Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydr...Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydrophobic or superhydrophilic,are extensively employed due to their superior anti-icing,drag reduction,enhanced boiling heat transfer,self-cleaning,and anti-bacterial properties depending on solid-liquid interfacial interactions.Laser-based techniques have gained popularity in recent years to create micro/nano-structured surface owing to their high flexibility,system precision,and ease for automation.These techniques create laser induced periodic surface structures(LIPSS)or hierarchical structures on substrate material.However,micro/nanostructures alone cannot attain the desired wettability.Subsequent modification of surface chemistry is essentially needed to achieve target extreme wettability.This review paper aims to provide a comprehensive review for both laser texturing techniques and the following chemistry modification methods.Recent research progress and fundamental mechanisms of surface structure generation via different types of lasers and various chemistry modification methods are discussed.The complex combination between the laser texturing and surface chemistry modification methods to decide the final wetting condition is presented.More importantly,surface functionalities of these surfaces with extreme wetting properties are discussed.Lastly,prospects for future research are proposed and discussed.展开更多
In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite ad...In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.展开更多
Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high a...Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high as 196 mg of S per gram of adsorbent was demonstrated. The influence of loading amount of Cu （II） and calcination temperature on adsorptive desulfurization was investigated. Test results revealed that the optimum loading amount of Cu （II） was 15%, and the calcination temperature was 150 ℃. The pyridine-FTIR spectroscopy showed that a certain amount of Lewis acid could contribute to the increase of adsorption capacity. Spectral shifts of the v（C-S） and v（Cu-S） vibrations were detected from the Raman spectra of the Cu （II） complex which was a reaction product of CuBr2 with DMS. According to the hybrid orbital theory and the complex adsorption reaction, the desulfurization of PM and DMS over the CuBr2 modified bentonite is ascribed to the formation of S-M （σ） bonds.展开更多
The capacities of natural and modified Brazilian bentonite samples as adsorbents to remove hexavalent metal chromium were investigated under several conditions in batch and column methods. The raw material, Ca-bentoni...The capacities of natural and modified Brazilian bentonite samples as adsorbents to remove hexavalent metal chromium were investigated under several conditions in batch and column methods. The raw material, Ca-bentonite, was modified by anchorament of 3-aminopropyltrietoxisilane （APS） and 3,2- aminoethylaminopropyltrimetoxisilane （AEAPS） in the surface of bentonite sample： This type of new occurrence of bentonite is suitable as a raw material for adsorption process. Adsorption behavior of three bentonite types was strongly depending on pH of adsorbate solution, contact time adsorbent/adsorbate, and initial concentration of Cr（VI）. The results were confirmed by column method and reveals that the adsorption process of materials accorded by the Redlich-Peterson, Sips, Dubinin-Radushkevich, and tang- muir isotherm models. The exothermic entbalpic values reflected a favorable energetic process for chro- mium ions anchored in the material surfaces. The negative Gibbs free energy results supported the spontaneity of three adsorption reactions with Cr（VI） ions.展开更多
Nitrogen-containing carbons were prepared by modification of activated carbons.The modified carbons were used as electrode materials with improved electrochemical performance.Precursor anthracite was activated by KOH(...Nitrogen-containing carbons were prepared by modification of activated carbons.The modified carbons were used as electrode materials with improved electrochemical performance.Precursor anthracite was activated by KOH(KOH:anthracite= 1:1), modified by melamine or urea and then treated at 1173 K to obtain the modified carbons.The porous structure, the chemical composition and the electrochemical characteristics of the carbons were investigated by nitrogen sorption, XPS and electrochemical methods respectively.Electrochemical experiments were performed in an organic electrolytic solution of 1 M(C2H5)4NBF4/PC.The samples modified by the different methods showed differences in chemical composition that introduced varying degrees of electrochemical performance enhancement.The presence of nitrogen enhanced the electron donor properties and the surface wettability of the activated carbons:this ensured a sufficient utilization of the exposed surface for charge storage.展开更多
