Environmental Science-Nano
·
2021
·Vol. 8
·期 3
·698-710
·
IF 8.131
Kejian Li,Xiaozhong Fang,Tao Wang,Kedong Gong,Muhammad Ali Tahir,Wei Wang,Jin Han,Hanyun Cheng,Guanjun Xu,Liwu Zhang
Water-soluble low-molecular-weight dicarboxylic acids (DCAs) and corresponding salts are ubiquitous in the atmosphere. They could efficiently form chelates with iron in atmospheric particles, which could be photoexcited to generate a series of strong oxidants, and have profound impacts on atmospheric chemistry. However, the influences of iron–DCAs complexes on the heterogeneous uptake of atmospheric trace gases are unclear. In this study, the effects of dominant dicarboxylic acid salts (including oxalate, malonate, and succinate) on the heterogeneous SO2 conversion with hematite nanoparticles were systematically investigated using film flow reaction and in situ DRIFTs experiments. It was found that a trace amount of DCA salts could significantly accelerate sulfate formation under solar light illumination. Additionally, similar results were also observed on the Arizona test dust, a proxy of authentic mineral dusts. Moreover, the iron solubility was increased owing to the effects of oxalate complexation, especially under light irradiation. Furthermore, the reaction mechanisms for the enhanced SO2 uptake and iron dissolution in the presence of DCA salts were proposed, and atmospheric environmental implications were discussed.
研究领域:
环境科学
·
大气化学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2025
·
IF 4.3
Chenru Tian,Ganggang Zhang,Jun Liu,Liqun Zhang
The conventional curing methods pose a significant environmental threat due to the use of toxic vulcanizing agents, the release of irritating volatile organic compounds, and the difficulties in recycling end-of-life rubber products. This work demonstrates a catalyst-free, facile, and eco-friendly crosslinking strategy based on the reaction between epoxy-functionalized ethylene-propylene-diene monomer (EEPDM) and dicarboxylic acids. The EEPDM was synthesized via a reusable reaction-controlled phase-transfer catalyst. Then, EEPDM could be effectively crosslinked by dicarboxylic acids without additional additives. The increased acidity of dicarboxylic acids could be conducive to improving the crosslinking rate. Moreover, the curing mechanism and the nature of the crosslinks were investigated, which is crucial for the recyclability of rubbers. The dicarboxylic acid-cured EEPDM exhibited undesirable side reactions, the extent of which showed a positive correlation with the acidity of carboxylic groups. This phenomenon could be primarily attributed to acid-catalyzed self-polymerization via epoxide ring-opening mechanisms, which would be detrimental to the reprocessability. Due to the formation of thermally stable ether linkages, the crosslinked EEPDM exhibited enhanced thermal-oxidative aging behavior. Hence, we envision that this catalyst-free, high-efficiency crosslinking strategy may offer a promising bridge between sustainable modification and high-performance for epoxy-functionalized rubbers, holding potential application in eco-friendly, low-odor automotive sealing strips.
研究领域:
高分子科学
·
材料工程
·
绿色化学
·
橡胶技术
·
化学合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Meiming He,Wanfen Pu,Zhiwu He,Lijun Zheng,Xuerui Yang,Wei Qian
The low permeability and strong heterogeneity of low-permeability reservoirs result in low recovery rates from water flooding, making it challenging for conventional methods to effectively extract crude oil. Nano-SiO 2 , with its advantages of small particle size, low cost, and ease of modification, has garnered significant attention in the field of enhanced oil recovery. This study systematically investigates the emulsification performance, interfacial tension, and interfacial viscoelasticity of nano- SiO 2 modified with fatty acids, fatty amines, and aromatic carboxylic acids through multiscale experimental methods, revealing the structure-property relationships between the modifier’s molecular structure and the resulting interfacial performance. The experimental results demonstrate that the modified nano-SiO 2 significantly enhances emulsion stability and interfacial activity. Notably, the benzoic acid-modified nano-SiO 2 exhibits the best performance, achieving an internal phase inversion point (IPIP) of 85 %, reducing interfacial tension to 5.61 mN/m, and yielding a comprehensive modulus of 25.26 mN/m. The carbon chain length, functional group type, and number of aromatic rings significantly influence emulsification performance and interfacial tension. Composite modification with benzoic acid and dodecanoic acid (4:1) further optimizes emulsion stability. This study provides a theoretical foundation and technical support for developing efficient and stable nano-emulsifiers, offering new strategies for enhancing oil recovery in low-permeability reservoirs.
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2025
·
IF 7.3
Mengtong Wang,Ying Miao,Rikun Liu,Liang Shen,Yingying Du,Changqing Fu
The use of bisphenol A (BPA) in traditional waterborne epoxy coating formulations is harmful to human health, and the low toughness of the cured film severely limits its application in many areas. Most BPA alternatives enhance the toughness of the epoxy cured film but compromise the coating's properties to varying degrees. Therefore, developing a BPA alternative that toughens epoxy resins without sacrificing modulus and mechanical strength remains a significant challenge. In this study, we synthesized dicarboxylic acid compound (PNP) with a structure similar to BPA, using phthalic anhydride and neopentyl glycol. This compound serves as a substitute for BPA. We systematically explored the influence of different PNP contents on the performance of waterborne epoxy resins and coatings. The results showed that PNP is more conducive to preparing waterborne epoxy resins with smaller particle sizes and stable heat storage. Compared with BPA-modified epoxy resin, PNP significantly increases the elongation at break and tensile strength of the cured film. Moreover, different PNP contents can significantly improve the coating's impact resistance, pull-off adhesion, water resistance, salt spray resistance, and acid resistance without affecting other mechanical properties and alkali resistance. This study provides a new perspective for preparing environmentally friendly, high-performance, tough, and stable waterborne epoxy coatings.
研究领域:
材料科学
·
高分子化学
·
涂层技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）