The enhanced composite nanofibers have attracted great attention for application in recent years. The electrospinning technique was considered to be a prospective production pattern for them. This paper provided a pro...The enhanced composite nanofibers have attracted great attention for application in recent years. The electrospinning technique was considered to be a prospective production pattern for them. This paper provided a promising technique to prepare the polyacrylonitrile （PAN）/halloysite nanotube （HNT） composite nanofbers by using the electrospinning method. The PAN/HNTs composite nanofbers with well enhanced performance were successfully fabricated from a mixture of PAN/DMF/HNTs dispersion solution processed by the electrospinning technique. For achieving good dispersion in PAN polymer, the highly dispersed HNTs were obtained by using polycarboxylate modifcation employing the in-situ spray-drying method. The structure and properties of the composite nanofbers were characterized by TEM, XRD, EDX, IR, and DSC techniques. The obtained PAN/HNTs composite nanofbers with different HNTs contents were about 300-500 nm in diameter. In addition, the mechanical properties of PAN/HNTs composite nanofbers were tested, which exhibited an excellently enhanced performance.展开更多
The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the st...The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the structure and properties of the composite nanofibers by SEM, XRD, FTIR and DSC techniques. The effect of the PMMA/HNTs composite nanofibers in relationship to the mass percentage of HNTs was investigated. The results indicated that HNTs wrapped in polymer matrix were highly oriented and dispersed by the electrospinning technique, resulting in improved thermal stability of the polymer. Moreover, the mechanical properties of the PMMA/HNTs composite nanofibers which were dependent on HNTs mass content were measured, and good enhanced mechanical properties were obtained.展开更多
The polypropylene(PP) nanocomposites filled with pretreated halloysite nanotubes(HNTs) were prepared by the melt-blending method. Before filling, the as-received HNTs powder was at first purified and then modified. Th...The polypropylene(PP) nanocomposites filled with pretreated halloysite nanotubes(HNTs) were prepared by the melt-blending method. Before filling, the as-received HNTs powder was at first purified and then modified. The characterization tests showed that the purified HNTs had less impurity and more uniform pore size distribution and the surface hydrophobicity of the modified HNTs was obviously improved. The mechanical and tribological properties of the PP/HNTs nanocomposites were extensively investigated. The results showed that the tensile, bending and notched impact strength of the PP/HNTs nanocomposites was somewhat improved, but the wear resistance of the PP/HNTs nanocomposites was obviously enhanced.展开更多
Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is ...Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is associated with a highly energy-consuming and heavily polluting process.Solor-driven photocatalytic evolution of H_(2)O_(2) is a promising,eco-friendly,and energy-efficient strategy that holds great potential to substitute the traditional approach.Here,a ternary photocatalyst,NiS/CdS/Halloysite nanotubes(NiS/CdS/HNTs)is designed and prepared with an earth-abundant clay mineral HNTs as the support and NiS as a co-catalyst.The pivotal roles of HNTs and NiS in the photocatalytic process are elucidated by experiments and theoretical calculations.HNTs serve as the carrier,which allows CdS to be uniformly dispersed onto its surface as small particles,increasing effective contact with H_(2)O and O_(2) for H_(2)O_(2) formation.Simultaneously,it resulted in the formation of a Schottky junction between NiS and CdS,which not only favors photogenerated charges separating efficiently but also provides a unidirectional path to transfer electrons.Consequently,the optimized NiS/CdS/HNTs composite demonstrates an H_(2)O_(2) evolution rate of 380.5μmol·g^(-1)·h^(-1) without adding any sacrificial agent or extra O_(2),nearly 5.0 times that of pure CdS.This work suggests a feasible idea for designing and developing highly active and low-cost solar energy catalytic composite materials.展开更多