In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners ...In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners with different surfactant dosages and constituents were synthesized through intercalation reaction between sodium montmorillonite(NaM MT) and quaternary ammonium surfactants in aqueous solvents. The lubricating greases were prepared with the resulting organoclays, while the penetration and oil separation of lubricating greases were evaluated, respectively. The surface modification process of montmorillonite(MMT) was analyzed and the thickening mechanism of OMMT was discussed in this study. The experimental results showed that, with an increasing amount of surfactant, the basal spacing between the clay platelets was increasing and the structure of modifier molecules layer in the interlayer was changing from lateral bilayer to paraffin-type bilayer. The optimal properties of lubricating greases were achieved, when the structure of surfactant molecules loaded in the interlayer was the paraffin-type monolayer, which meant that the dosage of modifier was equal to 120—140 mmol/(100g). Meanwhile, it was found that the thickening performance, colloid stability, anti-wear and friction-reducing performance of lubricating greases were improved, when the surfactants were mixed with octadecyl trimethyl ammonium chloride(OTAC) and hexadecyl trimethyl ammonium chloride(HTAC). And the optimum mole ratio of two surfactants is was 1:1.展开更多
ZnO nanoparticles with an average size of 125 nm were prepared via homogeneous precipitation method and were characterized by SEM.The products were surface-modified by the surfactant SDS.Surface-modified nano particle...ZnO nanoparticles with an average size of 125 nm were prepared via homogeneous precipitation method and were characterized by SEM.The products were surface-modified by the surfactant SDS.Surface-modified nano particles were added at a mass ratio of 1.0%,2.0%,3.0%,and 4.0%,respectively,in base oil and their friction and wear behaviors were evaluated on a MRS-10D type four-ball wear tester.After four-ball wear tests,the morphology of the rubbing surfaces was evaluated with metallographic microscope.It was revealed that the modified nano ZnO had excellent behavior for improving anti-wear property and friction coefficient,which could greatly reduce the friction of machine parts.展开更多
The surface modification on the AA6082 Al?Mg?Si aging-hardenable aluminum alloy was investigated by electricaldischarge alloying (EDA) process. Kerosene, used as a dielectric fluid, was pyrolytically decomposed into c...The surface modification on the AA6082 Al?Mg?Si aging-hardenable aluminum alloy was investigated by electricaldischarge alloying (EDA) process. Kerosene, used as a dielectric fluid, was pyrolytically decomposed into carbon for the formationof a self-lubricated carbide layer on the aluminum alloy surface during EDA process. Transmission electron microscopy (TEM)image found that the self-lubricated carbide layer was a multi-phase material with carbides and graphite. As a result, theEDA-modified aluminum alloy had a negligible wear rate of ~2?10?4 mg/m (c. f. ~1.1?10?2 mg/m for aluminum alloy substrate).Notably, a new characteristic was found that the EDA-processed carbide layer was a soft magnet, which improved theelectromagnetic interference (EMI) shielding performance of the alloy.展开更多
In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and...In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.展开更多
Bentonite has been proven to be effective in enhancing the membrane property of clay, by which landfill liners can have better barrier performance with regard to the migration of contaminants. In this work, 5% sodium ...Bentonite has been proven to be effective in enhancing the membrane property of clay, by which landfill liners can have better barrier performance with regard to the migration of contaminants. In this work, 5% sodium bentonite amended with locally available Fukakusa clay was utilized to evaluate the membrane behavior toward different kinds of ions： K, Na and Ca. The chemico-osmotic efficiency coefficient, co, was obtained in electrolyte solution with different concentrations of 0.5, 1, 5, 10, and 50 mmol/L. According to the results, solute type and ion valence have a significant effect on membrane behaviors. Additionally, co continually decreased as the Na and Ca concentrations increased, which is consistent with the Gouy-Chapman theory. The membrane behavior toward Na was similar to that toward K, according to the chemico-osmotic efficiency coefficient co. In the case of the divalent ion Ca, the membrane behavior was lower compared to monovalent ions Na and K at the same concentration. The mechanisms of the membrane performance change were discussed with the assistance of XRD patterns, free-swelling results and SEM images.展开更多
