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High-precision and reliable thermal conductivity measurement for graphene films based on an improved steady-state electric heating method

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Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica 2025年第5期41卷 145-156页

作者： Lu, Jiahao Ming, Xin Liu, Yingjun Hao, Yuanyuan Zhang, Peijuan Shi, Songhan Mao, Yi Yu, Yue Cai, Shengying Xu, Zhen Gao, Chao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province Zhejiang University Hangzhou 310027 China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030032 China Center for Healthcare Materials Shaoxing Institute Zhejiang University Zhejiang Province Shaoxing 312000 China

The graphene film with high thermal conductivity has garnered considerable attention in recent years as an ideal material for dissipating heat in high-power electronic devices. Thermal conductivity is a crucial parameter for evaluating its fundamental performance. High-precision measurement holds significant importance for understanding its basic properties, fabrication optimization, and industrial applications. However, it is difficult to simultaneously achieve efficient, accurate, and reliable measurements with existing commercial thermal conductivity testing methods. The development of a convenient, high-precision, and reliable measurement approach remains a great challenge. Here, we introduce a thermal conductivity testing methodology with superior accuracy and excellent efficiency based on an improved steady-state electric heating method, refined through the optimization of heat transfer principles, experimental operation, and data analysis, supported by finite element simulation. The accuracy of measurements is affected by four factors: heat loss calibration, sample size, device design, and data treatment. The experimental results show that the heat loss caused by heat radiation and heat convection affects the temperature distribution and the measurements of the sample, which should be strictly controlled by sample size and temperature rise. Reasonable screening and preprocessing of data are also necessary to improve measurement accuracy. Through the comparative analysis of the temperature distribution and thermal conductivity measurements of samples under different conditions, we propose feasible operational guidance and a standardized testing protocol to minimize measurement error. The measurement error is less than 3.0%, and uncertainty is reduced to 0.5%. Simulation results confirm that the response time of this method is down to milliseconds, correlating well with the experiment, which can effectively improve test efficiency. Considering the combined meri

关键词： Finite element simulation Graphene film Steady-state technology Thermal conductivity

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POLYMERIZATION OF ALPHA,ALPHA-DISUBSTITUTED BETA-PROPIOLACTONES AND LACTAMS .7. STEREOREGULAR POLYMERS FROM OPTICALLY-ACTIVE LACTONES

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JOURNAL OF POLYMER science PART A-POLYMER CHEMISTRY 1978年第1期16卷 261-274页

作者： DHONDT, CG LENZ, RW Polymer Science and Engineering Program Chemical Engineering Department University of Massachusetts Amherst Massachusetts 01002

Optically active α-phenyl-ααethyl-β-propiolactone of high optical purity was prepared and polymerized by homogeneous anionic initiation to the isotactic polyester. The racemic and isotactic polymers had apparently different crystalline properties suggesting that the former may be syndiotactic or may crystallize with unit cells containing both R and S blocks. Similar attempts to prepare α-methyl-α-isopropyl-β-propiolactone of high optical purity were unsuccessful although a partially crystalline polymer was obtained from the racemic monomer.

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Active-layer evolution and （CH3NH3）3Bi2l9-based solar substrate efficiency improvement of cell on TiO2-deposited ITO

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Nano Research 2016年第10期9卷 2921-2930页

作者： Xinqian Zhang Gang Wu Zhuowei Gu Bing Guo Wenqing Liu Shida Yang Tao Ye Chen Chen Weiwei Tu Hongzheng Chen State Key Laboratory of Silicon Materials MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China Department of Chemical Engineering Xinjiang Agriculture University Urumqi 830052 China

We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass. The precursor solution concentration and substrate structure have been demonstrated to be critically important in the active-layer evolution of the MA3Bi2I9-based solar cell. This work successfully improved the cell efficiency to 0.42% （average： 0.38%） with the mesoscopic architecture of ITO/compact-TiOdmesoscopic-TiO2 （meso-TiO2）/ MA3Bi2I9/2,2＇,7,7＇-tetrakis（N,N-di-4-methoxyphenylamino）-9,9＇spiro-bifluorene （spiro-MeOTAD）/MoO3/Ag under a precursor concentration of 0.45 M, which provided the probability of further improving the efficiency of the BiB＋-based lead-free organic-inorganic hybrid solar cells.

