Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spect...Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.展开更多
New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food proce...New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food processing fields were summarized in the paper. The results showed that nano TiO2 is the most dynamic one in the new nano material study today, which will have a very important impact on our social economic develop- ment in future. The research and utilization will give people＇s lives enormous changes.展开更多
Concrete is one of the key component in the construction field.The importance of concrete is because of its strength and long lasting properties.The incorporation of nano materials in concrete helps to improve the cha...Concrete is one of the key component in the construction field.The importance of concrete is because of its strength and long lasting properties.The incorporation of nano materials in concrete helps to improve the characteristics of conventional concrete.Titanium dioxide(TiO_(2))is one such nanomaterial that helps to increase the performance of concrete by enhancing self-cleaning,anti-microbial and anti-bacterial activities.This paper briefly explains about the reaction of titanium dioxide nano particle N-TiO_(2) on cement materials which in turn changes the mechanical and physical properties of concrete against chemical,climatic changes and abrasion.The review presented here includes the features of titanium dioxide nano particles basically,its dosage in concrete,its impact on concrete on both fresh and hardened properties,photo catalytic effect and anti-microbial.This review explores the photo catalytic degradation of concrete enhanced with N-TiO_(2),which presents a promising method for improving the durability and sustainability of concrete structures.The addition of N-TiO_(2),recognized for its photo catalytic properties when exposed to UV light,has demonstrated potential in tackling various environmental and structural challenges associated with concrete.The paper provides a detailed analysis of the mechanisms involved in the photo catalytic process,the way N-TiO_(2) particles aid in breaking down pollutants(including organic compounds,NOx,and CO₂),and its contributions to self-cleaning,antimicrobial functions,and the degradation of harmful pollutants.展开更多
Modifed starch flms are gaining attention as biodegradable and sustainable materials in the food packaging industry.However,their inherent properties,including their brittleness and low antimicrobial and antioxidant c...Modifed starch flms are gaining attention as biodegradable and sustainable materials in the food packaging industry.However,their inherent properties,including their brittleness and low antimicrobial and antioxidant capacities,limit their extensive application.To address these shortcomings,in this study,a composite flm was developed using potato-modifed starch(PMS)as the base material,enhanced with konjac glucomannan(KGM),Pleurotus citrinopileatus polysaccharide(PCP),and nano titanium dioxide(nano TiO_(2)).Additionally,PCP and nano TiO_(2),which are bioactive components,were incorporated to improve the functional properties of the flms,promoting their application in food preservation.The optimal composition of the composite flms was determined through a fuzzy comprehensive evaluation,and the best performance was achieved with 10 g/L of PCP and 1.5 g/L of nano TiO_(2).These composite flms exhibited high mechanical strength,antimicrobial capacity,and antioxidant capacity while being noncytotoxic.The practical effcacy of the composite flms was verifed by applying them to preserve fresh-cut yams at room temperature,where they effectively delayed spoilage and maintained yam quality.This study demonstrates that PMS/KGM/PCP/nano TiO2 composite flms can signifcantly enhance the shelf life of fresh produce,providing a viable route for eco-friendly food preservation.展开更多
AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHOD...AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHODS： Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L COL at 37℃. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells. RESULTS： The Ce （Ⅳ）-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm^3 Ce （lV）-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures （apoptotic bodies）, agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones. CONCLUSION： Ce （Ⅳ） doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.展开更多
