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Mechanism study on the influence of surface properties on the synthesis of dimethyl carbonate from CO_(2)and methanol over ceria catalysts
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作者 Lei Dong Shengjie Zhu +4 位作者 Yangyang Yuan Xiaomin Zhang Xiaowei Zhao Yanping Chen Lei Xu 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第10期138-152,共15页
The direct synthesis of dimethyl carbonate(DMC)from CO_(2)and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes.Herein,a series of cerium oxide catalysts ... The direct synthesis of dimethyl carbonate(DMC)from CO_(2)and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes.Herein,a series of cerium oxide catalysts with various textural features and surface properties were prepared by the one-pot synthesis method for the direct DMC synthesis from CO_(2)and methanol,and the structure-performance relationship was investigated in detail.Characterization results revealed that both of surface acid-base properties and the oxygen vacancies contents decreased with the rising crystallinity at increasingly higher calcination temperature accompanied by an unexpectedly volcano-shaped trend of DMC yield observed on the catalysts.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)studies indicated that the adsorption rate of methanol is slower than that of CO_(2)and the methanol activation state largely influences the formation of key intermediate.Although the enhanced surface acidity-basicity and oxygen vacancies brought by low-temperature calcination could facilitate the activation of CO_(2),the presence of excess strongly basic sites on low-crystallinity sample was detrimental to DMC synthesis due to the preferred formation of unreactive mono/polydentate carbonates as well as the further impediment of methanol activation.Moreover,with the use of 2-cyanopyridine as a dehydration reagent,the DMC synthesis was found to be both influenced by the promotion from the rapid in situ removal of water and the inhibition from the competitive adsorption of hydration products on the same active sites. 展开更多
关键词 CeO_(2) Dimethyl carbonate surface property Methanol activation 2-Cyanopyridine
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Laser processing effects on Ti−45Nb alloy surface,corrosive and biocompatible properties
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作者 I.CVIJOVIĆ-ALAGIĆ S.LAKETIĆ +5 位作者 M.MOMČILOVIĆ J.CIGANOVIĆ Đ.VELJOVIĆ J.BAJAT V.KOJIĆ M.RAKIN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2533-2551,共19页
The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatme... The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy surface.The electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification treatment.Nevertheless,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm^(2),while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm^(2))and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide layer.Alloy cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also investigated.The Ti−45Nb alloy showed no cytotoxic effect.Moreover,cells showed improved viability and adherence to the alloy surface after the laser irradiation treatment.The highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 mJ.Results showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment. 展开更多
关键词 Ti−45Nb alloy laser surface scanning electrochemical properties BIOCOMPATIBILITY cell morphology
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Physico-Chemical and Nutritional Properties of a Food Broth Based on Nere (Parkia biglobosa)
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作者 Lassana Bamba Gervais Melaine M’Boh +5 位作者 N’Gbésso Amos Ekissi Kipré Laurent Séri Gnogbo Alexis Bahi Koffi Pierre Valery Niaba Allico Joseph Djaman Grah Avit Maxwell Beugre 《Food and Nutrition Sciences》 CAS 2024年第5期377-389,共13页
Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposin... Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposing to infections. This study of the physico-chemical and nutritional properties of a soumara-based food broth was carried out with the aim of promoting the consumption of organic broth made from nere seeds (soumara). That is to alleviate certain metabolic diseases, which is a matter of food safety, and also to limit the risk for the health about the consumption of some cooking stocks on the market. Methods: Several natural ingredients such as nere seeds (soumara), ginger, black pepper, parsley and garlic were used to create a nere-based stock. All these ingredients were freeze-dried and the powder obtained was used to make the broth, regarding their physical and chemical properties. Results: The broth had a good protein content of 17.41 ± 0.367 g/100g, a lipid content of 16.80 ± 0.08 g/100g and a fiber content of 8.66 ± 0.04 g/100g. In terms of nutritional values, the broth showed good levels of calcium 184.21 ± 0.09 mg/100g, potassium 50.04 ± 1.45 mg/100g and iron and zinc. In terms of antioxidant activity, the broth also showed good antioxidant activity. Conclusion: Regarding the properties of our food broth, whose composition is based on natural ingredients, could be recommended for consumption and, its properties, could play an important role in preventing and combating certain metabolic diseases. 展开更多
