LANGMUIR
·
2025
·
IF 3.9
Jingwen Zhao,Peng Zhu,Huapeng Zhang
A ternary polymer–solvent mixture has already been proposed to prepare surface porous films. However, the uncertainty of the formation mechanism of surface porous films and the multitude of influencing factors with unclear priorities lead to the failure to promote this method. Here, a surface-porous polystyrene (PS) film with a pore size of 0.6 μm was successfully prepared from a ternary PS/poly(ethylene glycol)–tetrahydrofuran (PEG–THF) mixture, using ultrasonic dissolution to provide a dispersion effect. The total polymer concentration, PEG molecular weight, PS/PEG mass ratio, dissolution temperature, and evaporation temperature can help to optimize surface porous structures. Based on the rheological behavior of the ternary PS/PEG–THF mixture and comparative experiments with the traditional dissolution method, the formation mechanism of surface porous structures has been revealed. After dissolution, the ternary mixture should be viewed as a two-phase dispersion, emphasizing the dispersion effect of the dissolution process. The formation of surface pores is derived from the transportation, arrangement, and evaporation of dispersed PEG–THF domains. Thus, the preparation of high-quality surface porous films through a ternary polymer dispersion mainly requires attention to two points: the dissolution and dispersion method and the solvent selection. To obtain submicron surface porous films, a synergistic effect of the two is required.
研究领域:
高分子科学
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材料工程
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Xiaowei Fang,Ze Wang,Wenli Song,Songgeng Li,Weigang Lin
The preparation of furans from catalytic conversion of corn stover is investigated in H 2 O–THF (tetrahydrofuran) co-solvent system, and the effects of Bronsted acids (H 2 SO 4 , HCl, HNO 3 ) combined with alkali metal cations (Li + , Na + , K + ) are studied systematically. It is found that the effect of individual acid in promoting the summary yield of 5-hydroxymethylfurfural (HMF) and furfural (FF) can be ordered as Cl − > SO 4 2− > NO 3 − . When combined with a salt, the anion effect can be ranked in SO 4 2− > Cl − > NO 3 − , both for the HMF yield and the summary yield of furans. Based on the best anion of SO 4 2− , the impacts of the combined cations can be finely ranked as Na + > K + > Li + . For the system with Cl − , it ranks in K + > Li + > Na + for the HMF yield or the summary yield of furans. The performance of NO 3 − is so poor that no liquid product can be detected when any alkali metal cations is combined with HNO 3 . The performance of H 2 SO 4 /Na 2 SO 4 is the best among 9 tested combined catalysts, and the yield of HMF and FF from corn stover conversion under optimized conditions are 76% and 81% respectively.
研究领域:
生物化学
·
可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Ke Wang,Armin Rezayan,Linqi Si,Yongsheng Zhang,Renfeng Nie,Tianliang Lu,Jianshe Wang,Chunbao Xu
Catalytic conversion of glucose to 5-hydroxymethylfurfural (HMF) is a highly desirable routine for producing value-added chemicals. Herein, by using glucose as carbon source to fabricate porous carbon support, SnCl4 and citric acid were selected for forming Lewis acidic/basic SnOx and Brønsted −COOH over support, respectively, bifunctional solid acid tin oxide/carbon catalysts were prepared by a hydrothermal-pyrolysis strategy. It is found that the acid density of SnOx/C could be tuned by adjusting SnCl4 dosage and pyrolysis temperature. In a H2O-NaCl/THF biphasic system, 92.1% glucose conversion and 84.1% HMF yield were achieved over an optimized 3.0-SnOx/C-500 catalyst at 180 °C for 2 h. This catalyst demonstrates excellent recyclability in this reaction for five times and is also versatile for one-pot transformation of cellulose to HMF with 39.9% yield. The superior performance of 3.0-SnOx/C-500 could be ascribed to its highly dispersed SnOx nanoparticles, a suitable ratio of Brønsted to Lewis acids, as well as accessible pore-structure of the catalyst.
研究领域:
化学工程
·
催化
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 29
·14985-14992
·
IF 3.708
Jiang Li,Dao-jun Ding,Lu-jiang Xu,Qing-xiang Guo,Yao Fu
A biphasic system consisting of THF and water was studied to achieve the integrated conversion of cellulose and hemicellulose in lignocellulosic biomass to levulinic acid. As compared to previous studies using GVL as solvent, the utilization of a lower boiling point solvent, THF, also achieves the simultaneous hydrolysis of C6 and C5 carbohydrates in lignocellulosic biomass, and the results of simultaneous hydrolysis are comparable. Furthermore, it offers an alternative operation procedure after the hydrolysis. A distillation process is not only used to achieve the effective separation of the solid residue from the desired products, but it also helps in the complete isolation of furfural and formic acid from levulinic acid. Consequently, the utilization of by-product formic acid in the hydrogenation of furfural to furfuryl alcohol is explored, and the process is achieved with both model substrates and the feed from the lignocellulosic biomass feedstock. The hydrolysis of furfuryl alcohol gave C5 carbohydrate-derived levulinic acid. We finally explored the integrated conversion with five biomass raw materials, and the total yield of levulinic acid was quite obviously promoted by the additional conversion of pentose.