Concrete is among the most utilized and essential construction materials in terms of strengthening the structure.The use of natural aggregates can be reduced by using crumb rubber aggregates(RA)as a substitute.The use...Concrete is among the most utilized and essential construction materials in terms of strengthening the structure.The use of natural aggregates can be reduced by using crumb rubber aggregates(RA)as a substitute.The use of RA will reduce the expense on aggregate and help in creating a sustainable environment.Nanoparticles improve the microscopic structure of concrete by filling pores present in cement paste thus reducing the cement usage in the mix.Employing nano titanium dioxide(NT)in rubber concrete(RC)helps to improve its properties.The findings showed that RA significantly alters the characteristics of the concrete;at a 15%level of fine aggregate(FA)replacement,the workability and density of the concrete mixes dropped by up to 26.53%and 5%,respectively.Concrete's compressive,tensile,and flexural strengths decreased by 16.1%,5.52%,and 3.1%,respectively,as a result of adding RA.However,these negative effects were successfully offset by the addition of NT.Even while workability declined,density grew.The research shows that the use of NT in RC composites enhances corrosion resistance and durability,reduces porosity,and improves permeability.The research also suggests that NT helps to smoothen pores and microcracks in concrete,resulting in enhanced resistance to elements such as water and air.This study employs analysis of variance to evaluate the mechanical and durability characteristics of rubberized concrete composites.Microstructural investigation employing field emission scanning electron microscopy examines the interfacial transition zone,hydration products,and pore structure,offering insights into the influence of NT on concrete matrix.This study offers thorough,significant information on the application of NT nanoparticles as a green and efficient additive to enhance concrete performance,and it also presents potential for additional studies in this area of study.展开更多
Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differ...Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differential thermal analysis, and the phase and microstructure were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. The results indicated that the carriers were encapsulated by nano-TiO2 with a thickness of 300-450 nm. The main crystalline phase of TiO2 calcined at 650~C was anatase, and the average grain size was 8.3 nm. The FT-IR absorption bands at 955.38 cm1 suggested that new chemical bonds among Ti, O, and Si had formed in the composites. The photocatalytic （PC） activity of the composites was investigated un- der UV irradiation. Furthermore, the photodegradation kinetics of formaldehyde was investigated using the composites as the cores of an air cleaner. A kinetics study showed that the reaction rate constants of the gas-phase PC reaction of formaldehyde were k = 0.576 mg＇m3·min^-1 and K = 0.048 m3/mg.展开更多
A series of pure and Y3＋-doped TiO2 nanoparticles with high photocatalytic activities were prepared by a sol-gel method using tetra-n-butyl titanate as precursor.The as-prepared catalysts were characterized by X-ray ...A series of pure and Y3＋-doped TiO2 nanoparticles with high photocatalytic activities were prepared by a sol-gel method using tetra-n-butyl titanate as precursor.The as-prepared catalysts were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and diffuse reflectance spectroscopy（DRS）.The results indicated that yttrium doping could effectively reduce the crystalline size,inhibit the anatase-to-rutile phase transformation and surppress the recombination of the photogenerated electron-hole pairs.The DRS results showed that the optical absorption edge shifted to red direction owing to yttrium ion doping.The photocatalytic activities of samples were evaluated by the photodegradation of methyl orange（MO） aqueous solution under 300 W high pressure mercury lamp irradiation.Photodegradation results revealed that Y3＋ doping could greatly improve the photocatalytic activity of TiO2.In this experiment,the optimal dosage was 1.5 mol.% when samples were calcined at 773 K for 2 h,which caused a MO photodegradation rate of 99.8% under UV irradiation for 70 min.展开更多
In the present work,two types of novel nano additives,titanium sulfonate ligand/black phosphorus(TiLi/BP)and titanium dioxide/black phosphorus(TiCVBP)nanocomposites,were prepared.The tribological behavior of the steel...In the present work,two types of novel nano additives,titanium sulfonate ligand/black phosphorus(TiLi/BP)and titanium dioxide/black phosphorus(TiCVBP)nanocomposites,were prepared.The tribological behavior of the steel/steel friction pairs lubricated by polyalphaolefins type 6(PA06)containing the nanocomposites under boundary lubrication was studied.The worn surfaces were analyzed using modem surface techniques.The experimental results show that the rubbed surfaces became smooth and showed little wear with the addition of the nanocomposites.TiO_(2)/BP nanocomposites can significantly improve the lubricity of BP nanosheets under high contact stress.The synergistic roles of the load-bearing abilities and rolling effect of TiO_(2) nanoparticles,the slip induced by the BP with its layered structure,and the establishment of a tribofilm on the sliding interface are the basis of the tribological mechanisms.展开更多
