CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2020
·
IF 3.35
Shaojian Hu,Jianhua Zhu,Bencheng Wu,Rui Ma,Xiaohui Li
As an eco-friendly lubricant base oil, ester base oil is receiving increasing attention. However, studies on synthetic reaction kinetics of high viscosity complex ester have been rarely reported. In this work, based on the principle of equal reactivity of all functional groups and simplified kinetics models, synthetic reaction kinetics for high viscosity complex ester was investigated in two steps. As for the esterification of trimethylolpropane with glutaric acid, the activation energies of the first and second stage were 55.3 and 73.5 kJ/mol, respectively. As for the esterification of the first step products with 2-ethylhexanoic acid, the activation energies of the first and second stage were 60.6 and 98.2 kJ/mol, respectively. As for the esterification of the first step products with n -heptanoic acid, its activation energy was 68.9 kJ/mol. A mutation phenomenon on reaction order from zero to second order was discovered, which could be explained by the strong adsorption of organic acid on catalyst surface. The conversion rate of carboxyl of synthetic reaction for mixed acid ester was estimated by simulation, and average relative error was less than 3.0%. The synthetic process of high viscosity complex ester was considered to consist of a series of parallel–consecutive reactions with addition–elimination mechanism.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2015
·
IF 2.252
Yin Yu,Bo Jin,Rufang Peng,Lisheng Fan,Longhua Cai,Bin Fan,Shijin Chu
A series of [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) analogs with different ester structures, such as isopropyl ester (F 1 ), sec-butyl ester (F 2 ), ethyl ester (F 3 ), 2-thiopheneethyl ester (F 4 ), phenethyl ester (F 5 ), and 4-methoxyphenethyl ester (F 6 ), were designed, synthesized, and evaluated for their photovoltaic performance. The optical, electrochemical, morphological, and photovoltaic properties of the molecules were characterized through UV–vis spectroscopy, cyclic voltammetry, and atomic force microscopy; then, the effects of different ester structures on these properties were investigated. Results showed that polymer solar cells (PSCs) with P3HT as a donor and F 1 –F 6 as acceptors displayed different photovoltaic properties. The PSCs with F 1 , F 2 , and F 3 as acceptors showed higher photovoltaic performance than those with F 4 , F 5 and F 6 as acceptors. Moreover, the power conversion efficiency of the former three PSCs exceeded or approached 3.0%, whereas that of the latter three PSCs was below 2.0%. Compared with PCBM, F 2 and F 3 with an aliphatic ester exhibited a slightly better photovoltaic performance, F 1 with isopropyl ester displayed similar photovoltaic properties, and other aromatic ring ester PCBM-like derivatives showed poorer photovoltaic performance.
研究领域:
材料科学
·
光电化学
✓ 已验证
DOI
高影响因子
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Yi Zhang,Cheng Peng,Gang Wang,Xinrong Huang,Yingfeng Yu
Fabricating epoxy resins low in both dielectric properties and moisture absorption is of emerging need but challenging, especially in the application of microelectronic packaging materials that are intensively exposed to harsh environments. In this work, a series of diphenols of different substituent positions and groups blocked with ester groups were copolymerized with diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin to synthesize high-molecular-weight hydroxyl-free epoxy thermoplastics (phenoxy resins). Remarkably low dielectric constants down to 2.26 at 1 MHz and low dielectric losses were found in these hydroxyl-free epoxy thermoplastics, which also showed excellent hydrophobicity compared with those of epoxy thermosets and commercialized epoxy thermoplastic. The migration of ester groups in the polymerization process was studied by a series of model reactions, indicating that the reaction mainly undergoes an associative mechanism under catalysis of the imidazole derivative. In addition, the polymers demonstrated good thermal stability, while thermal properties can be easily modulated by changing the substituent group of phenolic ester monomers. In short, these hydroxyl-free epoxy thermoplastics could be a promising candidate for antimoisture microelectronic packing materials and have versatile applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2014
·Vol. 14
·期 7
·4837-4842
·
IF 1.339
Liu Hanxia,Song Zhijian,Chen Xuemei
A photocleavable nitrobenzyl ester group was introduced in the backbone of self-assembling peptides using standard Fmoc-peptide systhesis. The nitrobenzyl ester group could be used as a cleavable linker to connect a gelator and a hydrophilic group. Photo-irradiation would lead to the
generation of the molecular gelator and the formation of a molecular hydrogel. The nitrobenzyl ester group could also be used as one part of hydrophobic capping group for short peptides to produce molecular hydrogelators. In this case, photo-irradiation would lead to the release of hydrophobic
anti-imflammatory drug of Naproxen and the gel-sol phase transition. The application of photocleavable group in molecular self-assembly would lead to photo-controllable self-assembly materials for controlled drug release, tissue engineering, and regenerative medicine.