关键词： methyl-ammonium bismuth （Ⅲ） iodide organic-inorganic hybridsolar cell TiO2-depostied indium tinoxide （FRO） substrate morphology and crystallinity precursor solution concentration

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Active Fischer-Tropsch synthesis Fe-Cu-K/SiO_2 catalysts prepared by autocombustion method without a reduction step

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Journal of Energy Chemistry 2018年第2期27卷 432-438页

作者： Suthasinee Pengnarapat Peipei Ai Prasert Reubroycharoen Tharapong Vitidsant Yoshiharu Yoneyama Noritatsu Tsubaki Program in Petrochemistry Faculty of ScienceChulalongkorn University Department of Applied Chemistry School of EngineeringUniversity of Toyama Department of Chemical Technology Faculty of ScienceChulalongkorn University

The purpose of this study was to prepare iron-based catalysts supported on silica by autocombustion method for directly using for Fischer-Tropsch synthesis（FTS） without a reduction step. The effect of different citric acid（CA）：iron nitrate（N） molar ratios and acid types on the FTS performance of catalysts were investigated. The CA：N molar ratios had an important influence on the formation of iron active phases and FTS activity. The iron carbide（FexC）, which is known to be one of the iron active phases, was demonstrated by the X-ray diffraction and X-ray photoelectron spectroscopy. Increasing the CA：N molar ratios up to 0.1 increased CO conversion of catalyst to 86.5%, which was then decreased markedly at higher CA：N molar ratios. An excess of CA resulted in carbon residues covering the catalyst surface and declined FTS activity. The optimal catalyst（CA：N molar ratio = 0.1） achieved the highest CO conversion when compared with other autocombustion catalysts as well as reference catalyst prepared by impregnation method, followed by a reduction step. The autocombustion method had the advantage to synthesize more efficient catalysts without a reduction step. More interestingly, iron-based FTS catalysts need induction duration at the initial stage of FTS reaction even after reduction, because metallic iron species need time to be transformed to FexC. But here, even if without reduction, FexC was formed directly by autocombustion and induction period was eliminated during FTS reaction.

关键词： Fischer-Tropsch synthesis Iron-based catalysts Autocombustion Iron carbide SiO2

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Improving Thermal-oxidative Aging Resistance of Styrene-butadiene Rubber by Antioxidant Loaded Silica Aerogel

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Chinese Journal of Polymer science 2024年第8期42卷 1198-1209页

作者： Xue-Fei Ping Yu Wang Lu Liu Fu-Yong Liu Hong-Wei He Pi Wang Wen-Wen Yu Qiang Zheng College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030032China Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310058China

The antioxidant N-isopropyl-N'-phenyl-p-phenylenediamine(4010NA)was dissolved in ethanol and impregnated into silica aerogel(SAG)via vacuum-pressure cycles,yielding composite particles(A-N)with enhanced sustained-release and reinforcing *** effect of A-N on the mechanical properties and thermal-oxidative aging resistance of styrene-butadiene rubber(SBR)vulcanizates was *** and BET assessments indicated that the loading efficiency of 4010NA in SAG reached 14.26%within ethanol's solu bility *** A-N into SBR vulcanizates significantly elevated tensile strength by 17.5%and elongation at break by 41.9%over those with fumed silica and ***,A-N notably enhanced the thermal-oxidative aging resistance of *** aging for 96 h at 100℃,the tensile strength and elongation at break of SBR with A-N sustained 70.09%and 58.61%of their initial values,respectively,with the retention rate of elongation at break being 62.8%higher than that of SBR with fumed silica and free *** study revealed that A-N composite particles significantly inhibited the crosslinking in SBR's molecular chains,reducing hardening and embrittlement during later thermal-oxidative aging stages.