The interest in nano-engineered cements basically brought by the demands on increasing the performance of concrete structures in challenging applications,such as extreme thermal,electrical,and electromagnetic environm...The interest in nano-engineered cements basically brought by the demands on increasing the performance of concrete structures in challenging applications,such as extreme thermal,electrical,and electromagnetic environments.Traditional cementitious materials lack technological capabilities regarding thermal conductivity,electrical resistivity,mechanical strength,and electromagnetic shielding.Such limitations prevent their application in highperformance and multifunctional concrete structures,which are increasingly required in modern construction.The highdimensional complexity of multivariable optimization of multiple properties makes most of the current approaches unsuitable,and so requires new ways to predict,model,and optimize the performance of such advanced materials.In the present contribution,we introduce a holistic approach to the optimization of nano-engineered cements composites incorporating epoxy resin,nano titanium dioxide,carbon nanotubes,and portland cement.Advanced techniques of machine learning used include random forest regressor for multi-output property prediction and eXtreme gradient boosting,an implementation of the gradient-boosting algorithm that proved particularly useful in multi-objective optimization,for electrical codes’thermal and mechanical properties.Bayesian optimization is also employed to decrease the experimental trials and fine-tune the processing parameters;high-dimensional input space is reduced using principal component analysis to attain optimal model performance.Graph neural networks are utilized for modeling structureproperty relations,and Gaussian processes serve as a surrogate model mimicking the outcome of finite element analysis simulation effectively reducing delays at the computational level.The model yields noteworthy improvements:resistivity decreases by 30%–40%,thermal conductivity increases by 25%–30%,and tensile strength increases by 15%–20%.These enhancements make nano-engineered cements composites highly promising for multifunctional applications such as vibration absorption and electromagnetic shielding,which presents the need for smart,high-performance concrete structures for advanced applications in construction.展开更多
基金Funded by the Natural Science Foundation of Hebei Province, China (No. E2008000537)the Foundation for Development of Science and Technology of Hebei Province, China (No. 07215156)the Open Research Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education, China (No. 2010412)
文摘Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.
基金Supported by Key Scientific and Technological Program of Henan Province (112102310424)
文摘New applications and research progress of nano titanium dioxide （TiO2） in coating, environmental protection, chemical industries, cos- metics industry, electronic industrial products, medicine, health and food processing fields were summarized in the paper. The results showed that nano TiO2 is the most dynamic one in the new nano material study today, which will have a very important impact on our social economic develop- ment in future. The research and utilization will give people＇s lives enormous changes.
文摘Concrete is one of the key component in the construction field.The importance of concrete is because of its strength and long lasting properties.The incorporation of nano materials in concrete helps to improve the characteristics of conventional concrete.Titanium dioxide(TiO_(2))is one such nanomaterial that helps to increase the performance of concrete by enhancing self-cleaning,anti-microbial and anti-bacterial activities.This paper briefly explains about the reaction of titanium dioxide nano particle N-TiO_(2) on cement materials which in turn changes the mechanical and physical properties of concrete against chemical,climatic changes and abrasion.The review presented here includes the features of titanium dioxide nano particles basically,its dosage in concrete,its impact on concrete on both fresh and hardened properties,photo catalytic effect and anti-microbial.This review explores the photo catalytic degradation of concrete enhanced with N-TiO_(2),which presents a promising method for improving the durability and sustainability of concrete structures.The addition of N-TiO_(2),recognized for its photo catalytic properties when exposed to UV light,has demonstrated potential in tackling various environmental and structural challenges associated with concrete.The paper provides a detailed analysis of the mechanisms involved in the photo catalytic process,the way N-TiO_(2) particles aid in breaking down pollutants(including organic compounds,NOx,and CO₂),and its contributions to self-cleaning,antimicrobial functions,and the degradation of harmful pollutants.