研究领域:
化学工程
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生物化工
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Weidong Chen,Guotao Wu,Teng He,Zhao Li,Zaiping Guo,Huakun Liu,Zhenguo Huang,Ping Chen
Octahydrotriborates are potential hydrogen storage materials and chemical vapor deposition precursors to boride films. Their syntheses have been quite challenging, however. In this paper, an improved facile route for the preparation of unsolvated sodium octahydrotriborate (NaB 3 H 8 ), which is an important precursor to other octahydrotriborates and derivatives, is reported. The key steps in the synthesis involve dispersing Na finely in inert media and preparing fresh tetrahydrofuran (THF)·BH 3 at room temperature . High purity unsolvated NaB 3 H 8 can be obtained in tens of grams or more in one batch, depending on the reactor size. Using NaB 3 H 8 as the precursor, sodium dodecaborate (Na 2 B 12 H 12 ) has been successfully synthesized. Both octahydrotriborates and dodecaborates have been observed as intermediates during the thermal dehydrogenation of borohydrides , and their facile syntheses would facilitate mechanistic studies on the hydrogen storage of borohydrides , among other potential applications.
研究领域:
材料科学
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化学
·
氢存储
·
催化
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Fuquan Xiong,Hang Wang,Han Xu,Yan Qing,Zhiping Wu,Yiqiang Wu
The fabrication of nanospheres with tailored structure has attracted much attention in material applications. Herein we found that the food additive, butylated hydroxytoluene (BHT), was able to adjust the solid and hollow structure of lignin nanospheres. At BHT concentrations greater than 0.3 mg/mL in tetrahydrofuran (THF), the obtained lignin nanospheres displayed a hollow structure due to phase separation between THF and water caused by BHT molecules, while the lignin nanospheres obtained without adding BHT exhibited a solid structure. BHT and lignin molecules containing a high content of the carboxy group did not participate in the formation of the nanospheres. Increases in the water stirring and dropping speeds reduced the diameter of the nanospheres, while increasing the initial concentration of lignin and BHT resulted in an increase in nanospheres diameters. Moreover, the shell wall thickness and single hole size could be controlled by employing the concentration of BHT and lignin. This work provides novel insights into the preparation of lignin nanospheres with tunable structures.
研究领域:
材料科学
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纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Tian Xie,Yuanyuan Li,Mengjie Zhang,Li Wang,Yingchu Hu,Kun Yin,Suhua Fan,Hai Wu
A series fluorescent probes (TBM-C x ( x = 1, 4, 8)) were designed based on embedding various alkoxy chains on the electron donor of triphenylamine (TPA)-based dicyanovinyl (MT) compound with an electron-deficient benzothiadiazole (BTD) for sensitive, selective, and visualizing detection of cyanide in aqueous solution. Due to the nucleophilic addition of CN − , the intramolecular charge transfer (ICT) of these probes was inhibited by the destroyed conjugated structure, exhibiting excellent “turn-on” fluorescence response toward cyanide anion (CN − ) in tetrahydrofuran (THF). However, the alkoxy chains with different lengths embedded in TPA not only enhance the sensitivity and solubility, but also regulate the emission behavior from ICT to aggregation-induced emission (AIE) characteristics. The binding mechanism and AIE sensing performances between the probes and CN − have been investigated and compared in THF/water mixture by spectral tools and theoretical calculations. The results showed that the ICT-based TBM-C1 probe with methoxy chain showed significantly turn-on fluorescence response to CN − as low as 0.077 μM in THF/water solution at high water fraction (90 %). Due to the AIE sensing process, TBM-C1 was successfully employed to determine CN − in food and water samples, image CN − in living cells and BALB/c mice, and prepare test kits for visualizing cyanide.
研究领域:
化学
·
生物医学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Mingguang Zhu,Youzhen Zhuo,Kaicong Cai,Hongyu Guo,Fafu Yang
A novel perylene liquid crystal with diphenylacrylonitrile groups on 1,7-bay positions was synthesized in high yield. This highly decorated perylene bisimide showed the ordered hexagonal columnar liquid crystalline behaviour between 124.9 and 189.5 °C. Upon excitation of 480 nm, an attenuation of fluorescent intensity was observed with the increase of water fraction in THF/H 2 O mixtures. However, the fluorescence intensity enhanced dramatically and attained a maximum value at water fraction of 40% in THF/H 2 O systems when excited at 330 nm. The fluorescence intensity increased by 10 times and the pseudo Stokes shift achieved 251 nm. These phenomena were well elucidated by the AIE and FRET effect, which were supported by the investigation of fluorescence quantum yield and fluorescence lifetime .