This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a contr...This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a controlled corrosion degradation of the bioresorbable material.Multifunctional hybrid coatings were obtained on MA8 magnesium alloy.The porous ceramic-like coating synthesized by plasma electrolytic oxidation served as a base for further modification with bioresorbable polymer(polycaprolactone,PCL)contained halloysite nanotubes(HNTs)with corrosion inhibitor(benzotriazole,BTA).The method for HNT impregnating with BTA and introducing them into the matrix of PCL was proposed.The chemical composition of the protective layers was studied using SEM-EDX,XRD,XPS,and Raman microspectroscopy.Anticorrosion protection level of the coated specimens was determined by means of electrochemical techniques,weight loss,and hydrogen evolution tests.The samples with hybrid layers showed the best corrosion protection during 23 h exposure to Hanks’Balanced Salt Solution(|Z|_(f=0.1 Hz)=1.02 MΩ·cm^(2),I_(C)=11 nA·cm^(-2),R_(p)=2.4 MΩ·cm^(2))and the lowest degradation rate(0.021 mm/year)after 7 day of exposure to HBSS among all the tested samples.The electrochemical activity on microscale of samples with the studied coatings was estimated by localized electrochemical techniques.The degradation mechanism of specimens with hybrid layers was proposed.The prospects of hybrid layer application in regulating the resorption process of Mg alloys were shown.展开更多
In this study, the effects of halloysite nanotubes （HNTs） reinforcement in expandable graphite based intumescent fire retardant coatings （IFRCs） developed using a polydimethylsiloxane （PDMS）/phenol BA epoxy syst...In this study, the effects of halloysite nanotubes （HNTs） reinforcement in expandable graphite based intumescent fire retardant coatings （IFRCs） developed using a polydimethylsiloxane （PDMS）/phenol BA epoxy system were investigated. Intumescent coating formulations were developed by incorporating different weight percentages of HNTs and PDMS in basic intumescent ingredients （ammonium polyphosphate/melamine/boric acid/expandable graphite, APP/MEL/BA/EG）. The performance of intumescent formulations was investigated by furnace fire test, Bunsen burner fire test, field emission electron microscopy （FESEM）, thermogravimetric analysis （TGA）, transmission electron microscopy （TEM）, and Fourier transform infrared analysis （FTIR）. The Bunsen burner fire test results indicated that the fire performance of HNTs and PDMS reinforced intumescent formulation has improved due to the development of silicate network over the char residue. Improved expansion in char residue was also noticed in the formulation, SH（3）, due to the minimum decomposition of char carbon. FESEM and TEM results validated the development of silicate network over char layer of coating formulations. A considerable mass loss difference was noticed during thermal gravimetric analysis （TGA） of intumescent coating formulations. Reference formulation, SH（0） with no filler, degraded at 300 ~C and lost 50% of its total mass but SH（3）, due to synergistic effects between PDMS and HNTs, degraded above 400 ~C and showed the maximum thermal stability. XRD analysis showed the development of thermally stable compound mulltie, due to the synergism of HNTs and siloxane during intumescent reactions, which enhanced fire performance. FTIR analysis showed the presence of incorporated siloxane and silicates bonds in char residue, which endorsed the toughness of intumescent char layer produced. Moreover, the synergistic effect ofHNTs, PDMS, and other basic intumescent ingredients enhanced the polymer cross-linking in binder system and improved fire resistive performance of coatings.展开更多
基金supported by the Talent Introduction Fund of Yangzhou University (2012)the Key Research Project-Industry Foresight and General Key Technology of Yangzhou (YZ2015020)+4 种基金the Innovative Talent Program of Green Young Golden Phoenix (yzlyjfjh2015CX073)the Yangzhou Social Development Project (YZ2016072)the Six Talent Peaks of Jiangsu province (2014-XCL-013)the Jiangsu Province Science and Technology Support Project (BE2014613)the Jiangsu Industrial-Academic-Research Prospective Joint Project ( BY2016069-02)
文摘The enhanced composite nanofibers have attracted great attention for application in recent years. The electrospinning technique was considered to be a prospective production pattern for them. This paper provided a promising technique to prepare the polyacrylonitrile （PAN）/halloysite nanotube （HNT） composite nanofbers by using the electrospinning method. The PAN/HNTs composite nanofbers with well enhanced performance were successfully fabricated from a mixture of PAN/DMF/HNTs dispersion solution processed by the electrospinning technique. For achieving good dispersion in PAN polymer, the highly dispersed HNTs were obtained by using polycarboxylate modifcation employing the in-situ spray-drying method. The structure and properties of the composite nanofbers were characterized by TEM, XRD, EDX, IR, and DSC techniques. The obtained PAN/HNTs composite nanofbers with different HNTs contents were about 300-500 nm in diameter. In addition, the mechanical properties of PAN/HNTs composite nanofbers were tested, which exhibited an excellently enhanced performance.