基金supported by the Shenyang Medical College Scientifc Research Innovation Fund(Nos.20182033 and 20191038),China。
文摘Modifed starch flms are gaining attention as biodegradable and sustainable materials in the food packaging industry.However,their inherent properties,including their brittleness and low antimicrobial and antioxidant capacities,limit their extensive application.To address these shortcomings,in this study,a composite flm was developed using potato-modifed starch(PMS)as the base material,enhanced with konjac glucomannan(KGM),Pleurotus citrinopileatus polysaccharide(PCP),and nano titanium dioxide(nano TiO_(2)).Additionally,PCP and nano TiO_(2),which are bioactive components,were incorporated to improve the functional properties of the flms,promoting their application in food preservation.The optimal composition of the composite flms was determined through a fuzzy comprehensive evaluation,and the best performance was achieved with 10 g/L of PCP and 1.5 g/L of nano TiO_(2).These composite flms exhibited high mechanical strength,antimicrobial capacity,and antioxidant capacity while being noncytotoxic.The practical effcacy of the composite flms was verifed by applying them to preserve fresh-cut yams at room temperature,where they effectively delayed spoilage and maintained yam quality.This study demonstrates that PMS/KGM/PCP/nano TiO2 composite flms can signifcantly enhance the shelf life of fresh produce,providing a viable route for eco-friendly food preservation.
文摘AIM： To investigate the apoptotic effect of photoexcited titanium dioxide （TiO2） nanoparticles in the presence of visible light on human hepatoma cell line （Bel 7402） and to study the underlying mechanism. METHODS： Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L COL at 37℃. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells. RESULTS： The Ce （Ⅳ）-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm^3 Ce （lV）-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures （apoptotic bodies）, agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones. CONCLUSION： Ce （Ⅳ） doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.
文摘Concrete is among the most utilized and essential construction materials in terms of strengthening the structure.The use of natural aggregates can be reduced by using crumb rubber aggregates(RA)as a substitute.The use of RA will reduce the expense on aggregate and help in creating a sustainable environment.Nanoparticles improve the microscopic structure of concrete by filling pores present in cement paste thus reducing the cement usage in the mix.Employing nano titanium dioxide(NT)in rubber concrete(RC)helps to improve its properties.The findings showed that RA significantly alters the characteristics of the concrete;at a 15%level of fine aggregate(FA)replacement,the workability and density of the concrete mixes dropped by up to 26.53%and 5%,respectively.Concrete's compressive,tensile,and flexural strengths decreased by 16.1%,5.52%,and 3.1%,respectively,as a result of adding RA.However,these negative effects were successfully offset by the addition of NT.Even while workability declined,density grew.The research shows that the use of NT in RC composites enhances corrosion resistance and durability,reduces porosity,and improves permeability.The research also suggests that NT helps to smoothen pores and microcracks in concrete,resulting in enhanced resistance to elements such as water and air.This study employs analysis of variance to evaluate the mechanical and durability characteristics of rubberized concrete composites.Microstructural investigation employing field emission scanning electron microscopy examines the interfacial transition zone,hydration products,and pore structure,offering insights into the influence of NT on concrete matrix.This study offers thorough,significant information on the application of NT nanoparticles as a green and efficient additive to enhance concrete performance,and it also presents potential for additional studies in this area of study.
基金financially supported by the National Natural Science Foundation of China (No. 50708037)the National Science Fund for Excellent Young Scholars of China (No. 51522402)+1 种基金the Science and Technology Research Projects in Zhengzhou (No. 141PPTGG388)the National Innovation and Entrepreneurship Training Program of the Undergraduate (No. 201610078034)
文摘Diatomite-based porous ceramics were adopted as carriers to immobilize nano-TiO2 via a hydrolysis-deposition technique. The thermal degradation of as-prepared composites was investigated using thermogravimetric-differential thermal analysis, and the phase and microstructure were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. The results indicated that the carriers were encapsulated by nano-TiO2 with a thickness of 300-450 nm. The main crystalline phase of TiO2 calcined at 650~C was anatase, and the average grain size was 8.3 nm. The FT-IR absorption bands at 955.38 cm1 suggested that new chemical bonds among Ti, O, and Si had formed in the composites. The photocatalytic （PC） activity of the composites was investigated un- der UV irradiation. Furthermore, the photodegradation kinetics of formaldehyde was investigated using the composites as the cores of an air cleaner. A kinetics study showed that the reaction rate constants of the gas-phase PC reaction of formaldehyde were k = 0.576 mg＇m3·min^-1 and K = 0.048 m3/mg.
