POLYMER ENGINEERING AND SCIENCE
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2025
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IF 3.2
Qingjie Ma,Jun Li,Rui Liu,Yajun Wu,Zuguo Yang,Beibei Wu,Yuxuan Yang,Wanfen Pu
Polymeric hydrogels, known as blocking gel or disproportionate-permeability-reducer, have been highly successful in improving sweep efficiency and reducing excessive water cut by adjusting reservoir heterogeneity (Al-Muntasheri and Zitha. Gel under dynamic stress in porous media: new insights using computed tomography. SPE Saudi Arabia Section Technical Symposium; 2009. Al-Sharji, Grattoni, Dawe, et al. Pore-scale study of the flow of oil and water through polymer gels. SPE Annual Technical Conference and Exhibition; 1999. Bai. Preformed particle gel for conformance control: factors affecting its properties and applications. SPE Reservoir Eval Eng. 2007;10:415–422). However, it remains an extremely challenging task to develop polymeric weak gel for in-depth conformance control, simply because most in situ synthetic weak hydrogels suffer from loosely structured network and lack of efficient energy dissipation mechanism in harsh temperature environment (Bai, Leng, and Wei. A comprehensive review of in-situ polymer gel simulation for conformance control. Pet Sci. 2022;19(1):189–202. Bhattacharya and Samanta. Soft-nanocomposites of nanoparticles and nanocarbons with supramolecular and polymer gels and their applications. ACS Appl Mater Interfaces. 2016;8(19):21512. Bai, Zhou, and Yin. Comprehensive review of polyacrylamide polymer gels for conformance control. Pet Explor Dev . 2015;42(4):525–532). This paper introduces a low-cost, high-temperature resistant, polymer covalent weak gel system. Polyethylenimine (PEI) and polyethylenimine-modified nano-SiO 2 nano-crosslinker were used as crosslinkers, and the performance of the gel system under high temperatures was systematically evaluated. The studied gel properties include gel formation time, gel strength, thermal stability, infrared spectroscopy, rheological properties, long-term stability, and microstructure. Acrylamide/2-acrylamido-2-methyl propane sulfonate (named QC-9 in this paper) is used in the gel system at concentrations as low as 2250 mg/L, and the gel time can be controlled within 3–12 h by adjusting the ratio of the polymers and crosslinkers. The gel exhibits a viscosity of 100–200 mPa·s, withstands temperatures up to 130°C, and has a salt tolerance of 214818.52 mg/L, with a viscosity retention rate of ≥80% after 70 days. At a shear rate of 1 Hz, the elastic modulus ( G ′) after aging for 70 days is 1.07 Pa, and the viscous modulus ( G ″) is 0.25 Pa. The test results indicate that the gel system remains in the high-viscosity range. Thermogravimetric Analysis tests indicate that the structural destruction temperature of the composite gel is 140°C, the activation energy of the nanocomposite crosslinking polymer weak gel is 5.2 and 16.5 kJ/mol higher for the evaporation of free water and the escape of bound water, respectively, compared to that of the PEI-crosslinking microgel. Finally, scanning electron microscopy and atomic force microscopy were used to observe the gel's microstructure. Compared to traditional PEI crosslinked gel systems, the organic/inorganic nanocomposite crosslinked gel system has a dense, thickened network structure. Highlights Low-cost, high-temperature polymer gel with PEI-modified nano-SiO 2 . Adjustable gel formation and viscosity. High salt tolerance and long-term viscosity retention. Stable up to 140°C with higher activation energy than PEI-crosslinked microgel. Dense network structure with superior thermal stability.
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DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
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2025
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IF 3.2
Qing Xu,Xinxin Wang,Chao Dong,Yuhan Wei,Zhibo Li
A blend of poly(lactic acid) (PLLA) and poly(4-hydroxybutyrate)-based polyurethane prepolymer (P4HBU) was prepared through reactive blending in this study. Thermal properties, mechanical properties, rheological properties, and the degradation behavior of the PLLA/P4HBU blends were investigated as varying the P4HBU content. Dynamic mechanical analysis indicated that the glass transition temperatures of PLLA and P4HBU got closer to each other after melt blending, implying that the compatibility between them was improved. With the increase of P4HBU content increased, the elongation of the PLLA/P4HBU composite enhanced obviously, as well as the notched impact strength. When the P4HBU content reached 20 wt%, the elongation increased to 196.2% and the notched impact strength increased to 8.4 kJ/m 2 , respectively, about 26.2 and 2.4 times those of PLLA homopolymer. Meanwhile, the tensile strength decreased to 30.5 MPa. Scanning electron microscopy results proved that the shear yielding of the PLLA matrix and cavitation were the primary toughening mechanisms, resulting in an enhanced ductility of the PLLA/P4HBU blends. The degradation rate of the PLLA/P4HBU blends was improved for the incorporation of the P4HBU. Highlights P4HBU improved PLLA elongation (196.2%) and impact strength (8.4 kJ/m 2 ). Tensile strength of PLLA/P4HBU was reduced to 30.5 MPa. The compatibility between PLLA and P4HBU was enhanced. Shear yielding and cavitation were the primary toughening mechanisms. The degradation rate of the PLLA/P4HBU blends was improved.
