Cellulose acetate (CA) aerogels suffer from poor water stability and limited active sites, hindering their practical use in dye wastewater treatment. To overcome this, we developed a robust CA aerogel using a novel synergistic strategy of covalent crosslinking with polyisocyanate (PHDI) followed by in situ precipitation of calcium carbonate (CaCO3). The resulting CaCO3/CA-PHDI composite aerogel exhibits exceptional adsorption performance for Congo red, achieving a high removal efficiency of 97.8%, a maximum capacity of 191.6 mg g−1, and stable operation across a wide pH (3–11) and temperature (25–65 °C) range. The adsorption follows pseudo-second-order kinetics and the Langmuir isotherm, indicative of monolayer chemisorption. The primary mechanism is identified as coordination between Ca2+ and sulfonate groups, synergized by hydrogen bonding and electrostatic interactions. Furthermore, the aerogel maintains over 73% removal after five regeneration cycles. This work provides a high-performance adsorbent and elucidates the organic–inorganic synergistic enhancement mechanism, offering a new design strategy for functional biomass materials in practical wastewater remediation.
The adipic acid glycidyl methacrylate (AA-GMA) containing double bond of carbon and hydroxyl as an ultraviolet-polyurethane dual-curing oligomer was prepared as a precursor to resin for three-dimensional (3D) printing. A dual-curing resin for 3D printing was formulated from the AA-GMA, PHDI (hexamethylene diisocyanate-based polyisocyanates, mainly trimer) and other reagents. The dual-curing oligomer AA-GMA was synthesized by the epoxide ring-opening reaction with dicarboxylic acid and the molecular structure of which was characterized by FTIR and 1 H NMR analyses. AA-GMA has the double bond which could be cured via ultraviolet irradiation in the 3D printing process, and the hydroxyl could be cured by PU curing agent PHDI at the thermal post-curing process. The PHDI was not only employed as a diluent in the 3D printing process, but also acted as a reactant for post-curing. Compared to the traditional single-curing resin, this dual-curing resin could provide products with increased crosslinking density, flexibility and reduced volumetric shrinkage rate. The tensile strength of dual-curing sample was improved to 64 MPa after adding 20 wt% PHDI, which showed 18% boost compared to the sample without the PHDI. For the sample with a content of 30 wt% PHDI, the glass transition temperature ( T g ) was about 121 °C, presenting 35 °C higher than that of the blank sample.
Liangdong Liu,Jingjing Wei,Kin Man Ho,Kwan Yeung Chiu,To Ngai
Hypothesis : Encapsulation of sensitive water-soluble bioactive materials such as fragrances , polyphenols and enzymes poses an immense challenge with capsules templated from water-in-oil (w/o) emulsions. Generation of radicals, heating, and extreme pH that are necessary for shell formation through interfacial reactions may have undesired influences on the active ingredients and thus lower their activity. Experiments To overcome these limitations, we present a method to encapsulate sensitive ingredients, whereby capsules are templated from a w/o Pickering emulsion stabilized by binary particles of different hydrophilicity levels; the particles assembled at the water/oil interface are then crosslinked by polydiisocyanate (PHDI) at room temperature and neutral pH. Zein and casein nanoparticles were used as hydrophilic stabilizers and lipase was chosen as a model sensitive biomolecule that was encapsulated in the water core. Findings Our results indicated that the enzymes encapsulated in colloid capsules had higher activity than those encapsulated in traditional w/o Pickering emulsion without shell crosslinking. The capsule structure effectively protected enzymes from the outer environment. This method is well suited for the encapsulation and protection of sensitive ingredients and shows great application in food, drug, and cosmetic industries.
危险品化学品经营许可证（带存储）