Modification and characterization of natural zeolite under some various methods for hydrocracking catalyst of waste lubricant to gasoline and diesel fractions have been conducted. Natural zeolite from Klaten was activ...Modification and characterization of natural zeolite under some various methods for hydrocracking catalyst of waste lubricant to gasoline and diesel fractions have been conducted. Natural zeolite from Klaten was activated using hydrothermal treatment at temperature 500 ℃ for 6 h （produced ZAAHd）, the ZA sample was treated with hydrothermal followed by Microwave （produced ZAAHdM）, the ZA sample was treated with HCI 3 N at temperature of 90 ℃ for 30 min （produced ZAAH）, the ZAAH sample was heated in to microwave （produced ZAAHM）, the ZAAHM was treated hydrothermal （produced ZAAHMHd）, the ZAAHMHd sample was heated in to microwave （produced ZAAHMHdM）, soaking of natural zeolit activated by HCl-microwave-hydrothermal-microwave in NH4NO3 1 N which was stirred using stirer at room temperature for 24 h （produced ZAAHMHdMN） and the ZAAHMHdMN sample was heated into microwave （ZAAHMHdMNM）. The heating process by microwave was conducted at 550 watt for 15 rain. Catalyst characterization involved determination of the number of total acid sites using gravimetric method with vapour adsorption of NH3 and pyridine, catalyst crystallinity by XRD （X-ray diffraction） and TO4 （T= Si and AI） site by infra red spectrophotometer （IR）. Hydrocracking of waste lubricants oil was performed in a fixed bed reactor of stainless steel at temperature of 450 ℃, H2 flow rate of 15 mL/min., feed/catalyst ratio of 5. Liquid products of the hydrocracking were analyzed using GC （gas chromatography）. The characterization results showed that various modification of natural zeolite increased acidity and dealumination degree of the catalysts. Products of the hydrocracking were liquid, coke, and gas fractions. Liquid products consisted of gasoline fraction （C5-C12）, diesel fraction （C12-C20）, and heavy oil fraction （〉 C20）.Thc conversion of liquid products was increased with the increase of catalyst acidity. The greatest liquid product conversion was produced by the ZAAHMHdMNM catalyst, i.e., 56.80%, with selectivity towards gasoline, diesel, and heavy oil fractions was 88.37%, 8.61% and 3.02%, respectively. The increase of catalyst acidity increased the selectivity of gasoline fraction.展开更多
It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe fri...It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe friction and wear.Fullerenol,a kind of highly water-soluble nanoparticle,was synthesized and then used to ameliorate the tribological properties of Si 3 N 4 sliding against Al 2 O 3 in pure water.With the addition of fullerenol,the running-in period was shortened from 30 min to 100 s at a speed of 250 mm/s.The speed threshold above which ultralow friction can be obtained in a short time was expanded from 450 mm/s to 80 mm/s.Meanwhile,the load-carrying ability of water film was increased.The role of fullerenol was discussed based on observation of the wear scar by an optical interferometer and XPS characterization of the tribo-film on the wear track.展开更多
基金Project(52105175)supported by the National Natural Science Foundation of ChinaProject(BK20210235)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(JSSCBS20210121)supported by the Jiangsu Provincial Innovative and Entrepreneurial Doctor Program,China。
文摘Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydrophobic or superhydrophilic,are extensively employed due to their superior anti-icing,drag reduction,enhanced boiling heat transfer,self-cleaning,and anti-bacterial properties depending on solid-liquid interfacial interactions.Laser-based techniques have gained popularity in recent years to create micro/nano-structured surface owing to their high flexibility,system precision,and ease for automation.These techniques create laser induced periodic surface structures(LIPSS)or hierarchical structures on substrate material.However,micro/nanostructures alone cannot attain the desired wettability.Subsequent modification of surface chemistry is essentially needed to achieve target extreme wettability.This review paper aims to provide a comprehensive review for both laser texturing techniques and the following chemistry modification methods.Recent research progress and fundamental mechanisms of surface structure generation via different types of lasers and various chemistry modification methods are discussed.The complex combination between the laser texturing and surface chemistry modification methods to decide the final wetting condition is presented.More importantly,surface functionalities of these surfaces with extreme wetting properties are discussed.Lastly,prospects for future research are proposed and discussed.
文摘In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.
基金financially supported by the National Natural Science Foundation of China(No.21276086)
文摘Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high as 196 mg of S per gram of adsorbent was demonstrated. The influence of loading amount of Cu （II） and calcination temperature on adsorptive desulfurization was investigated. Test results revealed that the optimum loading amount of Cu （II） was 15%, and the calcination temperature was 150 ℃. The pyridine-FTIR spectroscopy showed that a certain amount of Lewis acid could contribute to the increase of adsorption capacity. Spectral shifts of the v（C-S） and v（Cu-S） vibrations were detected from the Raman spectra of the Cu （II） complex which was a reaction product of CuBr2 with DMS. According to the hybrid orbital theory and the complex adsorption reaction, the desulfurization of PM and DMS over the CuBr2 modified bentonite is ascribed to the formation of S-M （σ） bonds.
