There has been an increasing interest <span style="font-family:"">in <span style="font-family:"">research on using bio-renewable polymers as a replacement to traditional synth...There has been an increasing interest <span style="font-family:"">in <span style="font-family:"">research on using bio-renewable polymers as a replacement to traditional synthetic polymers based on petroleum resources for adhesive applications. Cellulose, which is the most abundant biopolymer finds application as a reinforcing agent in conventional adhesives. However, natural polymer cellulose suffers from a few drawbacks like poor water resistance, low mechanical strength, and compatibility within the hydrophobic matrix. For emerging as sustainable alternatives for synthetic polymers, cellulose and its derivatives must have comparable physical, chemical, thermal, and mechanical properties to those of synthetic polymers. To achieve this, cellulose has been chemically modified as it has free hydroxyl groups which act as a site for modification. Among various techniques used crosslinking and silane modification have shown better properties. Various silanes have been identified and used for modifying both micro-cellulose and nano-cellulose, by the formation of covalent bonds. Silanes have the ability to react with the low number of free hydroxyl groups present in the cellulose surfaces, therefore promotes surface modification. Hence referring to the increase in the research works related to the silane modification of cellulose and its applicability focusing on wood adhesives, the main aim of this review paper is to summarize various works relating to this field.展开更多
Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application...Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application range of WPUs.Therefore,solving the problem of water resistance is a way to improve the application range of WPUs.In this study,a series of WPU dispersions were prepared using castor oil as the bio-based polyol.Besides,the thiol-ene photo click reaction was carried out on the WPU films for silane modification.The effect of the silane modification on the chemical structures of the WPU dispersions and the properties of the WPU films was investigated and discussed.The results revealed that the WPU dispersions had a smaller particle size and potential,showing excellent stability.In addition,the modified WPU films showed highly water resistance which 72 h water absorption could be reduced to 1.94%and the contact angle was up to 99.34?.Moreover,the modified WPU films also exhibited excellent solvent resistance(in acid and salt solution)and thermal stability.This study can provide a new way to improve the water-resistance,hydrophobicity,and thermal stability of bio-based waterborne polyurethane for potential application in painting,adhesives and inks.展开更多
The corrosion resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment.In this study,a hierarchical hydroxide zinc carbonate（HZC） film was fabricated on AZ31...The corrosion resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment.In this study,a hierarchical hydroxide zinc carbonate（HZC） film was fabricated on AZ31 magnesium alloy via a simple chemical-bath deposition process using urea aqueous solution.The morphologies,compositions and corrosion resistance of the hydrophobic film were analyzed using scanning electron microscopy,X-ray diffraction and Fourier transform infrared spectrometer,and electrochemical measurements as well.The results revealed that the HZC film displayed flower-like protrusions and had a thickness of approximately 100 um.The fluoroalkylsilane（FAS）-modified HZC film exhibited a hydrophobic property with a water contact angle of 131.3°.The FAS/HZC film significantly improved the corrosion resistance of the AZ31 alloy due to hierarchical structures and hydrophobic modification.展开更多
With the rapid development of flexible wearable electronic products,their application fields and demands are increasing,posing new challenges to flexible conductive materials.This paper selected flexible polydimethyls...With the rapid development of flexible wearable electronic products,their application fields and demands are increasing,posing new challenges to flexible conductive materials.This paper selected flexible polydimethylsiloxane(PDMS)as the substrate.In order to enhance the adhesion between the substrate and the metal coating,dopamine and silanization were used to co-modify its surface.A conductive layer of metallic copper is deposited on its surface using an inexpensive,easy-to-use electroless plating technique.By optimizing the process conditions,it is found that a uniform copper layer of about 0.6μm can be formed on the surface of the substrate by electroless plating at a constant temperature of 45℃ for 30 min with a conductivity of 5556 S/cm.The relative resistance changes under different deformation conditions,and the I-V curve of the LED circuit is not very different.Therefore,this paper prepared a flexible conductor with excellent electrical conductivity,high coating adhesion,and good electrical stability under large-scale deformation.展开更多
Titanium dioxide(TiO_(2))whiskers modified with octadecyltrimethoxysilane were incorporated into the coating solution through a solution blending method.The superhydrophobic coating was designed and fabricated using p...Titanium dioxide(TiO_(2))whiskers modified with octadecyltrimethoxysilane were incorporated into the coating solution through a solution blending method.The superhydrophobic coating was designed and fabricated using polyvinylidene fluoride(PVDF)and polyperfluorinated ethylene propylene(FEP)as the main constituents,while silane-modified TiO_(2) whiskers as the fillers.The results demonstrated that after a 360-h scaling test,the mass of CacO_(3) on the surface of the resulted silane-modified superhydrophobic TiO_(2)-PVDF-FEP coating was only 1.90 mg·cm^(-2),decreased by 37.1%and 16.7%compared with those on the PVDF-FEP coating and the TiO_(2)-PVDF-FEP coating,respectively.The synergistic effects of the air film,silane-modified TiO_(2) whiskers,and superhydrophobicity ensure that this superhydrophobic TiO_(2) PVDF-FEP coating has excellent scale inhibition performance.This study presents a novel approach for advancing the development of superhydrophobic coatings,offering promising prospects for industrial-scale applications in preventive measures.展开更多
文摘There has been an increasing interest <span style="font-family:"">in <span style="font-family:"">research on using bio-renewable polymers as a replacement to traditional synthetic polymers based on petroleum resources for adhesive applications. Cellulose, which is the most abundant biopolymer finds application as a reinforcing agent in conventional adhesives. However, natural polymer cellulose suffers from a few drawbacks like poor water resistance, low mechanical strength, and compatibility within the hydrophobic matrix. For emerging as sustainable alternatives for synthetic polymers, cellulose and its derivatives must have comparable physical, chemical, thermal, and mechanical properties to those of synthetic polymers. To achieve this, cellulose has been chemically modified as it has free hydroxyl groups which act as a site for modification. Among various techniques used crosslinking and silane modification have shown better properties. Various silanes have been identified and used for modifying both micro-cellulose and nano-cellulose, by the formation of covalent bonds. Silanes have the ability to react with the low number of free hydroxyl groups present in the cellulose surfaces, therefore promotes surface modification. Hence referring to the increase in the research works related to the silane modification of cellulose and its applicability focusing on wood adhesives, the main aim of this review paper is to summarize various works relating to this field.
