Qianqian Wang,Pengwu Xu,Weijun Yang,Tianxi Liu,Martin Hoch,Piming Ma
The current cross-link method in rubber industry is suffering from the utilization of toxic curing packages and the release of volatile organic compounds (VOCs). In this work, we propose a green cross-link route to make robust rubber materials. To prove this concept, ethylene-vinyl acetate-glycidyl methacrylate copolymer (EVM-GMA) functionalized with silane groups, i.e., EVM-Si(OC 2 H 5 ) 3 as a model rubber was firstly designed by solvent-free compounding. Then, the silane groups of EVM-Si(OC 2 H 5 ) 3 rubber are hydrolyzed and cross-linked with water molecules. The cross-link density, tensile strength and hardness of the EVM-Si(OC 2 H 5 ) 3 rubber increased gradually with temperature up to 200 °C. Subsequently, the water cross-linked EVM-Si(OC 2 H 5 ) 3 rubber was reinforced with silica (SiO 2 ) that created a secondary network via an in situ interfacial reaction between the –OH groups of SiO 2 and the silane groups of EVM-Si(OC 2 H 5 ) 3 . As a consequence, the SiO 2 nanoparticles could be evenly dispersed in the rubber matrix with strong interfacial bonding . The tensile strength and elongation at break of the EVM-Si(OC 2 H 5 ) 3 /SiO 2 nanocomposites reached to 10.0 MPa and 800%, respectively at a SiO 2 loading of 30 phr. Thus, the new cross-link strategy addressed here may promote the development and application of rubber industry in some environmental-friendly domains.
Cyclodextrin-based metal-organic framework (CD-MOF) has been widely used in various delivery systems due to its excellent edibility and high drug loading capacity. However, its typically bulky size and high brittleness in aqueous solutions pose significant challenges for practical applications. Here, we proposed an ultrasonic-assisted method for rapid synthesis of uniformly-sized nanoscale CD-MOF, followed by its hydrophobic modification through ester bond cross-linking (Nano-CMOF). Proper ultrasound treatment effectively reduced particle size to nanoscale (393.14 nm). Notably, carbonate ester cross-linking method significantly improved water stability without altering its cubic shape and high porosity (1.3 cm 3 /g), resulting in a retention rate exceeding 90% in various media. Furthermore, the loading of quercetin did not disrupt cubic structure and showcased remarkable storage stability. Nano-CMOF achieved controlled release of quercetin in both aqueous environments and digestion. Additionally, Nano-CMOF demonstrated exceptional antioxidant (free radical scavenging 82.27%) and biocompatibility, indicating its significant potential as novel nutritional delivery systems in food and biomedical fields.
Ruixian Zhang,Yuanbin Mo,Yanfei Gao,Zeguang Zhou,Xueyi Hou,Xiuxiu Ren,Junzhong Wang,Xiaokun Chu,Yanyue Lu
Oil/water mixtures from industrial and domestic wastewater adversely affect the environment and human beings. In this context, the development of a facile and improved separation method is crucial. Herein, dopamine was used as a bioadhesive to bind tea polyphenol (TP) onto the surface of a polyvinylidene fluoride (PVDF) membrane to form the first hydrophilic polymer network. Sodium periodate (NaIO4) is considered an oxidising agent for triggering self-polymerisation and can be used to introduce hydrophilic groups via surface manipulation to form the second hydrophilic network. In contrast to the individual polydopamine (PDA) and TP/NaIO4composite coatings for a hydrophobic PVDF microfiltration membrane, a combination of PDA, TP, and NaIO4has achieved the most facile treatment process for transforming the hydrophobic membrane into the hydrophilic state. The hierarchical superhydrophilic network structure with a simultaneous underwater superoleophobic membrane exhibited excellent performance in separating various oil-in-water emulsions, with a high water flux (1530 L.m−2h−1.bar) and improved rejection (98%). The water contact angle of the modified membrane was 0° in 1 s. Moreover, the steady polyphenol coating was applied onto the surface, which endowed the membrane with an adequate antifouling and recovery capability and a robust durability against immersion in an acid, alkali, or salt solution. This facile scale-up method depends on in situ plant-inspired chemistry and has remarkable potential for practical applications.Keywords:superior separation method;hierarchical superhydrophilic network;steady polyphenol coating;oil-in-water emulsion
危险品化学品经营许可证（带存储）