the CA and cellulose monoliths reveal a continuous macropore with rough surface, and nitrogen adsorption/desorption analysis indicates the formation of a mesoporous structure. The macroporous structure could be controlled by changing the fabrication parameters. A series of reactive groups are introduced by chemical modifications on the surface of the cellulose monolith. The facile and diverse modifiability combined with its hydrophilic property make the hierarchically porous cellulose monolith a potential platform for use in separation, purification and bio-related applications.

Synthesis of new bio-based polycarbonates derived from terpene

In this work, a bio-based polycarbonate has been synthesized successfully from terpene diphenol and diphenyl carbonate by melt polymerization without using any catalysts. The polymerization process involves no usage of toxic phosgene. The reaction parameters such as monomer feed ratio, polymerization temperature and time have been systematically examined. A little excess of diphenyl carbonate for terpene diphenol affords the highest molecular weight. The chemical structure of the product is identified by 1H NMR and FT-IR. The DSC analysis shows that the glass transition temperature of the present bio-based polycarbonate is much higher than that of a conventional bisphenol A-based polycarbonate due to the rigid molecular structure of terpene diphenol. In addition, a series of copolycarbonates with adjustable glass transition temperature are prepared from terpene diphenol and bisphenol A. The present polycarbonate and copolycarbonates with high thermal stability synthesized via an environmental benign process have large potential for bio-based engineering plastics in various industrial fields.

Facile fabrication of mesoporous poly(ethylene-co-vinyl alcohol)/chitosan blend monoliths.

Poly(ethylene-co-vinyl alcohol) (EVOH)/chitosan blend monoliths were fabricated by thermally-induced phase separation method. Chitosan was successfully incorporated into the polymeric monolith by selecting EVOH as the main component of the monolith. SEM images exhibit that the chitosan was located on the inner surface of the monolith. Fourier-transform infrared analysis and elemental analysis indicate the successful blend of EVOH and chitosan. BET results show that the blend monoliths had high specific surface area and uniform mesopore structure. Good adsorption ability toward various heavy metal ions was found in the blend monoliths due to the large chelation capacity of chitosan. The blend monoliths have potential application for waste water purification or bio-related applications.

Data in support of preparation and functionalization of a clickable polycarbonate monolith

This data article provides supplementary figures to the research article entitled, “Phase separation approach to a reactive polycarbonate monolith for “click” modifications” (Xin et al., Polymer, 2015, doi:10.1016/j.polymer.2015.04.008). Here, the nitrogen adsorption/desorption isotherms of the prepared porous polycarbonate monolith are shown to classify its inner structure and calculate the specific surface area. The monoliths were modified by using the thiol-ene click chemistry and the olefin metathesis, which was examined by contact angle measurements, FT-IR, solid state 13C NMR spectroscopy as well as thermogravimetric analysis.

An ideal enzyme immobilization carrier: a hierarchically porous cellulose monolith fabricated by phase separation method

Abstract Cellulose monolith with a hierarchically porous morphology was utilized as a novel solid support for enzyme immobilization. After a series of modifications, succinimidyl carbonate (SC)-activated cellulose monolith (SCCL monolith) was obtained and it was employed to immobilize a model enzyme (horseradish peroxidase, HRP) through covalent bonding. The HRP immobilization capacity on SCCL monolith was calculated as 21.0 mg/g. The thermal stability measurement illustrated that the immobilized HRP exhibited a largely improved thermal resistance compared to its free counterpart. The reusability of the immobilized HRP was investigated, and it could be reused at least 10 cycles without significant activity loss. Therefore, cellulose monolith is found to be an ideal solid support for enzyme immobilization.