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DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
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2025
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IF 3.2
Sevilay Dural,Sebnem Camadanlı,Nilhan Kayaman Apohan
Poly(aspartic ester polyurea) (PAEU) coating systems, which feature an uncatalyzed and solventless reaction, have attracted attention as a more environmentally friendly, nonreactive coating alternative in both academia and industry. In these coatings, achieving optimal performance requires an impeccable combination of aliphatic polyisocyanates and polyaspartic esters used as cross-linking agents. In previous applications, petroleum-based polyisocyanates were used as the second component. In this study, a biobased prepolymer was synthesized as the second component, thus creating a sustainable PAEU coating class without compromising traditional properties. It is known that traditional coatings can become damaged or cracked when exposed to external forces during processing or use. The coatings achieved the self-healing feature by using varying amounts of disulfide to improve this situation. The samples were deliberately damaged and then allowed to heal for 1 h at room temperature, 40°C, and 80°C. The results demonstrated improved mechanical properties in all samples. Tensile strength increased by 79%–95%, and elongation recovery rates ranged from 73% to 97% after 1 h of room-temperature repair. These mechanical test results were consistent with the SEM images for all samples.
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DOI
高影响因子
ACS Nano
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2025
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IF 16
Jingyuan Wang,Xiaoyan Li,Panpan Chen,Rong Li,Jingwei Hu,Xiangwei Wu,Yi Wang,Hui Li
Nanopesticides (NPs) provide a sustainable approach to reducing the use of chemical pesticides and mitigating their environmental risks in agriculture. In the present study, a pH and cellulase dual-stimulating system with the loaded pesticide penthiopyrad (PEN) was developed by incorporating hydroxypropyl cellulose (HPC) on the surfaces of mesoporous nanoselenium (MSe). In the measurement of antifungal efficacy of PEN against Colletorichum orbiculare Arx, compared to the neutral environment, i.e., pH = 7 without cellulase, the cumulative release of PEN from HPC@PEN@MSe NPs increased 5.7 and 4.8 times of the amount released at pH 3 and 5, respectively; at pH 7, the presence of cellulase solution substantially enhanced PEN release by 6.1 times more than that without cellulase. The HPC@PEN@MSe NPs demonstrated 3.2-fold of antifungal efficacy greater than the commercial 20% PEN suspension concentrate (20% PEN SC). This dual-stimulating NPs can induce oxidative stress responses and cell structural damage in pathogens, demonstrating a broad spectrum of antifungal activity. Mechanistic investigations illustrated that HPC@PEN@MSe NPs specifically promote the accumulation of reactive oxygen species, including hydroxyl radicals (•OH), superoxide radicals (•O2–), and singlet oxygen (1O2) in pathogenic cells by regulating gene expressions relevant to oxidative phosphorylation and lipid metabolism pathways, ultimately leading to eradication of pathogens. In vivo, HPC@PEN@MSe NPs sprayed could be transported in plants and specifically activated at the infected leafy, stem, and root tissues of cucumber plants, with the maximum PEN concentration at 0.93 mg/kg detected in the infected leaves at 12 h. The PEN residual concentration still had 0.09 mg/kg after 14 days, which suggests long-lasting activity. Moreover, the results of detached cucumber leaves and pot experiments indicated that HPC@PEN@MSe NPs significantly increased antioxidant enzyme levels, enhanced resistance to anthracnose, and manifested no apparent effects on plant growth. This eco-friendly plant protection strategy developed in this study exhibits apparent potential in practical applications while maintaining ecological sustainability and providing a potential path to address plant health management in modern agriculture.
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PubMed
高影响因子
危险品化学品经营许可证（带存储）