研究领域:
材料科学
·
化学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Armin Rezayan,Ke Wang,Renfeng Nie,Tianliang Lu,Jianshe Wang,Yongsheng Zhang,Chunbao Charles Xu
Catalytic transformation of carbohydrates to bio-chemicals such as 5-Hydroxymethylfurfural (HMF) has become a hot research topic, but development of cost-effective/efficient catalysts and processes remains a challenge for industrial application. In this study, efficient bifunctional Sn/KIT-1/C catalysts with controllable acid sites were synthesized and applied for glucose-to-HMF conversion. Strong Lewis acid sites were introduced into the framework of disordered mesoporous silica by liquid-phase grafting of tin chloride, and Bronsted acid sites were generated by inserting carbon into the mesopores, followed by controlled oxidation of the carbon. Characterizations revealed that optimizing the amount of carbon source, and carbonization and oxidation temperature provided a proper amount and strength of acidity that could significantly catalyze glucose dehydration reaction to HMF with suppressed byproducts formation. The best catalyst Sn/KIT-1/C(75–400-300) demonstrated superior catalytic performance at 175 °C for 2 h under THF/H 2 O biphasic system, obtaining 78.4 ± 2.1% and 82.9 ± 2.4% HMF yield and selectivity, respectively. The high activity may be attributed to catalyst high surface area/porosity, and the presence of well-balanced amounts and strength of Lewis/Bronsted acid sites. The catalyst could maintain its excellent catalytic activity for five consecutive runs, suggesting the high physical–chemical stability of the catalyst. The results obtained in this work demonstrated that bifunctional metal-supported silica–carbon composites can be a promising catalyst for simple/complex carbohydrates conversion to HMF/bio-based chemicals.
研究领域:
催化
·
化学工程
·
材料科学
·
生物化学
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Jiajun Chen,Zhinan Fan,Chi Zhang,Huatian Duan,Li-Juan Fan
To detect neomycin, one of the common antibiotics in the environment and in food and which may pose harm to human health, a fluorescence sensing system based on an amphiphilic conjugated polyelectrolyte (CPE) was constructed. The CPE, PFPE-COONa, with poly[fluorenyl-alt-p-phenyleneethynylene] (PFPE) as the backbone and carrying four pendant hydrophilic carboxylate groups and two long hydrophobic alkoxyl chains in each repeat unit, was successfully synthesized. The photophysical study found that PFPE-COONa emission was solvent dependent, displaying a 58 nm red shift in wavelength and a nearly 150-fold enhancement in intensity for the emission maximum, by varying the ratios of the mixed solvent. Based on an understanding of the photophysics, the sensing condition was optimization to dissolve PFPE-COONa in the THF/H2O mixed solvent with a ratio of 1:1. The sensing system displayed excellent sensing performance toward neomycin at a neutral pH value. The blue-to-green fluorescence color change of the polymer solution, which can be clearly observed by the naked eye, upon around 0.7 μM of neomycin and the limit of detection (LOD) was calculated to be 0.78 nM. In addition, other possible interferents had no significant influence on the detection of neomycin. The mechanism study confirmed that the polymer aggregation, which induced strong electrostatic static interaction between the carboxylate groups of high density in the polymer and the dense positively charged primary amino groups in neomycin, was the main reason for such a visually fluorescent color change. This study provides a general strategy for the future design of sensing systems for organic pollutants.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Yabiao Pei,Weikang Zhu,Runfei Yue,Jie Yao,Xin Liu,Lianqin Wang,Junfeng Zhang,Yan Yin,Michael D. Guiver
Adjusting catalyst/ionomer agglomerate is crucial to a high-performance catalyst layer (CL), particularly for non-precious metal catalysts . As a sacrificial component, the solvent plays a vital role during the CL formation process and resulting microstructure, determining the performance of the anion exchange membrane fuel cells (AEMFCs). Here, solvent mixtures of isopropanol (IPA) and tetrahydrofuran (THF) are studied for the controllable construction of the Co/Fe–N–C CL. The results indicate that the aggregate state of the ionomers and catalysts and the final CL microstructure strongly depend on the ratio of IPA and THF. The CL prepared with IPA: THF = 1:2 (v/v) shows a homogeneous distribution of Co/Fe–N–C catalysts, embedded in the ionomer matrix, due to the fast volatilization and low viscosity of the catalyst ink. The Co/Fe–N–C CL with high moisture adsorption behavior and retention ability results in a high performance AEMFC with peak power density of 545.3 mW cm −2 at 80 °C. The obtained results can guide the rational design of microstructure in non-precious metal CLs for high-performance AEMFCs.
研究领域:
材料科学
·
化学工程
·
电化学
·
燃料电池技术
✓ 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）