基金supported by the Talent Introduction Fund of Yangzhou University(2012)the Key Research Project-Industry Foresight and General Key Technology of Yangzhou(YZ2015020)+3 种基金the Innovative Talent for the Green Yangzhou Golden Phoenix Program(yzlyjfjh2015CX073)the Jiangsu Province Science and Technology Support Project(BE2014613)the Six Talent Peaks of Jiangsu Province(2014-XCL-013)the Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the structure and properties of the composite nanofibers by SEM, XRD, FTIR and DSC techniques. The effect of the PMMA/HNTs composite nanofibers in relationship to the mass percentage of HNTs was investigated. The results indicated that HNTs wrapped in polymer matrix were highly oriented and dispersed by the electrospinning technique, resulting in improved thermal stability of the polymer. Moreover, the mechanical properties of the PMMA/HNTs composite nanofibers which were dependent on HNTs mass content were measured, and good enhanced mechanical properties were obtained.
基金supported by the Talent Introduction Fund of the Yangzhou University(2012)the Zhejiang High Technology Research Institute of Yangzhou University(2017)+6 种基金the Key Research Project-Industry Foresight and General Key Technology of Yangzhou(YZ2015020)the Innovative Talent Program of Green Yang Golden Phoenix(yzlyjfjh2015CX073)the Yangzhou Social Development Project(YZ2016072)the Jiangsu Province Six Talent Peaks Project(2014-XCL-013)the Jiangsu Province Science and Technology Support Project(BE2014613)the Jiangsu Industrial-Academic-Research Prospective Joint Project(BY2016069-02)the Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The polypropylene(PP) nanocomposites filled with pretreated halloysite nanotubes(HNTs) were prepared by the melt-blending method. Before filling, the as-received HNTs powder was at first purified and then modified. The characterization tests showed that the purified HNTs had less impurity and more uniform pore size distribution and the surface hydrophobicity of the modified HNTs was obviously improved. The mechanical and tribological properties of the PP/HNTs nanocomposites were extensively investigated. The results showed that the tensile, bending and notched impact strength of the PP/HNTs nanocomposites was somewhat improved, but the wear resistance of the PP/HNTs nanocomposites was obviously enhanced.
文摘Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is associated with a highly energy-consuming and heavily polluting process.Solor-driven photocatalytic evolution of H_(2)O_(2) is a promising,eco-friendly,and energy-efficient strategy that holds great potential to substitute the traditional approach.Here,a ternary photocatalyst,NiS/CdS/Halloysite nanotubes(NiS/CdS/HNTs)is designed and prepared with an earth-abundant clay mineral HNTs as the support and NiS as a co-catalyst.The pivotal roles of HNTs and NiS in the photocatalytic process are elucidated by experiments and theoretical calculations.HNTs serve as the carrier,which allows CdS to be uniformly dispersed onto its surface as small particles,increasing effective contact with H_(2)O and O_(2) for H_(2)O_(2) formation.Simultaneously,it resulted in the formation of a Schottky junction between NiS and CdS,which not only favors photogenerated charges separating efficiently but also provides a unidirectional path to transfer electrons.Consequently,the optimized NiS/CdS/HNTs composite demonstrates an H_(2)O_(2) evolution rate of 380.5μmol·g^(-1)·h^(-1) without adding any sacrificial agent or extra O_(2),nearly 5.0 times that of pure CdS.This work suggests a feasible idea for designing and developing highly active and low-cost solar energy catalytic composite materials.
