INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2012
·
IF 2.237
Fang-fang Tong,Hong Xu,Jian Yu,Li-xiong Wen,Jun Zhang,Jia-song He
A series of poly(methyl methacrylate) (PMMA)/1-dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid ([C12MIM][PF6]) blends were prepared by melt blending. The compatibility of blends was verified by scanning electron microscopy and differential scanning calorimetry. The introduction of [C12MIM][PF6] decreased the glass transition temperature of the blends due to its plasticization effect and increased the diffusivity of CO2 without significantly affecting the CO2 solubility. These blends were foamed with supercritical CO2 as the blowing agent via a pressure-quenching process. The foaming conditions are divided into three regions according to the main morphological difference of foams. At relatively low temperatures and pressures, neat PMMA could not be foamed, while the addition of [C12MIM][PF6] facilitated the formation of cells. By increasing temperature or pressure, neat PMMA foams were obtained with wide cell size distribution, while the blend foams were formed with narrowed cell size distribution and increased cell size. At high temperatures and pressures, neat PMMA was foamed with narrow cell size distribution and high cell density, while the major effect of [C12MIM][PF6] was to increase the cell size. These results indicated that the plasticization effect and the low surface energy of [C12MIM][PF6] accounted for the differences on the cell morphology between neat PMMA and the blend foams.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
ChemNanoMat
·
2022
·Vol. 8
·期 10
·e202200269
·
IF 3.82
Ziye Guo,Huanhuan Yang,Qingyong Tian,Wenjie Ma,Qun Xu,Buxing Han
Graphical A template- and surfactant-free top-down strategy was developed to transform non-vdW bulk CeO 2 into 2D amorphous CeO 2− x nanosheets with defective structure for the first time by cleaving Ce−O covalent bonds with the assistance of supercritical CO 2 . The unique nanosheets show outstanding UV-vis adsorption and photoluminescence properties due to the disordered atomic structure and increased vacancy defects (F-centers). Two-dimensional (2D) non-van der Waals (non-vdW) amorphous nanomaterials have attracted much attention for optical, catalytic and biomedical applications owing to their rich dangling bonds and unsaturated coordination. CeO 2 , a typical non-vdW material, with amorphous 2D structure and intrinsic optical properties have rarely been prepared via a top-down method due to the lack of anisotropy in its 3D bonding network. Herein, we develop an environmentally-friendly top-down method to achieve ultrathin 2D amorphous CeO 2− x with controllable defects from bulk CeO 2 by utilizing supercritical CO 2 . The unique CeO 2− x nanosheets exhibit outstanding ultraviolet-visible adsorption and photoluminescence (PL) properties due to the disordered atomic structure and increased vacancy defects resulting from the cleavage of Ce−O covalent bonds and amorphization of CeO 2 . In addition, the defect-related emission mechanism of the visible PL for the as-prepared 2D CeO 2− x nanosheets has been proposed.
研究领域:
材料科学
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光学
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纳米技术
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产品关联
DOI
高影响因子
FOOD SCIENCE AND BIOTECHNOLOGY
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2021
·Vol. 30
·期 10
·1303-1312
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IF 2.391
Duan Di,Huang Yong,Zou Ying,He Bingju,Tang Ruihui,Yang Liuxia,Zhang Zecao,Su Shucai,Wang Guoping,Zhang Deyi,Zhou Chunhui,Li Jing,Deng Maocheng
Analytical method which combines electronic tongue technique and chemometrics analysis is developed to discriminate oil types and predict oil quality. All the studied Camellia oil samples from pressing, n -hexane extraction and supercritical CO 2 extraction (SCCE), were successfully identified by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Furthermore, multi factor linear regression model (MLRM) was established to predict oil quality, which are indicated by acid value (AV) and peroxide value (POV). The practical potential of e-tongue for the discrimination and assessment of Camellia oils has shown promising application in the characterization of Camellia oils in the oil quality evaluation.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yi Yang,Yongbin Wang,Bin Zhou,Qi Tang,Ben Pu,Jin Cui,Yan Liu,Weiqing Yang
Mo 2 Ti 2 C 3 T x , a double transition metals (DTM) MXene, has emerged as a novel promising material for a wide range of applications due to its distinctive physicochemical properties. However, the commonly used method for preparing Mo 2 Ti 2 C 3 T x directly employing hydrofluoric (HF) acid as an etchant, is not only hazardous but also time-consuming. Recognizing the exceptional solubility and ultra-fast mass transfer kinetics of supercritical CO 2 (SC-CO 2 ), we introduced an extremely rapid SC-CO 2 assisted etching method that dramatically reduced the etching duration by a factor of 64, from 96 h to 1.5 h, thereby successfully preparing Mo 2 Ti 2 C 3 T x . When served as an anode in lithium-ion batteries (LIBs), the Mo 2 Ti 2 C 3 T x electrode achieves a high reversible specific capacity of 380 mAh g −1 at a current density of 0.1 A g −1 , significantly outperforming pure DTM-MXene-based anodes in terms of most reported capacities. This work provided a promising and efficient method for the etching of DTM-MXene.