研究领域:
生物材料学
·
药物递送
·
组织工程学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Coatings Technology and Research
·
2025
·
IF 2.8
Song Xiao,Zhou Chuanjiang,Yang Sijia,Liu Shengjie,Wu Zhaoqiang,Chen Hong
Polycarbonate (PC) substrates are widely used in our daily lives, but their inherent hydrophobicity makes them susceptible to changes in ambient temperature and humidity, which can cause fog that affects their light transmittance, limiting their use in applications that require high light transmittance, such as eyeglass lenses, automotive parts, and medical devices. In this study, P(HEAA- co -AEMA- co -BPA) transparent anti-fog coatings were prepared via one-step free radical copolymerization using N -(2-hydroxyethyl)acrylamide (HEAA), 2-aminoethylmethacrylate hydrochloride (AEMA), and 4-acryloyloyloxybenzophenone (BPA) as monomers. The hydrophilic HEAA monomer provides the coating with anti-fogging performance. The amino functional group in the AEMA segment reacts with the ester group on the surface of the PC substrate to form covalent urethane bonds during heat curing, and the hydrophobic BPA not only covalently binds with the PC substrate under UV irradiation but also prevents the anti-fogging performance of the anti-fog coating from being lost because of the absorption of too much water. The resulting transparent coatings have excellent anti-fogging effects in hot vapor tests and freeze–warm tests. Furthermore, the coatings exhibited good adhesion in the cross-cut tests. Quartz sand abrasion tests and wet cloth wiping tests also revealed that the coating has good abrasion resistance in both dry and wet states.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2022
·
IF 5.122
Feng Li,Mingyue Pan,Qi He,Qianhua Zhou,Qian Tang,Chengbin Gong
Multifunctional electrochromic materials are widely used in optoelectronic devices . Pyrene is a π-electron-rich group with fluorescence properties. Ester-functionalized pyrene derivatives potentially have interesting multifunctional properties such as electrochromic and electrofluorochromic characteristics. In this work, mono-, di-, tri-, and tetra-ester-substituted pyrene derivatives were synthesized, and the effects of the number of ester substituents on their photophysical, electrochemical, electrochromic, and electrofluorochromic properties were investigated. The number of ester substituents significantly affected these properties. An increase in the number of ester substituents on the pyrene caused red shifts in the absorption and emission spectra, a decrease in the driving voltage , and changes in the electrochromic colored states and electrofluorochromic performance. Mono-, di-, and tri-ester-functionalized pyrene derivatives showed good electrochromic properties, namely good switching stabilities, high optical contrasts, rapid responses, and high coloration efficiencies. Mono- and tri-ester-functionalized pyrenes gave good electrofluorochromic performances with reversible fluorescence quenching–fluorescence restoring between colored and bleached states during the electrochromic process. Ester-functionalized pyrene derivatives were successfully used in two functional digital displays with vivid colors. These results show that ester-functionalized pyrene derivatives with good electrochromic and electrofluorochromic properties are promising candidates for use in various applications, e.g., digital displays, organic electroluminescence displays, electronic shelf labels, energy-saving windows, and electronic paper.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Lubricants
·
2024
·Vol. 12
·期 12
·455
·
IF 3.1
Linghao Zhang,Qiuyu Shi,Xiangyu Ge
Electro-regulated friction is a widely adopted approach for reducing friction, with graphene oxide (GO) emerging as a promising lubricating additive due to its electro-responsive frictional behaviour. However, with the wide variety of functionalized GO additives available, each exhibiting distinct properties, it remains unclear which type demonstrates the most effective electro-regulated friction-reducing performance, limiting their broader industrial application. In this study, the frictional behaviour of three functionalized GO additives under electric stimulation was investigated along with an analysis of the corresponding worn surfaces. The findings reveal the role of functional groups in determining the tribological performance of functionalized GO additives and the mechanism of electric stimulation. Notably, the formation of ester groups during the friction process of GO-OH enhances the adsorption of GO additives onto steel surfaces, resulting in superior friction-reducing properties. Under lubrication with GO-OH additives, negative electric stimulation promotes the generation of ester groups and transitions the lubrication regime to mixed lubrication, thereby contributing to friction reduction. This work provides new insights into the tribological performance of functionalized GO additives and the mechanisms underlying their electro-regulated behaviours, laying a foundation for the design of GO additives with superior lubrication performance for practical engineering applications.
