CATALYSIS TODAY
·
2018
·
IF 4.667
Dawang Chu,Chen Zhao
The effective and selective conversion of cellulose to valuable fuels and chemicals is highly attractive. In this paper, we prepared a catalyst with the adjacent surface Cu° and oxygen-deficient WO x (2 < x < 3) species by reduction of CuWO 4 precursor, and such catalyst coupled with Ni/activated carbon (AC) attained high yield (71 wt%) and good cycling performances in catalyzing one-step hydrothermal conversion of cellulose to ethylene glycol (EG), highly superior to the performances on physically mixed Ni/C, Cu/C and WO 3 . The increased Cu doping amounts led to a higher ratio of the lower valence state W (V or IV) to the high valence W(VI) as indicated by XPS, XRD, and TPR-H 2 analyses. The oxygen vacancies on the hydrogen-reduced CuWO 4 sample dramatically increased, probably due to the benefits from the substantial dissociated H• on the neighboring Cu° center. The EG yields from cellulose are shown to be proportional to the concentrations of oxygen vacancies on WO x , which catalyzes the important elementary retro-aldol step reaction via adsorbing C 6 sugar intermediates in a specific way. It is inferred that Cu introduction is mainly used to create more oxygen vacancies on the WO x surface that helps adsorbing oxygenates, while Ni fast hydrogenates of hydroxyacetaldehyde to EG and avoids coking, constructing a multi-functional synergistic catalytic process from converting of cellulose to EG in the high-temperature water
研究领域:
催化化学
·
生物质转化
·
绿色化学
·
材料化学
·
能源化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 45
·17328-17337
·
IF 4.569
Yan Zhu,Hongmei Qing,Wenbo Dong,Mingrong Dong,Tao Shen,Jian Cui
Copper zinc tin sulfide (Cu2ZnSnS4, CZTS) is attracting interest in photovoltaic applications due to its proper band gap, low cost and low toxicity. It has been found that two phases can be fabricated, i.e. kesterite and wurtzite CZTS structures. Though kesterite CZTS is proven to be thermodynamically stable, the free energy difference between kesterite and wurtzite CZTS is rather small. So, wurtzite CZTS can also stably exist under ambient conditions. Controlling the phase formation can expand the dimensions to optimize the performance of applications based on CZTS. In this study, we found that phase control can be achieved by simply using a mixed solvent of ethylene glycol and triethylenetetramine (TETA) in a two-stage heating process. It is found that the incorporation of the reductive solvent of TETA during the 1st heating process converts the phase of the precipitates from CuS (TETA poor) to Cu7S4 (TETA rich). In the subsequent 2nd heating stage, the phase of the final products is determined to be kesterite CZTS originating from CuS and wurtzite CZTS from Cu7S4, respectively. Thus, the key to control the phases of the final products is to control the chemical environment of Cu under Cu1+-rich or Cu2+-rich conditions in the fabrication process, which corresponds to the phase of the final products of wurtzite CZTS or kesterite CZTS, respectively. This summarized principle can not only be used to explain the previous versatile experimental results but also to guide the controlled synthesis of various phases of CZTS and CZTS-like materials in applications.
研究领域:
材料科学
·
无机化学
·
半导体材料
·
纳米科技
·
光伏材料
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Qijing Guo,Hao Yi,Feifei Jia,Shaoxian Song
Phase change materials (PCMs) offer significant advantages in energy conversion and storage by facilitating the storage and release of thermal energy during phase transition processes. However, challenges such as leakage during PCM phase transitions and poor light absorption properties have constrained their application in the field of photothermal energy storage. In this study, Montmorillonite (Mt) and molybdenum disulfide (MoS 2 ) has been used to design and synthesize hybrid aerogels (MoS 2 /Mt) boasting high mechanical strength and excellent photothermal conversion performance. These aerogels are then used to encapsulate polyethylene glycol (PEG) to prepare composite PCMs with outstanding solar-thermal conversion and storage performances. The results show that the synthesized MoS 2 /Mt-PEG composite PCMs exhibit high enthalpies of melting and solidification of 169.16 J/g and 170.78 J/g, respectively, while the aerogel supporting material has a high compressive modulus of 1.96 MPa. Moreover, the composite material displayed excellent thermal stability and leakage resistance after undergoing 30 melting-cooling cycles. Furthermore, the incorporation of MoS 2 imparted outstanding light absorption properties to the MoS 2 /Mt-PEG composite, resulting in a high light absorption and photothermal conversion-storage efficiency of 93.4 % and 96.47 %, respectively. Synthesized composite PCMs also demonstrate outstanding performance in solar-thermal-electricity conversion, achieving a voltage output of 458 mV under illumination conditions and maintaining a sustainable voltage output even after removing the light source. Thus, the composite PCMs prepared in this work can meet the requirements of high enthalpy, effective leakage prevention, efficient solar-thermal conversion and solar-thermal-electricity conversion performance, thereby presenting potential applications in practical solar energy collection, conversion, and storage.