研究领域:
材料科学
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能源存储技术
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纳米材料合成
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产品关联
DOI
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 5
·
IF 2.504
Yucui Hou,Shuhang Ren,Muge Niu,Weize Wu
The selective hydrogenation of isophorone (3,5,5-trimethyl-2- cyclohexen-1-one) to produce 3,3,5-trimethylcyclohexanone (TMCH), an important organic solvent and pharmaceutical intermediate, is of significance in industry. However, the over-hydrogenation to produce the by-product 3,3,5-trimethylcyclohexanol causes issues. Up to now, it is still a challenge to hydrogenate isophorone to TMCH with high selectivity. In this work, we found that Lewis acids could inhibit the hydrogenation of C=O bond on isophorone, thus greatly improving the selectivity towards TMCH. In addition, added solvents like supercritical CO2 also had a positive impact on the selectivity. Both the conversion and selectivity could be increased to more than 99% when suitable Lewis acid and solvent were employed. Nevertheless, Lewis acid also exhibited some inhibition on the hydrogenation of the C=C bond of isophorone. Hence, a relatively weak Lewis acid, ZnCl2, is suitable for the selective hydrogenation.
研究领域:
化学工程
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催化化学
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产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2019
·
IF 3.021
Shuang Yang,Chuanxian Li,Fei Yang,Xiaoteng Li,Guangyu Sun,Bo Yao
For the pipeline transportation of waxy crude oil, pour point depressants (PPDs) have been developed and used to improve its flowability at low temperature. As supercritical CO2 (scCO2) flooding becomes a common technique to improve oilfield recovery, how the sensitivity of PPD changes due to the degassed crude oil treated by CO2 should be studied. In this work, the effect of scCO2 extraction on the performance of EVA in improving the flowability of Changqing degassed crude oil is investigated by means of a self-developed scCO2 treating equipment, SARA/HTGC analysis, SEM analysis, pour point test, rheological measurement, asphaltene precipitation test, particle size analysis, DSC test, and microscopic observation. The results show that without EVA addition, scCO2 extraction aggravates the flowability of the crude oil at low temperature. The scCO2 extraction extracts light components from asphaltene aggregates causing asphaltenes to precipitate, which inhibits the asphaltenes on playing a role as the natural PPD. As a result, it leads to the formation of smaller needle-like wax crystals with large amount, worsening the flowability of the crude oil. When the EVA is present, however, scCO2 extraction favors the functioning of EVA on improving the flowability of the crude oil at low temperature. The addition of EVA can slightly enhance the solubility of wax molecules thus decreasing the crude oil WAT to some extent, while can significantly change the morphology of precipitated wax crystals from small needle-like to agglomerated clusters, thus improving the flowability of the crude oil. Because of the synergistic effect of EVA and asphaltene aggregates after scCO2 extraction, a more compact EVA–asphaltene–wax ternary crystal structure will form thus further decreasing the pour point, elastic modulus, and equilibrium viscosity at low temperature.
