The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hi...The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hinders the understanding of the interaction mechanism between surfactant groups and oxygen-containing functional groups at the surface of low-rank coal.In this study,we investigate the flotation of low-rank coal in the presence of a composite collector by using a combined theoretical and experimental approach.The maximum flotation mass recovery achieved was 82.89%using a 3:1 mixture of dodecane and castor oil acid.Fourier-transform infrared and X-ray photoelectron spectroscopic analyses showed that castor oil acid was effectively adsorbed onto the surface of low-rank coal,enhancing the hydrophobicity of the coal.In addition,the diffusion coefficient of water molecules in the water-composite collector-coal system was greater than that in the dodecane system.Moreover,due to the presence of castor oil acid in the flotation process,the adsorption distance of dodecane and low-rank coal became shorter.Molecular dynamics simulations revealed that the diffusion and interaction of surfactant molecules at the interface of low-rank coal particles and water was enhanced because the adsorption of the dodecane-castor oil acid mixture is primarily controlled by hydrogen bonds and electrostatic attraction.Based on these results,a better surfactant for flotation of low-rank coal is also proposed.展开更多
It is of great significance to synthesize carbon dots(CDs)with desirable hydrophilicity for the ever-growing application of CDs in different fields.In this study,the hydrophilic and hydrophobic CDs were facilely prepa...It is of great significance to synthesize carbon dots(CDs)with desirable hydrophilicity for the ever-growing application of CDs in different fields.In this study,the hydrophilic and hydrophobic CDs were facilely prepared by solvothermal treatment of o-dihydroxybenzene and urea in N,N-dimethylformamide(DMF).Optimization experiments revealed that the solvothermal temperature has a great impact on the surface states of the CDs.The hydrophobic CDs with a contact angle of 110.7°was obtained at 200℃.The structural and optical characterizations,along with theoretical calculations elucidated that the lipophilic nature of the CDs was resulting from the formation of polymer chains.The presence of extended conjugated sp^(2)-domains and amino groups contributed to the red emission of the CDs synthesized at low reaction temperatures(160-200℃).With the further increase of solvothermal temperature,the hydrophobic CDs were gradually transformed to the hydrophilic state accompanying the blue shift of the fluorescence of the CDs.The highly hydrophilic CDs with a contact angle of 25.9°were obtained at 240℃ due to the increased formation of hydrophilic functional groups on the surface of CDs.The red emissive CDs exhibited a sensitive color and fluorescence response to ethanol content while the fluorescence of the blue emissive CDs remained constant.By combining the two kinds of CDs,a dual-emission sensor was constructed,which was successfully applied for the evaluation of the alcoholic strength in commercial Baijiu commodities in both fluorometric and colorimetric modes.展开更多
Metallic materials, such as Ti, Zr, Nb, Ta, and their alloys, and also stainless steels are widely attractive as osteoconductive materials in the dental and orthopedic fields. Ceramics and polymers are also commonly u...Metallic materials, such as Ti, Zr, Nb, Ta, and their alloys, and also stainless steels are widely attractive as osteoconductive materials in the dental and orthopedic fields. Ceramics and polymers are also commonly used as biomaterials. However, they do not have high osteoconductivity in their pure form, and surface coatings with bioactive substances, such as hydroxyapatite or TiO2, are needed before implantation into the bone. Many reports claim that the surface chemical properties of implants, in particular, hydrophilicity and hydrophobicity, strongly affect the biological reactions. However, the effect of surface properties on osteoconductivity is not clear. In this review, we focus on the relationship between the surface hydrophilicity of metallic implants and osteoconductivity using in vivo evaluation, and the control of the osteoconductivity is discussed from the viewpoint of protein adsorption in implants.展开更多
Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxan...Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxane) (PMPS) in the presence of dimethyl carbonate has been studied. Morphology, particle size, surface area and coating microstructure of modified silicas were analyzed by methods of transmission electron and atomic force microscopies, nitrogen adsorption-desorption data. Carbon contents in the grafted modifying layer of organosilicas were determined using IR spectroscopy and elemental analysis. Hydrophilic-hydrophobic properties of surface of the obtained modified silicas were estimated by measurements of contact angles of wetting. It was shown that modification of pyrogenic silicas with mixtures of poly(methylphenylsiloxane) and dimethyl carbonate allows to obtain the homogeneous hydrophobic products and serve their nanodispersity.展开更多
Polydimethylsiloxane(PDMS)is a dominant material in the fabrication of microfluidic devices to generate water-in-oil droplets,particularly lipid-stabilized droplets,because of its highly hydrophobic nature.However,its...Polydimethylsiloxane(PDMS)is a dominant material in the fabrication of microfluidic devices to generate water-in-oil droplets,particularly lipid-stabilized droplets,because of its highly hydrophobic nature.However,its key property of hydrophobicity has hindered its use in the microfluidic generation of oil-in-water droplets,which requires channels to have hydrophilic surface properties.In this article,we developed,optimized,and characterized a method to produce PDMS with a hydrophilic surface via the deposition of polyvinyl alcohol following plasma treatment and demonstrated its suitability for droplet generation.The proposed method is simple,quick,effective,and low cost and is versatile with respect to surfactants,with droplets being successfully generated using both anionic surfactants and more biologically relevant phospholipids.This method also allows the device to be selectively patterned with both hydrophilic and hydrophobic regions,leading to the generation of double emulsions and inverted double emulsions.展开更多
基金the Foundation of Guizhou Province(No.Qiankehe-ZK[2021]Yiban 255)the National Natural Science Foundation of China(No.52264032)the Foundation of Liupanshui Normal University(No.LPSSYLPY202122).