研究领域:
材料科学
·
能源化学
·
纳米复合材料
·
热能存储
·
光热转换
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Hashim Sliman,Xue Dong,Tao Zhao
In recent years, increasing environmental awareness and human skin protection from harmful radiation of the sun has attracted attention amongst numerous researchers. Here, a simple strategy was developed to enhance the hydrophilicity and ultraviolet (UV) protection of polyethylene terephthalate (PET) knitted fabric surface via grafting green cowpea protein (CP) with gum arabic modified epoxy (GAE) as a cross-linking agent. Chemical grafting between pretreated PET and GAE as well as between GAE and CP improved the hydrophilicity and UV protection of PET knitted Fabric. The enhanced surface wettability was confirmed by the decreased water contact angle from 135° to zero °. Moreover, the UV protection factor rating of modified PET knitted fabric was higher, indicating that the modifier layer caused scattering and absorbance of UV light. This approach has shown promising results for improving hydrophilicity and UV protection with sustained mechanical durability of 7 washing cycles.
研究领域:
材料科学
·
纺织化学
·
表面工程
·
生物高分子
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功能纺织品
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·Vol. 143
·期 3
·1391-1395
·
IF 2.072
Kemin Wang,Yuhui Lu,Penghui Chen,Jingsong Shi,Hongning Wang,Qiang Yu
Benzophenone (BP) is a common initiator which is often used in the UV-curing production and related fields. However, the shortcomings such as toxicity, odor, and migration always limit the development of the traditional BP photoinitiator . Polymeric benzophenone photoinitiator (PEG-BP) was synthesized basing on polyethylene glycol (PEG), succinic anhydride , 4-hydroxybenzophenone and epichlorohydrin . The structure of PEG-BP was characterized by IR and 1 H NMR. The radiation absorption of PEG-BP was detected by UV spectrophotometer with the maximum absorption wavelength at 283 nm in acetonitrile solvent, undergone significant redshift corresponding to small molecule photoinitiator BP, thus enhanced the photosensitive efficiency of UV-curing system in the long wavelength region. Besides, PEG-BP has better water solubility than BP, thus could be used in both oil and aqueous solution. The obvious advantage of this initiator was the elimination of amine based hydrogen donors and to provide alternative hydrogen donors with easily availability and non-toxicity. The effects of molecular weights of PEG-BP, photoinitiator concentration, UV-radiation intensity and different monomers on photopolymerization kinetics were investigated in detail. The synthesized polymeric photoinitiators are attractive to be used as type II photoinitiators.