基金This work was sponsored by the National Key Research and Development Program of China(2019YFD1101202,2019YFD1101203)Guangdong Province Science&Technology Program(2018B030306016)+2 种基金Guangdong Provincial Innovation Team for General Key Technologies in Modern Agricultural Industry(2019KJ133)Key Projects of Basic Research and Applied Basic Research of the Higher Education Institutions of Guangdong Province(2018KZDXM014)Guangzhou Municipal Key Laboratory of Woody Biomass Functional New Materials(201905010005).
文摘Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application range of WPUs.Therefore,solving the problem of water resistance is a way to improve the application range of WPUs.In this study,a series of WPU dispersions were prepared using castor oil as the bio-based polyol.Besides,the thiol-ene photo click reaction was carried out on the WPU films for silane modification.The effect of the silane modification on the chemical structures of the WPU dispersions and the properties of the WPU films was investigated and discussed.The results revealed that the WPU dispersions had a smaller particle size and potential,showing excellent stability.In addition,the modified WPU films showed highly water resistance which 72 h water absorption could be reduced to 1.94%and the contact angle was up to 99.34?.Moreover,the modified WPU films also exhibited excellent solvent resistance(in acid and salt solution)and thermal stability.This study can provide a new way to improve the water-resistance,hydrophobicity,and thermal stability of bio-based waterborne polyurethane for potential application in painting,adhesives and inks.
基金supported by the National Natural Science Foundation of China(No.51241001)SDUST Research Fund(No.2014TDJH104)+3 种基金Taishan Scholarship Project of Shandong Province(No.TS20110828)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2013RCJJ006)Scientific Research Foundation of Shandong for Outstanding Young Scientist(No.BS2013CL009)Applied Basic Research Foundation of Qingdao(No.13-1-4-188-jch)
文摘The corrosion resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment.In this study,a hierarchical hydroxide zinc carbonate（HZC） film was fabricated on AZ31 magnesium alloy via a simple chemical-bath deposition process using urea aqueous solution.The morphologies,compositions and corrosion resistance of the hydrophobic film were analyzed using scanning electron microscopy,X-ray diffraction and Fourier transform infrared spectrometer,and electrochemical measurements as well.The results revealed that the HZC film displayed flower-like protrusions and had a thickness of approximately 100 um.The fluoroalkylsilane（FAS）-modified HZC film exhibited a hydrophobic property with a water contact angle of 131.3°.The FAS/HZC film significantly improved the corrosion resistance of the AZ31 alloy due to hierarchical structures and hydrophobic modification.
基金supported by the Natural Science Foundation of Hunan Province(Grant No.2021JJ40463).
文摘With the rapid development of flexible wearable electronic products,their application fields and demands are increasing,posing new challenges to flexible conductive materials.This paper selected flexible polydimethylsiloxane(PDMS)as the substrate.In order to enhance the adhesion between the substrate and the metal coating,dopamine and silanization were used to co-modify its surface.A conductive layer of metallic copper is deposited on its surface using an inexpensive,easy-to-use electroless plating technique.By optimizing the process conditions,it is found that a uniform copper layer of about 0.6μm can be formed on the surface of the substrate by electroless plating at a constant temperature of 45℃ for 30 min with a conductivity of 5556 S/cm.The relative resistance changes under different deformation conditions,and the I-V curve of the LED circuit is not very different.Therefore,this paper prepared a flexible conductor with excellent electrical conductivity,high coating adhesion,and good electrical stability under large-scale deformation.
基金supported by the Natural Science Foundation of Heilongjiang Province(Grant No.LH2022B001)the Science Research Foundation of Daqing Normal University(Grant No.2021ZR02).
文摘Titanium dioxide(TiO_(2))whiskers modified with octadecyltrimethoxysilane were incorporated into the coating solution through a solution blending method.The superhydrophobic coating was designed and fabricated using polyvinylidene fluoride(PVDF)and polyperfluorinated ethylene propylene(FEP)as the main constituents,while silane-modified TiO_(2) whiskers as the fillers.The results demonstrated that after a 360-h scaling test,the mass of CacO_(3) on the surface of the resulted silane-modified superhydrophobic TiO_(2)-PVDF-FEP coating was only 1.90 mg·cm^(-2),decreased by 37.1%and 16.7%compared with those on the PVDF-FEP coating and the TiO_(2)-PVDF-FEP coating,respectively.The synergistic effects of the air film,silane-modified TiO_(2) whiskers,and superhydrophobicity ensure that this superhydrophobic TiO_(2) PVDF-FEP coating has excellent scale inhibition performance.This study presents a novel approach for advancing the development of superhydrophobic coatings,offering promising prospects for industrial-scale applications in preventive measures.