文摘The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hinders the understanding of the interaction mechanism between surfactant groups and oxygen-containing functional groups at the surface of low-rank coal.In this study,we investigate the flotation of low-rank coal in the presence of a composite collector by using a combined theoretical and experimental approach.The maximum flotation mass recovery achieved was 82.89%using a 3:1 mixture of dodecane and castor oil acid.Fourier-transform infrared and X-ray photoelectron spectroscopic analyses showed that castor oil acid was effectively adsorbed onto the surface of low-rank coal,enhancing the hydrophobicity of the coal.In addition,the diffusion coefficient of water molecules in the water-composite collector-coal system was greater than that in the dodecane system.Moreover,due to the presence of castor oil acid in the flotation process,the adsorption distance of dodecane and low-rank coal became shorter.Molecular dynamics simulations revealed that the diffusion and interaction of surfactant molecules at the interface of low-rank coal particles and water was enhanced because the adsorption of the dodecane-castor oil acid mixture is primarily controlled by hydrogen bonds and electrostatic attraction.Based on these results,a better surfactant for flotation of low-rank coal is also proposed.
基金supported by the National Natural Science Foundation of China(Nos.51973083,22376081)the Fundamental Research Funds for the Central Universities(No.JUSRP22027).
文摘It is of great significance to synthesize carbon dots(CDs)with desirable hydrophilicity for the ever-growing application of CDs in different fields.In this study,the hydrophilic and hydrophobic CDs were facilely prepared by solvothermal treatment of o-dihydroxybenzene and urea in N,N-dimethylformamide(DMF).Optimization experiments revealed that the solvothermal temperature has a great impact on the surface states of the CDs.The hydrophobic CDs with a contact angle of 110.7°was obtained at 200℃.The structural and optical characterizations,along with theoretical calculations elucidated that the lipophilic nature of the CDs was resulting from the formation of polymer chains.The presence of extended conjugated sp^(2)-domains and amino groups contributed to the red emission of the CDs synthesized at low reaction temperatures(160-200℃).With the further increase of solvothermal temperature,the hydrophobic CDs were gradually transformed to the hydrophilic state accompanying the blue shift of the fluorescence of the CDs.The highly hydrophilic CDs with a contact angle of 25.9°were obtained at 240℃ due to the increased formation of hydrophilic functional groups on the surface of CDs.The red emissive CDs exhibited a sensitive color and fluorescence response to ethanol content while the fluorescence of the blue emissive CDs remained constant.By combining the two kinds of CDs,a dual-emission sensor was constructed,which was successfully applied for the evaluation of the alcoholic strength in commercial Baijiu commodities in both fluorometric and colorimetric modes.
文摘Metallic materials, such as Ti, Zr, Nb, Ta, and their alloys, and also stainless steels are widely attractive as osteoconductive materials in the dental and orthopedic fields. Ceramics and polymers are also commonly used as biomaterials. However, they do not have high osteoconductivity in their pure form, and surface coatings with bioactive substances, such as hydroxyapatite or TiO2, are needed before implantation into the bone. Many reports claim that the surface chemical properties of implants, in particular, hydrophilicity and hydrophobicity, strongly affect the biological reactions. However, the effect of surface properties on osteoconductivity is not clear. In this review, we focus on the relationship between the surface hydrophilicity of metallic implants and osteoconductivity using in vivo evaluation, and the control of the osteoconductivity is discussed from the viewpoint of protein adsorption in implants.
文摘Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxane) (PMPS) in the presence of dimethyl carbonate has been studied. Morphology, particle size, surface area and coating microstructure of modified silicas were analyzed by methods of transmission electron and atomic force microscopies, nitrogen adsorption-desorption data. Carbon contents in the grafted modifying layer of organosilicas were determined using IR spectroscopy and elemental analysis. Hydrophilic-hydrophobic properties of surface of the obtained modified silicas were estimated by measurements of contact angles of wetting. It was shown that modification of pyrogenic silicas with mixtures of poly(methylphenylsiloxane) and dimethyl carbonate allows to obtain the homogeneous hydrophobic products and serve their nanodispersity.
基金This work was supported by the EPSRC(grants EP/K038648/1 and EP/J017566/1)by an EPSRC Fellowship awarded to YE(grant EP/N016998/1).
文摘Polydimethylsiloxane(PDMS)is a dominant material in the fabrication of microfluidic devices to generate water-in-oil droplets,particularly lipid-stabilized droplets,because of its highly hydrophobic nature.However,its key property of hydrophobicity has hindered its use in the microfluidic generation of oil-in-water droplets,which requires channels to have hydrophilic surface properties.In this article,we developed,optimized,and characterized a method to produce PDMS with a hydrophilic surface via the deposition of polyvinyl alcohol following plasma treatment and demonstrated its suitability for droplet generation.The proposed method is simple,quick,effective,and low cost and is versatile with respect to surfactants,with droplets being successfully generated using both anionic surfactants and more biologically relevant phospholipids.This method also allows the device to be selectively patterned with both hydrophilic and hydrophobic regions,leading to the generation of double emulsions and inverted double emulsions.