研究领域:
高分子化学
·
光化学
·
材料科学
·
功能材料
·
辐射固化技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 80
·76905-76914
·
IF 3.289
Liujie Zhang,Ying Kuang,Jia Liu,Zhilan Liu,Shiwen Huang,Renxi Zhuo
In this paper, a receptor-mediated liposomal drug delivery system (DDS) was developed aiming to deliver cisplatin (cis-diaminedichloroplatinum(II); CDDP) targeting the liver. Acetyl glycyrrhetinic acid (AGA) was chosen as the hepatic targeting ligand and acetyl glycyrrhetinic acid-poly(ethylene glycol)-stearate (AGA-PEG-ST) was synthesized. Anionic 5-cholestene-3-beta-ol-3-hemisuccinate (CHO-HS) was also synthesized. The liposomal CDDPs were prepared by employing these functional moieties with phosphatidylcholine (PC) at various ratios. Meanwhile, methoxypolyethylene glycol-stearate (MPEG-ST) with an analogous structure but without AGA was also prepared as a control. The particle sizes of AGA modified liposomes ranged from 120 nm to 180 nm and the zeta potentials were located between −39.7 mV and −3.18 mV. The liposomes had encapsulation percentages of 51.5–61.7% and a loading capacity of 23.2–26.7% for CDDP. The transmission electron microscopy (TEM) observations showed that the liposomes had spherical morphologies with homogeneous distribution. In vitro cytotoxicity of CDDP-loaded liposomes against HepG2 human liver cancer cells and A549 human lung epithelial carcinoma cells were evaluated by MTT assays. The results demonstrated that the introduction of AGA could enhance the cytotoxicity of liposomal CDDP against HepG2 cells but showed less significant impact on A549 cells. CLSM observation and FCM measurement further confirmed that AGA modified liposomes had a stronger affinity to HepG2 cells than that of liposomes without AGA. The tissue distribution of calcein in mice indicated that AGA modified liposomes resulted in higher accumulation in the liver than that of liposomes without the AGA ligand. These results demonstrated the promise of AGA decorated anionic liposomes for hepatic targeted delivery of cisplatin.
研究领域:
药剂学
·
肿瘤学
·
纳米医学
·
药物递送系统
·
肝病学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 15
·
IF 1.768
Mi Zhou,Kaiyue Liu,Xin Qian
A series of pH-temperature dual stimuli-responsive random copolymers poly[ N,N -dimethylaminoethyl methacrylate- co -poly(poly(ethylene glycol) methyl ether methacrylate][poly(DMAEMA- co -MPEGMA)] were synthesized by free radical polymerization. The supramolecular hydrogel was formed by pseudopolyrotaxane, which was prepared with the host-guest interactions between α-cyclodextrin (α-CD) and poly(ethylene glycol) (PEG) side chains. Fourier transform infrared (FT-IR), nuclear magnetic resonance ( 1 H NMR), and X-ray diffraction (XRD) confirmed the structures of the hydrogels. The pH-temperature dual stimuli responsive properties of the hydrogels were characterized by rheometer. Finally, the controllable drug release behavior of the hydrogel, which was used 5-fluorouracil (5-Fu) as the model drug, was investigated at different temperatures and different pH values. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43279.
研究领域:
高分子材料科学
·
药物递送系统
·
生物医学工程
·
智能响应材料
·
药剂学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 2
·846-852
·
IF 1.289
Hong Yu Yang,Xiu Mei Zhang,Li Jie Duan,Ming Yao Zhang,Guang Hui Gao,Hui Xuan Zhang
A series of environmental pH-responsive block copolymers PEG-polyurethane with tertiary amine groups in the main chain and free carboxyl groups in the side chain were synthesized, including poly(ethylene glycol) (PEG), 1,4-bis (hydroxyethyl) piperazine, 1,6-diisocyanato hexamethylene, and 2,2-dimethylolpropionic acid. The chemical structure, molecular weight, and pH-dependent capacity of pH-responsive PEG-polyurethane were examined by 1 H-NMR, FTIR, gel permeation chromatography (GPC), and an acid-base titration. Moreover, the fluorescent dye fluorescein isothiocyanate was conjugated with PEG-polyurethane by the similar polymerization method and the obtained polymer was measured by ultraviolet visible spectroscopy (UV-vis) and fluorescent spectroscopy. The results indicated that the pH-responsive PEG-polyurethane showed a pH-buffering phenomenon and fluorescent imaging in a range of pH values. As a result, we demonstrated its potential application for optical imaging; however, it is believed that more applications in the areas of biomedicine will be possible owing to its free carboxyl acid terminal residues in the stimuli-responsive polymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
生物材料
·
分子影像学
·
高分子化学
·
纳米医学
·
药物递送
·
生物传感器
·
转化医学
✓ 已验证
DOI
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2024
·Vol. 221
·期 16
·2400342
·
IF 1.9
Jian Cheng,Xin Liu,Weichang Kong,Qingzheng Lei,Zhiyu Yu,Dun Liu
The fabrication of flexible electronics has gained extensive attention due to the growing demand of flexible devices. Among various methods, laser direct writing technology has emerged as a promising approach due to its advantages of high processing accuracy and simplicity. This research focuses on the preparation of copper microelectrodes using laser-induced reduction of CuO nanoparticles (Cu NPs) on polyethylene terephthalate films. First, the influence of various parameters on the conductivity of the copper microelectrodes is investigated. Second, flexible copper microelectrodes with a minimum resistivity of 62.29 μΩ cm and an adhesion grade of 4B level are successfully fabricated. Building upon these results, a capacitive pressure sensor is developed with optimal sensitivity of 3.99 Pa −1 , good hysteresis of 3.99%, and response and recovery times of 1.2 and 1.3 s, respectively. Repeatability tests confirm the sensor's stability and fatigue resistance. This research provides valuable insights for the production of flexible sensors.