关键词： Styrene-butadiene rubber Silica aerogel Loading modification Thermal-oxidative aging

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APPLIED POLYMERIZATION REACTION KINETICS

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INDUSTRIAL AND engineering CHEMISTRY 1970年第2期62卷 54-&页

作者： LENZ, RW Polymer Science and Engineering Program Chemical Engineering Department University of Massachusetts Amherst Mass. 01002 United States

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Chondrogenic and chondroprotective response of composite collagen I/II-hyaluronic acid scaffolds within an inflammatory osteoarthritic environment

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Biomaterials science 2025年 2025 May 12页

作者： Battistoni, Carly M. Munoz Briones, Javier Brubaker, Douglas K. Panitch, Alyssa Liu, Julie C. Davidson School of Chemical Engineering Purdue University West LafayetteIN47907 United States Weldon School of Biomedical Engineering Purdue University West LafayetteIN47907 United States Purdue Interdisciplinary Life Science Program Purdue University West LafayetteIN47907 United States Center for Global Health and Diseases Department of Pathology Case Western Reserve University ClevelandOH44016 United States Blood Heart Lung Immunology Research Center University Hospitals ClevelandOH44106 United States Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University AtlantaGA30332 United States

Inflammation plays a key role in cartilage damage that occurs in osteoarthritis (OA). However, in vitro assessments of tissue-engineered constructs for cartilage regeneration generally do not consider their performance in the presence of inflammation. In this work, the chondrogenic differentiation potential of mesenchymal stromal cells (MSCs) was evaluated in the presence of both chondrogenic factors and inflammatory cytokines, and cartilage formation, degradative response, and inflammatory response were characterized. The addition of cytokines reduced cartilage production, increased cell proliferation, and resulted in an increase in inflammatory markers. Incorporation of hyaluronic acid (HA) had little impact on both collagen fibril microstructure and mechanical properties, two gel properties known to affect cell response, and thus allows the work to probe the biological impact of HA without the confounding effect of these gel properties. Regardless of in vitro environment, HA did not change cartilage production. The inflammatory response was similar with or without HA in terms of IL-6 and IL-10 secretion whereas IL-8 production exhibited some correlation with HA concentration as observed via a linear regression model. Additionally, in the presence of cytokines, inclusion of HA statistically decreased the gene- and protein-level expression of matrix metalloproteinase-13 (MMP-13). Thus, when exposed to both chondrogenic growth factors and inflammatory cytokines within a chondrogenic-promoting collagen I/II blended hydrogel, chondrogenic differentiation of MSCs was limited by the inflammatory environment. These findings emphasize the importance of understanding how biomaterials affect cell responses within disease-relevant inflammatory environments. © 2025 The Royal Society of Chemistry.

关键词： Fiber bonding

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Mesoporous aluminosilicate from nanocellulose template: effect of porosity, morphology and catalytic activity for biofuel production

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Renewable Energy 2025年 250卷

作者： Jovita, Stella Melenia, Alvina Tata Santoso, Eko Subagyo, Riki Tamim, Rustam Asikin-Mijan, Nurul Holilah, Holilah Bahruji, Hasliza Nugraha, Reva Edra Jalil, Aishah Abdul Tehubijuluw, Hellna Ulfa, Maria Prasetyoko, Didik Sukolilo Surabaya60111 Indonesia Department of Chemical Sciences Faculty of Science and Technology Universiti Kebangsaan Malaysia UKM Bangi Selangor Darul Ehsan 43600 Malaysia Cibinong 169111 Indonesia Centre for Advanced Material and Energy Sciences Universiti Brunei Darussalam Jl. Tungku Link BE1410 Brunei Department of Chemical Engineering Faculty of Engineering Universitas Pembangunan Nasional "Veteran" Jawa Timur Surabaya60294 Indonesia Department of Chemical Engineering Faculty of Chemical and Energy Engineering Universiti Teknologi Malaysia UTM Johor Johor Bahru81310 Malaysia Centre of Hydrogen Energy Institute of Future Energy Universiti Teknologi Malaysia UTM Johor Johor Bahru81310 Malaysia Department of Chemistry Faculty of Mathematics and Natural Sciences Pattimura University Ambon97233 Indonesia Study Program of Chemistry Education Faculty of Teacher Training and Education Sebelas Maret University Jalan Ir. Sutami 36A Central Java Surakarta57126 Indonesia