关键词 Food Broth Nere physico-chemical Properties NUTRITION Food Safety
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Physico-Chemical Properties of Soils from Diguel and Koudalwa Tchad,and Phytoremediation Potentials of Acasia and Kinkeliba Plants in Removing Cr and Cu from These Soils
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作者 Dieudonne Caleb Dahaina Jean Claude Doumnang Mbaigane +1 位作者 Bobet Ouanmini Cornelius Tsamo 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第5期165-177,共13页
The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these soils.Soil w... The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these soils.Soil was sampled from the tannery plant in Diguel and agricultural land around crude oil activities in Koudalwa.Soils were characterized by the following properties:pH,(Electrical Conductivity),TDS(Total Dissolved Solids),salinity,bulk density,OM(Organic Matter),nitrate,phosphate,clay,silt,sand,and textural class.The acasia and kinkeliba plants were used to decontaminate Cu and Cr from sample soils for 30 days period.The bulk density of all the soil samples from Kouldawa was higher compared to Diguil,ranging from 1.421 to 1.64 g/cm^(3)compared to 1.21 to 1.51 g/cm^(3)for Diguel.Most of the soils in Kouldawa are mineral soils,while those of Diguel are mostly mineral soil with some organics.Diguel soils are richer in nitrate(577.9 to 2,687.32 mg/kg in Diguel and 33.64 to 197.64 mg/kg in Kouldawa)and phosphate than soils from Kouldawa.Soils from the studied areas are not saline except for a subsurface soil in Diguel(salinity,4.21;EC,4.280 dS/m;TDS,3,040 mg/L).The highest amount of Cr and Cu removed by acasia is 78%and 53.12%compared to 73.8%and 52.21%by kinkeliba.Diguel soil can be very suitable for agriculture and Kouldawa soils for construction.Acasia and kinkeliba can be effectively used to decontaminate the studied soils from heavy metal pollution. 展开更多
关键词 SOIL physico-chemical properties PHYTOREMEDIATION heavy metals Tchad.
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Enhanced microwave absorption property of silver decorated biomass ordered porous carbon composite materials with frequency selective surface incorporation 被引量:4
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作者 Yi Liu Jingnan Qin +2 位作者 Linlin Lu Jie Xu Xiaolei Su 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第3期525-535,共11页
Porous carbon(PC)is a promising electromagnetic(EM)wave absorbing material thanks to its light weight,large specific surface area as well as good dissipating capacity.To further improve its microwave absorbing perform... Porous carbon(PC)is a promising electromagnetic(EM)wave absorbing material thanks to its light weight,large specific surface area as well as good dissipating capacity.To further improve its microwave absorbing performance,silver coated porous carbon(Ag@PC)is synthesized by one-step hydro-thermal synthesis process making use of fir as a biomass formwork.Phase compositions,morphological structure,and microwave absorption capability of the Ag@PC has been explored.Research results show that the metallic Ag was successfully reduced and the particles are evenly distributed inward the pores of the carbon formwork,which accelerates graphitization process of the amorphous carbon.The Ag@PC composite without adding polyvinyl pyrrolidone(PVP)exhibits higher dielectric constant and better EM wave dissipating capability.This is because the larger particles of Ag give rise to higher electric conductivity.After combing with frequency selective surface(FSS),the EM wave absorbing performance is further improved and the frequency region below-10 d B is located in8.20-11.75 GHz,and the minimal reflection loss value is-22.5 dB.This work indicates that incorporating metallic Ag particles and FSS provides a valid way to strengthen EM wave absorbing capacity of PC material. 展开更多
关键词 biomass carbon Ag@PC composite material frequency selective surface electromagnetic wave absorbing property
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Effect of dissolved components of malachite and calcite on surface properties and flotation behavior 被引量:2
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作者 Zhihao Shen Shuming Wen +4 位作者 Han Wang Yongchao Miao Xiao Wang Shengbing Meng Qicheng Feng 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第7期1297-1309,共13页