研究领域:
材料科学
·
机械工程
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 4
Zhang Xiao-Hui,Zhao Ya-Jun,Wang Can,Tang Shan
Incorporating a low density of ester units into the backbone of polyethylene materials enhances their sustainability and recyclability while maintaining the main material properties of polyethylenes. Here we report a new way to access degradable polyethylene materials with a low content of in-chain ester units via mechanochemical backbone editing. Initially, ester groups are incorporated as side groups through catalytic copolymerization of ethylene with a cyclobutene-fused lactone monomer (CBL), yielding polyethylene materials with high molecular weights and adjustable thermomechanical properties. Subsequent solid-state ball-milling treatment selectively introduces side-chain ester groups into the main chain of the polyethylene materials via force-induced cycloreversion of the cyclobutane units. Under acidic conditions, hydrolysis of the resultant polyethylene materials with in-chain ester units facilitates further degradation into oligomers.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yehan Yang,Mengxia Xu,Zhu Luo,Ruhui He,Jikai Xie,Shenglong Yang,Hu Chen,Huaibin Li
To address the compatibility challenges between polypropylene (PP) and poly(ethylene terephthalate) (PET), a long-chain-branched polypropylene compatibilizer featuring ester groups (LCB-PP-E) was synthesized from PP and pentaerythritol triacrylate (PETA), facilitated by the initiator dicumyl peroxide. The structure of LCB-PP-E was characterized by using infrared spectroscopy, rheology, and melt flow index analysis, while potential reaction mechanisms were discussed. The morphology of the blend was examined by scanning electron microscopy and Raman spectroscopy. The effects of LCB-PP-E on the thermodynamic and crystallization behavior of PP/PET blends were studied by dynamic mechanical analysis, differential scanning calorimetry, and polarizing microscopy. LCB-PP-E sampled at the reaction peak point exhibited a longer branched PP chain compared to that of LCB-PP-E obtained at the balance torque, facilitating better entanglement with PP macromolecules. Furthermore, the ester groups on LCB-PP-E engaged in transesterification reactions with the ester groups on the PET chains. The combined effects of these interactions effectively reduced the interfacial tension between the two phases, resulting in a decreased size of the dispersed PET phase and a more uniform distribution. Additionally, the introduction of LCB-PP-E significantly narrowed the crystallization and glass transition temperature difference between the phases. The enhanced compatibility led to an increase in elongation at break, demonstrating a transition of the blend from a brittle material to a ductile material. This compatibilization system shows substantial potential for high-quality applications in PP/PET recycled plastics.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Energy Material Advances
·
2024
·
IF 14.8
Hanyan Wu,Xinyang Chen,Changyong Zhao,Yingkang Tian,Xiaofei Yang,Runcang Sun,Xuejie Gao
Building lithium fluoride (LiF)-rich solid electrolyte interphases (SEIs) by the decomposition of fluorinated salts has been widely adopted to be effective to suppress lithium dendrite growth, thus prolonging the lifespan of fast-charging lithium metal batteries (LMBs). Nevertheless, the slow dissociation of LiF salts reduces both their utilization and the formation of inorganic SEI. Herein, cellulose acetate (CA) was incorporated into the electrolyte to create an inorganic-rich SEI through ester groups, where the lithiophilic oxygen atoms in the ester group (C═O) enhanced lithium-ion diffusion and anion dissociation rates. Therefore, rapid ion diffusion and dendrite-free anodes were achieved in the ester-based electrolyte with CA (named as