研究领域:
生物医学工程
·
柔性电子学
·
传感器技术
·
纳米材料
·
微纳加工
·
可穿戴设备
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Le Li,Rui-Ying Bao,Tao Gao,Zheng-Ying Liu,Bang-Hu Xie,Ming-Bo Yang,Wei Yang
Improving the physical properties of biobased polymers using bionanofillers is essential to preserve its biodegradability. This work presents a dopamine-induced functionalization of cellulose nanocrystals (CNCs) with polyethylene glycol (PEG), to enhance the crystallization, mechanical and barrier properties of poly( L -lactic acid) (PLLA) bionanocomposites. The effect of molecular weight of grafted PEG on the properties of PLLA is also studied. PEGylation of CNCs significantly enhance the crystallization of PLLA, especially for CNCs functionalized with PEG of lower molecular weight, which lead to balanced strength and ductility, and 66.4% reduction in the oxygen permeability coefficient at a low content of 0.5 wt %. Moreover, 168% improvement of ductility for PLLA can be obtained by CNCs functionalized with longer PEG chains. The surface functionalization of CNCs proposed here opens up a green avenue towards designing and fabricating fully bio-based, high-barrier and low-cost polymer nanocomposites for packaging applications.
研究领域:
高分子材料
·
纳米复合材料
·
生物基包装
·
材料科学
·
聚合物改性
·
结晶动力学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Deshan Cheng,Mantang He,Wenbin Li,Jihong Wu,Jianhua Ran,Guangming Cai,Xin Wang
Growing of ZnO nanoparticles on PET films without crystal seeding has been achieved by employing polydopamine as the anchor. The PDA layer was formed on the surface of PET film by the polymerization of dopamine. The PDA-PET was dipped into zinc precursors for hydrothermal growth of ZnO nanoparticles. Cluster-like ZnO nanoparticles were obtained and the special structure was affected by the growing time and zinc ion concentration. The surface morphology, structure and properties were characterized, and the functions including antimicrobial activity and UV protection of the ZnO-coated PET film were investigated. The developed facile hydrothermal approach without seeding will benefit the development of UV resistant and antimicrobial PET films.
研究领域:
材料科学
·
纳米技术
·
表面功能化
·
生物医用材料
·
高分子材料
✓ 已验证
DOI
高影响因子
POLYMER
·
2015
·
IF 3.562
Xue Jiang,Chun Feng,Guolin Lu,Xiaoyu Huang
A homopolymer strategy was developed to synthesize temperature and pH/CO 2 stimulus-responsive homopolymers. A new class of acrylamide monomers bearing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group were designed and prepared through Aza-Michael addition reaction followed by amidation with acryloyl chloride using amino group as a linkage to connect oligo(ethylene glycol), N,N -diethylaminoethyl, and polymerizable double bond groups together. Subsequently, the corresponding homopolymers containing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group in each repeated unit were prepared via RAFT polymerization with controlled molecular weights and relatively narrow molecular weight distributions . The lower critical solution temperature (LCST) of homopolymer was examined to be influenced by molecular weight, salt concentration, and pH value of aqueous solution. The LCSTs of homopolymers could be tuned in a wide temperature window by changing pH value of aqueous solution and it increased with the decrease of pH value. Particularly, CO 2 gas as a unique pH stimulus can also reversibly adjust the solubility of homopolymer without the addition of acids or bases.
研究领域:
高分子化学
·
智能材料
·
药物递送
·
生物医用材料
·
刺激响应材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）