In general,malachite is recovered via sulfidization–xanthate flotation,although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite.This phenomenon occurs b... In general,malachite is recovered via sulfidization–xanthate flotation,although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite.This phenomenon occurs because the dissolved components of malachite and calcite affect the flotation behavior of both minerals.In this study,the effect of the dissolved components derived from malachite and calcite on the flotation behavior and surface characteristics of both minerals was investigated.Flotation tests indicated that malachite recovery decreased when the calcite supernatant was introduced,while the presence of the malachite supernatant increased the recovery of calcite.Dissolution and adsorption tests,along with zeta potential measurements,X-ray photoelectron spectroscopy,Fourier transform infrared spectrometry,and timeof-flight secondary ion mass spectrometry demonstrated that the Ca species in the calcite supernatant were adsorbed on the malachite surface,which hindered the interaction of Na2S with malachite,thereby resulting in the insufficient adsorption of sodium isoamyl xanthate(NaIX)on the surface of malachite.By contrast,the Cu species in the malachite supernatant were adsorbed on the calcite surface,and they provided active sites for the subsequent adsorption of Na_(2)S and NaIX. 展开更多
关键词 MALACHITE CALCITE dissolved components sulfidization-xanthate flotation surface properties
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Controlled Twill Surface Structure Endowing Nanofiber Composite Membrane Excellent Electromagnetic Interference Shielding
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作者 Dechang Tao Xin Wen +4 位作者 Chenguang Yang Kun Yan Zhiyao Li Wenwen Wang Dong Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期255-273,共19页
Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon ... Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon fabric were used as the matrix and filter templates,respectively.A Pva-co-PEMXene/silver nanowire(Pva-co-PE-MXene/AgNW,PM_(x)Ag)membrane was successfully prepared using a template method.When the MXene/AgNW content was only 7.4 wt%(PM_(7.4)Ag),the EMI shielding efficiency(SE)of the composite membrane with the oblique twill structure on the surface was 103.9 dB and the surface twill structure improved the EMI by 38.5%.This result was attributed to the pre-interference of the oblique twill structure in the direction of the incident EM wave,which enhanced the probability of the electromagnetic waves randomly colliding with the MXene nanosheets.Simultaneously,the internal reflection and ohmic and resonance losses were enhanced.The PM_(7.4)Ag membrane with the twill structure exhibited both an outstanding tensile strength of 22.8 MPa and EMI SE/t of 3925.2 dB cm^(-1).Moreover,the PM_(x)Ag nanocomposite membranes demonstrated an excellent thermal management performance,hydrophobicity,non-flammability,and performance stability,which was demonstrated by an EMI SE of 97.3%in a high-temperature environment of 140℃.The successful preparation of surface-twill composite membranes makes it difficult to achieve both a low filler content and a high EMI SE in electromagnetic shielding materials.This strategy provides a new approach for preparing thin membranes with excellent EMI properties. 展开更多
关键词 Twill surface structure MXene/AgNW Nanofiber membrane Electromagnetic interference Flexibility and mechanical properties
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Effects of laser energy on the surface quality and properties of electrodeposited zinc-nickel-molybdenum coatings
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作者 Tao Ni Zhaoyang Zhang +1 位作者 Yucheng Wu Shuai Yang 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2023年第3期18-26,共9页
As a substitute for toxic cadmium coatings in the aerospace industry,zinc-nickel coatings have excellent application prospects,and their properties can be improved by adding molybdenum.In this study,laser-assisted ele... As a substitute for toxic cadmium coatings in the aerospace industry,zinc-nickel coatings have excellent application prospects,and their properties can be improved by adding molybdenum.In this study,laser-assisted electrodeposition is used to improve the surface quality and properties of Zn–Ni–Mo coatings,with investigation of how laser energy in the range of 0–21.1μJ affects their element content,surface morphology,crystal phase,microhardness,residual internal stress,and corrosion resistance.The laser irradiation accelerates the electrodeposition,refines the grain size,improves the hydrogen adsorption,and reduces the residual tensile stress,and a laser energy of 15.4μJ gives the highest Ni and Mo contents and the lowest Zn content,as well as the optimum surface morphology,microhardness,residual internal stress,and corrosion resistance of the coating. 展开更多