Mesoporous aluminosilicate (Al-MS) with different morphology and porosity is synthesized using a combination of sol-gel and hydrothermal methods by controlling the ratio between P123 and nanocellulose (NCC). The role of NCC as templates is elucidated based on the transformation of Al-MS from rod-like morphology with hexagonal pores to uniform nanoparticles with intraparticle mesostructure at increasing NCC ratios. Increasing NCC concentration reduced the regularity of the mesopores. TEM analysis revealed a hexagonal pore arrangement for Al-MS and Al-MS (0.25). In contrast, Al-MS (1) with only NCC shows disordered mesostructure. Optimization of P123:NCC ratio enhances the Vmeso/Vmicro to reach the optimum value of ∼18.65, which is essential to enhance hydrocarbon yield. Al-MS (0.25) is the most active catalyst for deoxygenation (DO) of Calophyllum inophyllum oil, reaching 95.98 % conversion, 50.77 % liquid yield and 60.27 % selectivity towards n-(C15+17) hydrocarbon. In general, Al-MS (0.25) demonstrates outstanding performance owing to its good physicochemical characteristics and acidity. © 2025 Elsevier Ltd

关键词： Mesoporous materials

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ELASTOHYDRODYNAMICS OF BLADE COATING

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AICHE JOURNAL 1990年第4期36卷 587-597页

作者： PRANCKH, FR SCRIVEN, LE Coating Process Fundamentals Program Department of Chemical Engineering & Materials Science University of Minnesota Minneapolis MN 55455

Blade coating is the most common method of coating paper, and it is applied in coating magnetic suspensions and adhesives. Typically, the blade's upstream edge is clamped into a rigid holder so that the blade and substrate form a converging wedge. The translating substrate drags liquid into the wedge, where liquid forces develop and deflect the elastic blade, but it is loaded externally to counteract the deflection. Liquid dragged past the blade and thus the coating thickness depend on the elastohydrodynamic interaction among blade, liquid, and loading. Shell theory and lubrication flow theory describe the interaction by means of differential equations that are shown to be equivalent to Saita and Scriven's (1985) earlier formulation but that lead to a computationally more efficient analysis. Predictions computed agree with those of the earlier formulation and with experiments. Moreover, the new predictions illustrate effects of normal force loading and broaden the theory of blade coating.

关键词： Coating Techniques

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Effect of Carbon Particles with Different Topological Shape on the Rheological Behavior of PVA Aqueous Dispersion

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Chinese Journal of Polymer science 2022年第11期40卷 1402-1410页

作者： Qing-Sheng Ni Miao Du Guo-Rong Shan Yi-Hu Song Qiang Zheng State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China Institute of Zhejiang University-Quzhou Quzhou324000China Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China

Poly(vinyl alcohol)(PVA)is usually processed and used in a form of aqueous dispersion.A large number of inter-and intramolecular hydrogen bonds make it very difficult to obtain suitable rheological behavior for *** this study,carbon particles with different topological shapes were added into PVA aqueous dispersion to tune the steady and dynamic rheological *** results show that the zero-dimensional particles(carbon black,CB)increase monotonically the zero-shear viscosity of PVA dispersion,while the one-dimensional particles(carbon nanotubes,CNTs)make it first increase,and then decrease and rise again,like an N-shape,and the two-dimensional particles(graphene oxide,GO)can make it first decrease and then increase,exhibiting a *** is believed that the topological shape of the carbon particles brought about these *** zero-dimensional particles mainly act as physical crosslinking points due to their small *** at a certain content,both CNTs and GO can destroy the intermolecular hydrogen bonds between PVA chains because the PVA chains can twine around the slim CNTs and the large planar size of GO prevents the adsorbed PVA from forming hydrogen bond with other *** high hydroxyl value of carbon particle surface could strengthen this *** is expected that the viscosity of polymer dispersion can be regulated by particles with different topological shape and the surface characteristic,so as to widen the operable concentration range during preparing composite functional materials.

关键词： Topological shape Hydrogen bond Rheological behavior PVA aqueous dispersion

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