CA-E). As a result, the lithium symmetric batteries with the CA-E electrolyte exhibited stable cycling performance for 5,000 h at a current density/capacity of 3 mA cm−2/1 mAh cm−2, while a short-circuiting was observed after ~450 h for the bare electrolyte. Benefiting from the rational design, lithium iron phosphate batteries with the CA-E electrolyte showed an excellent C-rate performance with a capacity of 100.7 mAh g−1 at the rate of 10 C. Moreover, a specific capacity of 110.3 mAh g−1 was maintained after 300 cycles at the rate of 6 C with a Coulombic efficiency of 99.87%. This work proposes a new approach to dendrite inhibitors for fast-charging LMBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Wen-Feng Ren,Jia-Bo Le,Jun-Tao Li,Yi-Yang Hu,Si-Yu Pan,Li Deng,Yao Zhou,Ling Huang,Shi-Gang Sun
Binders play a crucial role in the development of silicon (Si) anodes for lithium-ion batteries with high specific energy. The large volume change of Si (∼300%) during repeated discharge and charge processes causes the destruction and separation of electrode materials from the copper (Cu) current collector and ultimately results in poor cycling performance. In the present study, we design and prepare hydrogen-bonding cross-linked thiourea-based polymeric binders (denoted CMC-co-SN) in consideration of their excellent binding interaction with the Cu current collector and low cost as well. The CMC-co-SN binders are formed through in situ thermopolymerization of chain-type carboxymethylcellulose sodium (CMC) with thiourea (SN) in the drying process of Si electrode disks. A tight and physical interlocked layer between the CMC-co-SN binder and Cu current collector is derived from a dendritic nonstoichiometric copper sulfide (CuxS) layer on the interface and enhances the binding of electrode materials with the Cu current collector. When applying the CMC-co-SN binders to micro- (∼3 μm) (μSi) and nano- (∼50 nm) (nSi) Si particles, the Si anodes exhibit high initial Coulomb efficiency (91.5% for μSi and 83.2% for nSi) and excellent cyclability (1121 mA h g–1 for μSi after 140 cycles and 1083 mA h g–1 for nSi after 300 cycles). The results demonstrate that the CMC-co-SN binders together with a physical interlocked layer have significantly improved the electrochemical performance of Si anodes through strong binding forces with the current collector to maintain electrode integrity and avoid electric contact loss.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Science China-Technological Sciences
·
2025
·Vol. 68
·期 6
·1-16
·
IF 4.9
Yang Xuxuan,Zhang Qian,Nie Xiongfeng,Xu Ziyang,Liu Wenguang
The development of a meniscal substitute that conforms to the stringent requirements of high modulus, antiswelling, and shape compatibility continues to pose a significant challenge. Herein, the polycarbonate-based polyurethane (PCU) with a covalent adaptive network is constructed by introducing the Diels-Alder (DA) bonds into the hard segments of PCU as the dynamic covalent cross-linkage. On the one hand, the stability of DA bonds at low temperatures enables them to lock molecular chains within the hard domain in an aqueous environment, thus maintaining the high robustness of the resultant elastomer under physiological conditions. On the other hand, the incorporated DA bonds can be disrupted at high temperatures, facilitating the movement of the molecular chains through heating, thus allowing for the three-dimensional (3D) printing of the meniscus scaffold whose shape closely resembles that of the native tissue. The fabricated meniscus substitute is surgically implanted into the knee joints of rabbits for 12 weeks, with in-vivo outcomes illustratively showcasing its remarkable proficiency in mitigating cartilage surface degradation.
研究领域:
生物材料学
·
组织工程
·
再生医学
✓ 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）