基金supported by Russian Science Foundation,Russia(project no.24-73-10008,https://rscf.ru/en/project/24-73-10008/)the government assignments from the Ministry of Science and Higher Education of the RF,Russia(project no.FWFN-2024-0001).
文摘This article discusses potential solutions to overcome current limitations for clinical implementation of Mg implants by forming the biocompatible hybrid PEO-based inhibitor-and polymer-containing coatings for a controlled corrosion degradation of the bioresorbable material.Multifunctional hybrid coatings were obtained on MA8 magnesium alloy.The porous ceramic-like coating synthesized by plasma electrolytic oxidation served as a base for further modification with bioresorbable polymer(polycaprolactone,PCL)contained halloysite nanotubes(HNTs)with corrosion inhibitor(benzotriazole,BTA).The method for HNT impregnating with BTA and introducing them into the matrix of PCL was proposed.The chemical composition of the protective layers was studied using SEM-EDX,XRD,XPS,and Raman microspectroscopy.Anticorrosion protection level of the coated specimens was determined by means of electrochemical techniques,weight loss,and hydrogen evolution tests.The samples with hybrid layers showed the best corrosion protection during 23 h exposure to Hanks’Balanced Salt Solution(|Z|_(f=0.1 Hz)=1.02 MΩ·cm^(2),I_(C)=11 nA·cm^(-2),R_(p)=2.4 MΩ·cm^(2))and the lowest degradation rate(0.021 mm/year)after 7 day of exposure to HBSS among all the tested samples.The electrochemical activity on microscale of samples with the studied coatings was estimated by localized electrochemical techniques.The degradation mechanism of specimens with hybrid layers was proposed.The prospects of hybrid layer application in regulating the resorption process of Mg alloys were shown.
基金The authors acknowledge the financial and laboratory support provided by UTP via YUTP research grantMechanical Engineering Department of Universiti Teknologi PETRONAS,Malaysia for this study
文摘In this study, the effects of halloysite nanotubes （HNTs） reinforcement in expandable graphite based intumescent fire retardant coatings （IFRCs） developed using a polydimethylsiloxane （PDMS）/phenol BA epoxy system were investigated. Intumescent coating formulations were developed by incorporating different weight percentages of HNTs and PDMS in basic intumescent ingredients （ammonium polyphosphate/melamine/boric acid/expandable graphite, APP/MEL/BA/EG）. The performance of intumescent formulations was investigated by furnace fire test, Bunsen burner fire test, field emission electron microscopy （FESEM）, thermogravimetric analysis （TGA）, transmission electron microscopy （TEM）, and Fourier transform infrared analysis （FTIR）. The Bunsen burner fire test results indicated that the fire performance of HNTs and PDMS reinforced intumescent formulation has improved due to the development of silicate network over the char residue. Improved expansion in char residue was also noticed in the formulation, SH（3）, due to the minimum decomposition of char carbon. FESEM and TEM results validated the development of silicate network over char layer of coating formulations. A considerable mass loss difference was noticed during thermal gravimetric analysis （TGA） of intumescent coating formulations. Reference formulation, SH（0） with no filler, degraded at 300 ~C and lost 50% of its total mass but SH（3）, due to synergistic effects between PDMS and HNTs, degraded above 400 ~C and showed the maximum thermal stability. XRD analysis showed the development of thermally stable compound mulltie, due to the synergism of HNTs and siloxane during intumescent reactions, which enhanced fire performance. FTIR analysis showed the presence of incorporated siloxane and silicates bonds in char residue, which endorsed the toughness of intumescent char layer produced. Moreover, the synergistic effect ofHNTs, PDMS, and other basic intumescent ingredients enhanced the polymer cross-linking in binder system and improved fire resistive performance of coatings.