研究领域:
石油工程
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化学工程
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DOI
高影响因子
Journal of CO2 Utilization
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2019
·
IF 5.189
Jingfu Jia,Xiaojing Liu,Kongyun Wu,Xue Zhou,Fahuan Ge
Nanocarriers of the stimuli-responsive mesoporous silica nanoparticles (MSNs) have exhibited great potential on target-specific and controlled-release drug delivery. However, it is still a challenge to load drugs into this promising nanocarriers because of its gated structure. In this study, we developed a method named gate-penetration by supercritical CO 2 (GPS) to successfully prepared zedoary oil loaded chitosan grafted MSNs (ZO@CS-MSNs). Quantitative analysis by high performance liquid chromatography demonstrated the composition ratio of six primary ingredients in zedoary oil remained constant after the drug loading process. Several process parameters of GPS were optimized, and the drug load of ZO reached 41.4 ± 1.2%. Morphology characterization by scanning electron microscope showed that ZO@CS-MSNs were spheres with diameter about 80 nm and a ‘gate’ structure was formed by chitosan on the surface of MSNs. Infrared and thermogravimetric analysis were performed to further confirm the structure of ZO@CS-MSNs. in vitro drug release test under different pH conditions indicated that ZO had a well pH-response release behavior, proving that ZO was transported into the inner channels of MSNs. The results state GPS is a promising way of high-efficacy and non-destructive to overcome the drug loading problems for stimuli-responsive MSN and further extend its application.
研究领域:
药剂学
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纳米医学
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材料科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
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2012
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IF 3.35
Cheng Zhang,Guodong Li,Yihan Wang,Fuying Cui,Jien Zhang,Qingshan Huang
In this work, 5-fluorouracil-loaded- poly( l -lactic)-polyethylene glycol/polyethylene glycol (5-FU-loaded-PLLA–PEG/PEG) nanoparticles were prepared using a novel reverse emulsion-solution enhanced dispersion by supercritical fluids (reverse emulsion-SEDS) technique in an effort to obtain an efficient drug delivery system . In the experiment, 5-FU and PEG were dissolved in water PLLA–PEG was dissolved in organic solution, the aqueous solution was added dropwise to the organic solution under magnetic stirring, a reverse emulsion was immediately formed. The reverse emulsion was dried by a SEDS process so that 5-FU-loaded-PLLA–PEG/PEG nanoparticles (5-FU-NPs) were obtained. The particle size, size distribution, surface morphology, and physical and chemical properties of the 5-FU-NPs were investigated by laser diffraction particle size analysis, scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA). The drug encapsulation efficiency (EE), drug loading (DL), in vitro release profile and pharmacokinetics of 5-FU-NPs in rat plasma were investigated by high-performance liquid chromatography (HPLC). The in vivo tumor inhibition effect, increase in lifespan and hepatotoxicity of placebo-NPs, 5-FU and 5-FU-NPs were determined using H22 tumor-bearing ICR mice. These results collectively suggest that 5-FU-NPs prepared using SEDS have potential anti-tumor applications as a controlled drug release dosage form without harmful drug toxicity .
研究领域:
药剂学
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生物医学工程
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肿瘤学
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产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Xin Sun,Caili Dai,Yongpeng Sun,Mingyong Du,Tao Wang,Chenwei Zou,Jiayuan He
Hydraulic fracturing has become an important stimulation technique for low/ultralow permeability reservoirs. Supercritical CO2 (SC-CO2), as a no water phase material of fracturing fluid, receives wide attention. Current researches on SC-CO2 fracturing fluid has mainly focused on its viscous properties and superiorities. However, little attention has been devoted to the interaction between SC-CO2 fracturing fluid and the oil reservoir during the fracturing process. Besides, in a low permeability reservoir, the wettability determines the oil recovery by imbibition, which is a main way to explore oil for a matrix. Therefore, it is crucial to study the wettability alteration on a low permeability oil reservoir introduced by SC-CO2 fracturing fluid. In this study, a contact angle goniometer was introduced to characterize the wettability alteration on low permeability cores by SC-CO2 fracturing fluid. Meanwhile, nuclear magnetic resonance T2 spectra, a scanning electron microscope, and a energy dispersive spectrometer were used to explain the mechanisms of wettability alteration and the adsorption of fracturing fluid was analyzed. In addition, spontaneous imbibition tests were conducted to definite the impact of wettability alteration on oil production. The results showed that the thickener in SC-CO2 fracturing fluid, fluid filter loss, and reservoir permeability were all responsible for wettability alteration on the core surface. With the increasing thickener contents and filter loss of fracturing fluid, cores turned to be intermediate and slightly water-wet from initial strongly water-wet, which was unfavorable for oil production.Comparatively low permeability cores which consist of more micro-small pores were more likely to make treated cores oleophilic, as well. Thickener adsorption was confirmed to be the main mechanism on wettability alteration by SC-CO2 fracturing fluid, which resulted in different pore surfaces, and thus a more oleophilic cores surface. On the basis of the results of spontaneous imbibition, strong lipophilicity cores corresponded to lower oil recovery, which illustrated that wettability alteration caused by SC-CO2 fracturing fluid was not favored for oil flow.