基金MCT, CNPq, and CAPES for financial supports and fellowships
文摘The capacities of natural and modified Brazilian bentonite samples as adsorbents to remove hexavalent metal chromium were investigated under several conditions in batch and column methods. The raw material, Ca-bentonite, was modified by anchorament of 3-aminopropyltrietoxisilane （APS） and 3,2- aminoethylaminopropyltrimetoxisilane （AEAPS） in the surface of bentonite sample： This type of new occurrence of bentonite is suitable as a raw material for adsorption process. Adsorption behavior of three bentonite types was strongly depending on pH of adsorbate solution, contact time adsorbent/adsorbate, and initial concentration of Cr（VI）. The results were confirmed by column method and reveals that the adsorption process of materials accorded by the Redlich-Peterson, Sips, Dubinin-Radushkevich, and tang- muir isotherm models. The exothermic entbalpic values reflected a favorable energetic process for chro- mium ions anchored in the material surfaces. The negative Gibbs free energy results supported the spontaneity of three adsorption reactions with Cr（VI） ions.
基金Projects 50672025 and 50730003 supported by the National Natural Science Foundation of China
文摘Nitrogen-containing carbons were prepared by modification of activated carbons.The modified carbons were used as electrode materials with improved electrochemical performance.Precursor anthracite was activated by KOH(KOH:anthracite= 1:1), modified by melamine or urea and then treated at 1173 K to obtain the modified carbons.The porous structure, the chemical composition and the electrochemical characteristics of the carbons were investigated by nitrogen sorption, XPS and electrochemical methods respectively.Electrochemical experiments were performed in an organic electrolytic solution of 1 M(C2H5)4NBF4/PC.The samples modified by the different methods showed differences in chemical composition that introduced varying degrees of electrochemical performance enhancement.The presence of nitrogen enhanced the electron donor properties and the surface wettability of the activated carbons:this ensured a sufficient utilization of the exposed surface for charge storage.
基金financially supported by the Chongqing Construction Project of Innovation Teams in Colleges and Universities-Petroleum Products Application Engineering and Technology(Project No.KJTD201342)the Chongqing Project of Innovation Research by Postgraduates(Project No.CYB16130)
文摘In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners with different surfactant dosages and constituents were synthesized through intercalation reaction between sodium montmorillonite(NaM MT) and quaternary ammonium surfactants in aqueous solvents. The lubricating greases were prepared with the resulting organoclays, while the penetration and oil separation of lubricating greases were evaluated, respectively. The surface modification process of montmorillonite(MMT) was analyzed and the thickening mechanism of OMMT was discussed in this study. The experimental results showed that, with an increasing amount of surfactant, the basal spacing between the clay platelets was increasing and the structure of modifier molecules layer in the interlayer was changing from lateral bilayer to paraffin-type bilayer. The optimal properties of lubricating greases were achieved, when the structure of surfactant molecules loaded in the interlayer was the paraffin-type monolayer, which meant that the dosage of modifier was equal to 120—140 mmol/(100g). Meanwhile, it was found that the thickening performance, colloid stability, anti-wear and friction-reducing performance of lubricating greases were improved, when the surfactants were mixed with octadecyl trimethyl ammonium chloride(OTAC) and hexadecyl trimethyl ammonium chloride(HTAC). And the optimum mole ratio of two surfactants is was 1:1.
基金supported by Liaoning Provincial Office of Education for Innovation Team (Project number:2006T001)Liaoning Province of Key Laboratory Project (Project number:2008403001)
文摘ZnO nanoparticles with an average size of 125 nm were prepared via homogeneous precipitation method and were characterized by SEM.The products were surface-modified by the surfactant SDS.Surface-modified nano particles were added at a mass ratio of 1.0%,2.0%,3.0%,and 4.0%,respectively,in base oil and their friction and wear behaviors were evaluated on a MRS-10D type four-ball wear tester.After four-ball wear tests,the morphology of the rubbing surfaces was evaluated with metallographic microscope.It was revealed that the modified nano ZnO had excellent behavior for improving anti-wear property and friction coefficient,which could greatly reduce the friction of machine parts.
文摘The surface modification on the AA6082 Al?Mg?Si aging-hardenable aluminum alloy was investigated by electricaldischarge alloying (EDA) process. Kerosene, used as a dielectric fluid, was pyrolytically decomposed into carbon for the formationof a self-lubricated carbide layer on the aluminum alloy surface during EDA process. Transmission electron microscopy (TEM)image found that the self-lubricated carbide layer was a multi-phase material with carbides and graphite. As a result, theEDA-modified aluminum alloy had a negligible wear rate of ~2?10?4 mg/m (c. f. ~1.1?10?2 mg/m for aluminum alloy substrate).Notably, a new characteristic was found that the EDA-processed carbide layer was a soft magnet, which improved theelectromagnetic interference (EMI) shielding performance of the alloy.