关键词 ELECTRODEPOSITION Laser energy Zn-Ni-Mo surface quality Properties
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Effect of Fibre Size on Mechanical Properties and Surface Roughness of PLA Composites by Using Fused Deposition Modelling (FDM)
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作者 Aida Haryati Jamadi Nadlene Razali +1 位作者 Sivakumar Dhar Malingam Mastura Mohammad Taha 《Journal of Renewable Materials》 EI 2023年第8期3261-3276,共16页
Naturalfibre as a reinforcing agent has been widely used in many industrial applications.Nevertheless,several factors need to be considered,such as the size and weight percentage of thefibre used in binding.Using fused ... Naturalfibre as a reinforcing agent has been widely used in many industrial applications.Nevertheless,several factors need to be considered,such as the size and weight percentage of thefibre used in binding.Using fused deposition modelling(FDM),this factor was investigated by varying the size of naturalfibre as the responding variable with afixed weight percentage of kenaffibre.The process of modifying the naturalfibre in terms of size might increase the dispersion of kenaffibre in the polymer matrix and increase the adhesion bonding between thefibre and matrix of composites,subsequently improving the interfacial bonding between these two phases.In this paper,the effect offibre size was evaluated by performing the mechanical test,Scanning Electron Micrograph(SEM)to observe the morphology of the composites,and also by surface analysis.The surface roughness was visualised using a 3D profilometer and thefigure was illustrated as colour shading in the image.The composite withfibre size≤100μm displayed better tensile andflexural strength,compared to other sizes.In conclusion,by reducing the size of thefibre,the composites could develop high strength performance for industrial applications. 展开更多
关键词 Fibre size mechanical properties fused deposition modelling(FDM) surface analysis
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Preparation and tribological properties of surface modified Cu nanoparticles 被引量:17
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作者 杨广彬 柴单淘 +3 位作者 熊秀娟 张晟卯 余来贵 张平余 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期366-372,共7页
Cu nanoparticles surface-modified by dioctylamine dithiocarbamate (DTC8) were synthesized using a two-phase extraction route. The size, morphology and structure of resultant surface-capped Cu nanoparticles (coded a... Cu nanoparticles surface-modified by dioctylamine dithiocarbamate (DTC8) were synthesized using a two-phase extraction route. The size, morphology and structure of resultant surface-capped Cu nanoparticles (coded as DTC8-Cu) were analyzed by means of X-ray diffraction, transmission electron microscopy and infrared spectrometry. The tribological behavior of DTC8-Cu as an additive in liquid paraffin was evaluated with a four-ball machine, and the surface topography of the wear scar was also examined by means of scanning electron microscopy. Results show that Cu nanoparticles modified by DTC8 have a small particle size and a narrow size distribution. Besides, DTC8-Cu as an additive in liquid paraffin has excellent antiwear ability, due to the deposition of nano-Cu with low melting point on worn steel surface leading to the formation of a self-repairing protective layer thereon. 展开更多
关键词 copper nanoparticles surface modification tribological properties ADDITIVE PREPARATION
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Surface quality, microstructure and mechanical properties of Cu-Sn alloy plate prepared by two-phase zone continuous casting 被引量:1
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作者 刘雪峰 罗继辉 王晓晨 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第6期1901-1910,共10页
Cu-4.7%Sn (mass fraction) alloy plate was prepared by the self-developed two-phase zone continuous casting (TZCC) process. The relationship between process parameters of TZCC and surface quality of the alloy plate... Cu-4.7%Sn (mass fraction) alloy plate was prepared by the self-developed two-phase zone continuous casting (TZCC) process. The relationship between process parameters of TZCC and surface quality of the alloy plate was investigated. The microstructure and mechanical properties of the TZCC alloy plate were analyzed. The results show that Cu-4.7%Sn alloy plate with smooth surface can be obtained by means of reasonable matching the entrance temperature of two-phase zone mold and the continuous casting speed. The microstructure of the TZCC alloy is composed of grains-covered grains, small grains with self-closed grain boundaries, columnar grains and equiaxed grains. Compared with cold mold continuous casting Cu-4.7%Sn alloy plate, the room temperature tensile strength and ductility of the TZCC alloy plate are greatly improved. 展开更多