基金supported by the National Natural Science Foundation of China(20871042)Natural Science Foundation of the Henan Province(0424270073)
文摘A series of pure and Y3＋-doped TiO2 nanoparticles with high photocatalytic activities were prepared by a sol-gel method using tetra-n-butyl titanate as precursor.The as-prepared catalysts were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and diffuse reflectance spectroscopy（DRS）.The results indicated that yttrium doping could effectively reduce the crystalline size,inhibit the anatase-to-rutile phase transformation and surppress the recombination of the photogenerated electron-hole pairs.The DRS results showed that the optical absorption edge shifted to red direction owing to yttrium ion doping.The photocatalytic activities of samples were evaluated by the photodegradation of methyl orange（MO） aqueous solution under 300 W high pressure mercury lamp irradiation.Photodegradation results revealed that Y3＋ doping could greatly improve the photocatalytic activity of TiO2.In this experiment,the optimal dosage was 1.5 mol.% when samples were calcined at 773 K for 2 h,which caused a MO photodegradation rate of 99.8% under UV irradiation for 70 min.
基金support of the National Natural Science Foundation of China(Grant No.51875155)the Fundamental Research Funds for the Central Universities(Grant No.PA2019GDQT0017).
文摘In the present work,two types of novel nano additives,titanium sulfonate ligand/black phosphorus(TiLi/BP)and titanium dioxide/black phosphorus(TiCVBP)nanocomposites,were prepared.The tribological behavior of the steel/steel friction pairs lubricated by polyalphaolefins type 6(PA06)containing the nanocomposites under boundary lubrication was studied.The worn surfaces were analyzed using modem surface techniques.The experimental results show that the rubbed surfaces became smooth and showed little wear with the addition of the nanocomposites.TiO_(2)/BP nanocomposites can significantly improve the lubricity of BP nanosheets under high contact stress.The synergistic roles of the load-bearing abilities and rolling effect of TiO_(2) nanoparticles,the slip induced by the BP with its layered structure,and the establishment of a tribofilm on the sliding interface are the basis of the tribological mechanisms.
文摘The interest in nano-engineered cements basically brought by the demands on increasing the performance of concrete structures in challenging applications,such as extreme thermal,electrical,and electromagnetic environments.Traditional cementitious materials lack technological capabilities regarding thermal conductivity,electrical resistivity,mechanical strength,and electromagnetic shielding.Such limitations prevent their application in highperformance and multifunctional concrete structures,which are increasingly required in modern construction.The highdimensional complexity of multivariable optimization of multiple properties makes most of the current approaches unsuitable,and so requires new ways to predict,model,and optimize the performance of such advanced materials.In the present contribution,we introduce a holistic approach to the optimization of nano-engineered cements composites incorporating epoxy resin,nano titanium dioxide,carbon nanotubes,and portland cement.Advanced techniques of machine learning used include random forest regressor for multi-output property prediction and eXtreme gradient boosting,an implementation of the gradient-boosting algorithm that proved particularly useful in multi-objective optimization,for electrical codes’thermal and mechanical properties.Bayesian optimization is also employed to decrease the experimental trials and fine-tune the processing parameters;high-dimensional input space is reduced using principal component analysis to attain optimal model performance.Graph neural networks are utilized for modeling structureproperty relations,and Gaussian processes serve as a surrogate model mimicking the outcome of finite element analysis simulation effectively reducing delays at the computational level.The model yields noteworthy improvements:resistivity decreases by 30%–40%,thermal conductivity increases by 25%–30%,and tensile strength increases by 15%–20%.These enhancements make nano-engineered cements composites highly promising for multifunctional applications such as vibration absorption and electromagnetic shielding,which presents the need for smart,high-performance concrete structures for advanced applications in construction.