基金the financial support from the Natural Science Foundation of Chongqing(Project No.cstc2014jcyj A90013)
文摘In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.
基金Projects(51179168,51308310)supported by National Natural Science Foundation of ChinaProject(LQ13E080007)supported by Zhejiang Provincial Natural Science Foundation of ChinaProject supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars(Chinese State Education Ministry)
文摘Bentonite has been proven to be effective in enhancing the membrane property of clay, by which landfill liners can have better barrier performance with regard to the migration of contaminants. In this work, 5% sodium bentonite amended with locally available Fukakusa clay was utilized to evaluate the membrane behavior toward different kinds of ions： K, Na and Ca. The chemico-osmotic efficiency coefficient, co, was obtained in electrolyte solution with different concentrations of 0.5, 1, 5, 10, and 50 mmol/L. According to the results, solute type and ion valence have a significant effect on membrane behaviors. Additionally, co continually decreased as the Na and Ca concentrations increased, which is consistent with the Gouy-Chapman theory. The membrane behavior toward Na was similar to that toward K, according to the chemico-osmotic efficiency coefficient co. In the case of the divalent ion Ca, the membrane behavior was lower compared to monovalent ions Na and K at the same concentration. The mechanisms of the membrane performance change were discussed with the assistance of XRD patterns, free-swelling results and SEM images.
文摘Modification and characterization of natural zeolite under some various methods for hydrocracking catalyst of waste lubricant to gasoline and diesel fractions have been conducted. Natural zeolite from Klaten was activated using hydrothermal treatment at temperature 500 ℃ for 6 h （produced ZAAHd）, the ZA sample was treated with hydrothermal followed by Microwave （produced ZAAHdM）, the ZA sample was treated with HCI 3 N at temperature of 90 ℃ for 30 min （produced ZAAH）, the ZAAH sample was heated in to microwave （produced ZAAHM）, the ZAAHM was treated hydrothermal （produced ZAAHMHd）, the ZAAHMHd sample was heated in to microwave （produced ZAAHMHdM）, soaking of natural zeolit activated by HCl-microwave-hydrothermal-microwave in NH4NO3 1 N which was stirred using stirer at room temperature for 24 h （produced ZAAHMHdMN） and the ZAAHMHdMN sample was heated into microwave （ZAAHMHdMNM）. The heating process by microwave was conducted at 550 watt for 15 rain. Catalyst characterization involved determination of the number of total acid sites using gravimetric method with vapour adsorption of NH3 and pyridine, catalyst crystallinity by XRD （X-ray diffraction） and TO4 （T= Si and AI） site by infra red spectrophotometer （IR）. Hydrocracking of waste lubricants oil was performed in a fixed bed reactor of stainless steel at temperature of 450 ℃, H2 flow rate of 15 mL/min., feed/catalyst ratio of 5. Liquid products of the hydrocracking were analyzed using GC （gas chromatography）. The characterization results showed that various modification of natural zeolite increased acidity and dealumination degree of the catalysts. Products of the hydrocracking were liquid, coke, and gas fractions. Liquid products consisted of gasoline fraction （C5-C12）, diesel fraction （C12-C20）, and heavy oil fraction （〉 C20）.Thc conversion of liquid products was increased with the increase of catalyst acidity. The greatest liquid product conversion was produced by the ZAAHMHdMNM catalyst, i.e., 56.80%, with selectivity towards gasoline, diesel, and heavy oil fractions was 88.37%, 8.61% and 3.02%, respectively. The increase of catalyst acidity increased the selectivity of gasoline fraction.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50805086 and 50730007)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant Nos. 51021064 and 20821003)the National Basic Research Program of China (973 Program) (Grant No.2011CB302100)
文摘It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe friction and wear.Fullerenol,a kind of highly water-soluble nanoparticle,was synthesized and then used to ameliorate the tribological properties of Si 3 N 4 sliding against Al 2 O 3 in pure water.With the addition of fullerenol,the running-in period was shortened from 30 min to 100 s at a speed of 250 mm/s.The speed threshold above which ultralow friction can be obtained in a short time was expanded from 450 mm/s to 80 mm/s.Meanwhile,the load-carrying ability of water film was increased.The role of fullerenol was discussed based on observation of the wear scar by an optical interferometer and XPS characterization of the tribo-film on the wear track.