关键词 Cu-Sn alloy plate two-phase zone continuous casting surface quality grains-covered grains microstructure mechanical property
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A review on developing high-performance ZE41 magnesium alloy by using bulk deformation and surface modification methods 被引量:2
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作者 Subrat Kumar Baral Manjusha M.Thawre +1 位作者 B.Ratna Sunil Ravikumar Dumpala 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第3期776-800,共25页
Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,wh... Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,which is attributed to lower count of slip systems associated with the hcp crystal structure.To address these limitations,several new magnesium alloys and also many processing strategies have been developed and reported in the literature.ZE41 Mg is an alloy with significant quantities of zinc(Zn)and rare earth(RE)elements and has emerged as a promising material for aerospace,automotive,electronics,biomedical and many other industries.To make this alloy more competitive and viable,it should possess better mechanical and corrosion properties.Hence,the current paper reviews the effect of bulk mechanical processing on grain refinement,microstructural modification,and corresponding changes in the mechanical behaviour of ZE41Mg alloy.Further,the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented.This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys. 展开更多
关键词 ZE41 magnesium alloy Bulk deformation surface modification Mechanical properties WEAR Corrosion
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Surface modification of wollastonite by the mechano-activated method and its properties 被引量:9
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作者 Hao Ding Shou-ci Lu Gao-xiang Du 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2011年第1期83-88,共6页
Surface modification of wollastonite particles using titanate as a modification agent incorporated by simultaneous wet ultra-fine grinding in a laboratory stirred mill was investigated.The physical,physic-chemical and... Surface modification of wollastonite particles using titanate as a modification agent incorporated by simultaneous wet ultra-fine grinding in a laboratory stirred mill was investigated.The physical,physic-chemical and application properties of the modified wollastonite were measured and evaluated.The results showed that grinding intensity markedly influences the modification effect because of the mechano chemical effect.The hydrophilic surface of wollastonite was turned into a hydrophobic one after modification.The interaction between titanate and wollastonite under wet grinding circumstances was studied.It was suggested that physical adsorption and chemical adsorption of titanate coexisted on the wollastonite surface.The mechanical properties of polyethylene(PE) filled with the modified wollastonite powder were markedly improved. 展开更多
关键词 silicate minerals MODIFICATION surface properties ball milling FILLERS
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Bio-leaching effects of Leptospirillum ferriphilum on the surface chemical properties of pyrite 被引量:14
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作者 GU, Guohua SU, Lijun +2 位作者 CHEN, Minglian SUN, Xiaojun ZHOU, Hongbo 《Mining Science and Technology》 EI CAS 2010年第2期286-291,共6页
Leptospirillum ferriphilum cultured using different energy sources(either soluble ferrous ion or pyrite) changed the surface properties of pyrite.Cell adsorption,zeta-potential,hydrophobicty,FT-IR spectra and surface ... Leptospirillum ferriphilum cultured using different energy sources(either soluble ferrous ion or pyrite) changed the surface properties of pyrite.Cell adsorption,zeta-potential,hydrophobicty,FT-IR spectra and surface morphology were investigated.Adhesion of bacterial cells to the pyrite surface is a fast process.Furthermore,the adsorption of cells grown in pyrite is greater than of cells grown in soluble ferrous ion.The Iso-Electric Point(IEP) of pyrite treated with L.ferriphilum approaches that of the cells themselves.The contact angle of the pyrite surface was observed to decrease due to the surface formation of some hydrophilic substances during bio-leaching.Changes in pyrite surface properties after bacterial treatment support the idea that ferric ion plays an important role and that indirect bio-oxidation is the principal mechanism of pyrite bio-leaching. 展开更多
关键词 Leptospirillum ferriphilum PYRITE ADSORPTION bio-leaching surface properties
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Preparation and Surface Properties of Silicon-Containing Waterborne Polyurethane Functionalized with Fluorine-Containing Acrylate and Micro-Nano Silica 被引量:6
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作者 蔡棋 HUANG Jiemin +1 位作者 翁睿 LIU Shichen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第1期233-241,共9页
