The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visibl...The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu2O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO4 dosage 8 g, NaOH dosage 1.6 g, temperature 80℃, 60 min for Cu2+ absorption, and 60 min for reaction. Under the optimum conditions, the Cu2O deposition ratio approached 30% and the nano-Cu2O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu2O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu2O particles. Excellent antibacterial property of nano- Cu2O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu2O-loaded paper was proven to be hydrophobic.展开更多
The surface modified nanocopper particles were prepared with chemical reduction method. The wear test was carried out on a T-11 ball-on-plate friction and wear tester made in Poland. The material of the upper sample w...The surface modified nanocopper particles were prepared with chemical reduction method. The wear test was carried out on a T-11 ball-on-plate friction and wear tester made in Poland. The material of the upper sample was GCr15 and the counterpart was AISI-1045 steel. The morphologies of the worn surfaces of the samples were observed by optical microscope and scanning electron microscope, while the element distributions on the worn surfaces were determined by means of electron microprobe analysis. As the results, a film mainly made of Cu is formed on the worn surface. The film on the surface of the still upper sample is thicker than that formed on the revolving counterpart. At the edge of the groove of the worn surface made by the milling before test there is Cu element observed obviously, but there is not any Cu element in the bottom of the groove. A possible action mechanism of the film is suggested. The friction movement can induce reactivity of the metal and continuously produce activation surface. It benefits the film formed by nano-Cu in lubricant on the worn surface. Hardness and modulus of nano-Cu films were successfully measured and analyzed by the nanoindentation instrument. The results show that the hardness and modulus of the films are lower than those of the initial surface.展开更多
A procedure for preparing a nanofluid that a solid-liquid composite material consists of solid nanoparticles with sizes typically of 1-100 nm suspended in liquid was proposed. By means of the procedure, Cu-H2O nanoflu...A procedure for preparing a nanofluid that a solid-liquid composite material consists of solid nanoparticles with sizes typically of 1-100 nm suspended in liquid was proposed. By means of the procedure, Cu-H2O nanofluids with and without dispersant were prepared, whose sediment pho-tographs and particle size distribution were given to illustrate the stability and evenness of suspension with dispersant. The viscosity of Cu-H2O nanofluid was measured using capillary viscometers. The mass fractions（w） of copper nanoparticles in the experiment varied between 0.04% and 0.16% with the temperature range of 30-70 ℃. The experimental results show that the temperature and SDBS concentration are the major factors affecting the viscosity of the nano-copper suspensions, while the effect of the mass fraction of Cu on the viscosity is not as obvious as that of the temperature and SDBS dispersant for the mass fraction chosen in the experiment. The apparent viscosity of the copper nano-suspensions decreases with the temperature increase, and increases slightly with the increase of the mass fraction of SDBS dispersant, and almost keeps invariability with increasing the mass fraction of Cu. The influence of SDBS concentration on the viscosity of nano-suspension was relatively large comparing with that of the nanoparticle concentration.展开更多
基金financial support from the National Natural Science Foundation of China, with grant No. 31770620
文摘The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu2O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO4 dosage 8 g, NaOH dosage 1.6 g, temperature 80℃, 60 min for Cu2+ absorption, and 60 min for reaction. Under the optimum conditions, the Cu2O deposition ratio approached 30% and the nano-Cu2O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu2O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu2O particles. Excellent antibacterial property of nano- Cu2O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu2O-loaded paper was proven to be hydrophobic.
文摘The surface modified nanocopper particles were prepared with chemical reduction method. The wear test was carried out on a T-11 ball-on-plate friction and wear tester made in Poland. The material of the upper sample was GCr15 and the counterpart was AISI-1045 steel. The morphologies of the worn surfaces of the samples were observed by optical microscope and scanning electron microscope, while the element distributions on the worn surfaces were determined by means of electron microprobe analysis. As the results, a film mainly made of Cu is formed on the worn surface. The film on the surface of the still upper sample is thicker than that formed on the revolving counterpart. At the edge of the groove of the worn surface made by the milling before test there is Cu element observed obviously, but there is not any Cu element in the bottom of the groove. A possible action mechanism of the film is suggested. The friction movement can induce reactivity of the metal and continuously produce activation surface. It benefits the film formed by nano-Cu in lubricant on the worn surface. Hardness and modulus of nano-Cu films were successfully measured and analyzed by the nanoindentation instrument. The results show that the hardness and modulus of the films are lower than those of the initial surface.
基金Funded by Guangdong Provincial Natural Science Foundation (No. 04105950)Specialized Research Fund for the Doctoral Program of Higher Education (No. 20050561017)Program for New Century Excellent Talents in University (No. NCET-04-0826)
文摘A procedure for preparing a nanofluid that a solid-liquid composite material consists of solid nanoparticles with sizes typically of 1-100 nm suspended in liquid was proposed. By means of the procedure, Cu-H2O nanofluids with and without dispersant were prepared, whose sediment pho-tographs and particle size distribution were given to illustrate the stability and evenness of suspension with dispersant. The viscosity of Cu-H2O nanofluid was measured using capillary viscometers. The mass fractions（w） of copper nanoparticles in the experiment varied between 0.04% and 0.16% with the temperature range of 30-70 ℃. The experimental results show that the temperature and SDBS concentration are the major factors affecting the viscosity of the nano-copper suspensions, while the effect of the mass fraction of Cu on the viscosity is not as obvious as that of the temperature and SDBS dispersant for the mass fraction chosen in the experiment. The apparent viscosity of the copper nano-suspensions decreases with the temperature increase, and increases slightly with the increase of the mass fraction of SDBS dispersant, and almost keeps invariability with increasing the mass fraction of Cu. The influence of SDBS concentration on the viscosity of nano-suspension was relatively large comparing with that of the nanoparticle concentration.