研究领域:
石油工程
·
地质学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Jian Ren,Jiantao Zhou,Yong Kong,Xing Jiang,Xiaodong Shen
The objective of this research was to develop new hydrophobic silica aerogel microspheres (HSAMs) with water glass and hexmethyldisilazane for oil adsorption. The effects of the hexmethyldisilazane concentration and drying method on the structure and organic liquid adsorption capacity were investigated. The hexmethyldisilazane concentration of the modification solution did not influence the microstructure and pore structure in a noteworthy manner, which depended more on the drying method. Vacuum drying led to more volume shrinkage of the silica gel microsphere (SGM) than supercritical CO2 drying, thus resulting in a larger apparent density, lower pore volume, narrower pore size distribution, and more compact network. Owing to the large pore volume and pore size, the HSAMs synthesized via supercritical CO2 drying had a larger organic liquid adsorption capacity. The adsorption capacities of the HSAMs with pore volumes of 4.04–6.44 cm3/g for colza oil, vacuum pump oil, and hexane are up to 18.3, 18.9, and 11.8 g/g, respectively, higher than for their state-of-the-art counterparts. The new sorbent preparation method is facile, cost-effective, safe, and ecofriendly, and the resulting HSAMs are exceptional in capacity, stability, and regenerability.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 29
·e54070
·
IF 3
Kai Wang,Chiyu Zhou,Yibo Zhou,Yijia Fan,Junkang Chen,Linghao Hui,Xinyuan Zhang,Jianbin Qin
High performance electromagnetic (EM) interference shielding composites are of high demand due to increasing EM wave radiation pollution. In this work, GO/NiNCs/PMMA microcellular foams with different GO/NiNCs gradient and 3D conductive filler framework were fabricated by thermal reduction and supercritical CO 2 foaming process. With the crosslink of 1D NiNCs and 2D GO sheets, GO/NiNCs framework with electrical conductivity varied from 1.15 × 10 −4 to highest 1.09 × 10 −1 S/m is fabricated, exhibiting absorption-dominated electromagnetic interference shieling effectiveness (EMI SE) of 53.62 dB and specific EMI SE of 48.44 dB g −1 cm 3 in X-band. The density of GO/NiNCs/PMMA microcellular foams achieved lowest value of 0.623 g/cm 3 . Moreover, the foams showed excellent thermal conductivity and compressive strength of 178.76 MPa, indicating excellent application potential in aerospace and electronic field. The thermoplastic polymer matrix also indicates great potential in recycle of the foam material.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Yueping Jiang,Yanhong Feng,Bo Lei,Huiting Zhong
A compounded medium of supercritical CO 2 , ethanol, and water (SEW) was used to extract lignin from eucalyptus fiber and the mechanism of the extraction was studied. Compared with the extraction method based on high-temperature ethanol (HTE), the lignin yield of the SEW method was 49.7% higher with higher average molecular weight. Physical and chemical synergies occurred during the extraction process. SEW compound medium penetrated eucalyptus fiber cell walls because of strong permeability, while the fast discharge of the compounded medium facilitated efficient lignin dissociation and removal. Carbonic acid formed from CO 2 and water under high temperature and pressure can provide an acidic environment to effectively degrade hemicellulose . Formaldehyde formed from CO 2 and ethanol in the process also prevented condensation of the extracted lignin fragments. The obtained lignin had high content of β-O-4 linkages and syringyl units.
研究领域:
林产化学与工业
·
生物质化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）