In order to prepare hydrophobic waterborne polyurethane coatings with better performances, the silicon-containing waterborne polyurethane(SiWPU) with functional chain extender hydroxyethyl acrylate(HEA) was prepar... In order to prepare hydrophobic waterborne polyurethane coatings with better performances, the silicon-containing waterborne polyurethane(SiWPU) with functional chain extender hydroxyethyl acrylate(HEA) was prepared first, and then a series of silicon&fluorine-containing polyurethane/acrylate(FSiPUA) emulsions were obtained with flourine containing acrylic monomer by seed emulsion polymerization, introducing micro-nano SiO2 into FSiPUA emulsion to make the final hybrid emulsion. The properties of Si WPU, FSiPUA and SiO2/FSiPUA were investigated by fourier transform infrared spectra(FTIR), transmission electron microscope(TEM), Scanning Electron Microscope(SEM) and some other analytical methods. The results revealed that FSiPUA emulsion particles possessed composite core-shell structure and FSiPUA films with suitable ratio performed better than Si WPU films in hardness, water resistance and solvent resistance. The SiO2/FSiPUA films with micro-nano dual roughness structure showed a water contact angle of 136° with good resistance to acid and alkali. 展开更多
关键词 waterborne polyurethane ACRYLIC SiO2 surface properties
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Effect of surface preparation on corrosion properties and nickel release of a NiTi alloy 被引量:6
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作者 MIAO Weidong MI Xujun XU Guodong LI Huachu 《Rare Metals》 SCIE EI CAS CSCD 2006年第z2期243-245,共3页
Surface preparation is potentially important to the corrosion and biomedical properties of NiTi shape memory alloys. The effect of surface preparation on corrosion properties and nickel release of a Ti-56 wt.%Ni alloy... Surface preparation is potentially important to the corrosion and biomedical properties of NiTi shape memory alloys. The effect of surface preparation on corrosion properties and nickel release of a Ti-56 wt.%Ni alloy has been studied. Surface of the NiTi coupons were prepared by four methods, namely, chemical etching, electropolishing, mechanical polishing and oxidizing, and then examined by corrosion test system. Furthermore, the Ni ion releases from NiTi samples with different surface preparations dipped in 1% HCl solution were analysed. Compared with the surface after chemical treatment, mechanical polishing and thermal oxidation, electropolished surface has better corrosion resistance and less nickel release for not only its lower surface roughness, but also the composition and property of its surface film. 展开更多
关键词 Ni Ti alloy surface preparation corrosion properties nickel realease
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Effect of rare earths surface treatment on tribological properties of carbon fibers reinforced PTFE composite under oil-lubricated condition 被引量:6
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作者 上官倩芡 程先华 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第4期584-589,共6页
The effect of rare earths (RE) surface treatment of carbon fibers (CF) on tribological properties of CF reinforced polytetrafluoroethylene (PTFE) composites under oil-lubricated condition was investigated. Exper... The effect of rare earths (RE) surface treatment of carbon fibers (CF) on tribological properties of CF reinforced polytetrafluoroethylene (PTFE) composites under oil-lubricated condition was investigated. Experimental results revealed that RE treated CF reinforced PTFE (CF/PTFE) composite had the lowest friction coefficient and wear under various applied loads and sliding speeds compared with untreated and air-oxidated composites. X-ray photoelectron spectroscopy (XPS) study of carbon fiber surface showed that, after RE treatment, oxygen concentration increased obviously, and the amount of oxygen-containing groups on CF surfaces were largely increased. The increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, stress could be effectively transmitted to carbon fibers; carbon fibers were strongly bonded with VITE matrix, and large scale rubbing-off of PTFE be prevented, therefore, tribological properties of the composite was improved. 展开更多
关键词 CF/PTFE composites surface treatment tribological property oil-lubrication rare earths
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IMPROVING THE SURFACE PROPERTY OF TC4 ALLOY BY LASER NITRIDING AND ITS MECHANISM 被引量:5
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作者 Y.L. Yang G.J. Zhao +1 位作者 D. Zhang C.S. Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2006年第2期151-156,共6页
The mixing technology of laser and heated nitrogen was applied to improve the surface hardness of titanium alloy ( TC4 ). The samples were nitrided with laser power density of 6.S × 10^6SW. cm^-2, the scanning ... The mixing technology of laser and heated nitrogen was applied to improve the surface hardness of titanium alloy ( TC4 ). The samples were nitrided with laser power density of 6.S × 10^6SW. cm^-2, the scanning speed varioas from 100 to 500mm ·min^-1. The nitrogen gas was pre-heated to 300℃ to accelerate the nitriding process. Some interested samples were tested with XRD method (X-ray diffraction) to analyze the composition of nitrides, and the surface hardness of HV was measured. The results show that TiN and Ti2N were formed on the surface of Ti alloy with proper nitriding parameters, but TiN is the main composition. The surface hardness increased by three times, which is from the original value of 269to 794kg·mm^-2. The mechanism of the mixing technology is considered mainly of the activation of nitrogen by laser power and the pre-heated process which accelerated the nitriding process. The nitridation process can be considered as six steps given in detail. The result by analyzing the mechanism of improving the surface property of TiAl alloy shows the improvement of surface property due to two factors: the first reason is the result of laser annealing, and the second one is the formation of TiN. 展开更多
关键词 laser nitridation surface property Ti alloy
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Physico-Chemical Properties of Flour, Starch, and Modified Starch of Two Rice Varieties 被引量:5
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作者 LIN Qin-lu XIAO Hua-xi +3 位作者 FU Xiang-jin TIAN Wei LI Li-hui YU Feng-xiang 《Agricultural Sciences in China》 CAS CSCD 2011年第6期960-968,共9页
The physical and chemical properties of the flours, starches, and modified starches of indica rice and japonica rice were investigated in this paper. Results showed that the swelling powers of flour, starch, and phosp... The physical and chemical properties of the flours, starches, and modified starches of indica rice and japonica rice were investigated in this paper. Results showed that the swelling powers of flour, starch, and phosphate starch [substitution degree (DS)=0.065] of japonica rice were significantly higher than those (DS=0.065) of indica rice. The transmittance of modified starches was highest; and that of flours was lowest. The pasting property investigated with rapid visco analyzer (RVA) indicated that the peak viscosity and breakdown value of paste with high swelling power were high. Furthermore, the effect of protein and amylose content on pasting property were investigated. The results of rheological properties determined using rheological rheometer showed that at the same temperature, the storage modulus (G′ of flour, starch, and modified starch of indica rice was higher than that of japonica rice. For each variety, the G′of flour was the highest, while the G′of modified starch was the lowest. 展开更多
关键词 RICE STARCH viscosity physico-chemical properties RHEOLOGY
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Study on the surface properties of surface modified silicone intraocular lenses 被引量:3
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作者 Gui-Qin Wang Han-Qing Gu and Xiu-Jun Peng 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第1期84-87,共4页
AIM: To prepare a new-type soft intraocular lens (IOL) that silicone intraocular lenses (IOLs) were modified by surface modification technique to assess IOLs biocompatibility. METHODS: With the technique of ion beam c... AIM: To prepare a new-type soft intraocular lens (IOL) that silicone intraocular lenses (IOLs) were modified by surface modification technique to assess IOLs biocompatibility. METHODS: With the technique of ion beam combined with low temperature and low pressure plasma, the surface characteristics of the IOLs including physical and optical properties were determined by the instruments of IOLs resolution, UV/VIS scanning spectrophotometer, contact angle measurement system, electron spectroscopy for chemical analysis (ESCA) and scanning electron microscope (SEM). RESULTS: The color of titanium (Ti) modified IOLs was light yellow and that of titanium nitride (TiN) modified IOLs was light brown. The absorptive degree of ultraviolet rays and the hydrophilicity of the surfaces of modified IOLs were increased, and appeared suitable chemical compositions. The resolution of unmodified and modified IOLs reached normal standard. The surfaces of unmodified and Ti-modified IOLs appeared uniform. The surfaces of TIN-modified IOLs presented fine porcelain structure. CONCLUSION: The optical properties of all IOLs and the surface morphology of the modified IOLs were not affected by modification processes. The surface properties of the modified IOLs were improved. 展开更多
关键词 SILICONE intraocular lenses surface modification technique surface property BIOCOMPATIBILITY
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