The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawa...The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawater conditions.Initially,synthesized microcapsules are incorporated into the epoxy coating.Then,the self-healing capabilities of the coating are studied under immersion using scanning vibrating electrode technique(SVET),open circuit potential(OCP),electrochemical impedance spectroscopy(EIS)and immersion corrosion test on coated samples with intentionally created artificial defects.The last three tests were conducted in a 3.5%NaCl solution.The adhesion of the coating is also studied by pull-off adhesion test.SVET analyses reveal lower ionic current densities in coated samples containing microcapsules during 24 h of immersion.EIS results demonstrate self-healing at the defect site for up to 12 h of immersion.After this time,the corrosion protection diminishes with prolonged immersion in the saline solution.Despite this,the coating with the microcapsules exhibits decrease in the corrosion process compared to the coating without the microcapsules.These results are consistent and complement the outcomes of the immersion tests conducted over 360 and 1056 h,which indicate that coated samples without microcapsules exhibit double the corroded areas around the scribes compared to coated samples containing the microcapsules.These findings offer a promising outlook for applying this coating on offshore carbon steel structures under immersion aiming for a longer lifetime with less maintenance intervention.展开更多
Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solu...Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.展开更多
To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-l...To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-load rigid porous microcapsules(HLRPMs)through subcritical water etching.By optimizing the subcritical water treatment parameters(OH−concentration:0.031 mol/L,tem-perature:240°C,duration:1.5 h),nanoscale through-holes were generated on hollow glass microspheres(shell thickness≈700 nm).The subsequent gradient pressure infiltration of flaxseed oil enabled a record-high core content of 88.2%.Systematic investigations demonstrated that incorporating 3 wt%HLRPMs into epoxy resin composites preserved excellent dielectric properties(breakdown strength≥30 kV/mm)and enhanced tensile strength by 7.52%.In addressing multimodal damage,the system achieved a 95.5%filling efficiency for mechanical scratches,a 97.0%reduction in frictional damage depth,and a 96.2%recovery of insulation following electrical treeing.This biomimetic microcapsule system concurrently improved self-healing capability and matrix performance,offering a promising strategy for the development of next-generation smart insulating materials.展开更多
A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic ox...A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.展开更多
Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls （4.6 mm × 250 mm, 5μm） column with a mixture of methanol-THF-water ...Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls （4.6 mm × 250 mm, 5μm） column with a mixture of methanol-THF-water （66：30：4, V/V/V） as mobile phase at a flow rate of 1.5 mL·min^-1 and the UV detection wavelength was 472 nm. Results The linear range of lycopene was 3.6-18 μg·mL^-1, r = 0.999 8, the average recovery was from 99.81% to 101.06% with RSD less than 1.83%. The RSD of intra-day and interday precision were less than 3.34%. Conclusion The method is simple, accurate and suitable for the determination of lycopene in microcapsules.展开更多
Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then ...Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.展开更多
The nanostructured copper/microcapsule containing liquid core materials composite（copper/liquid microcapsules composite） was prepared using direct current（DC） electrodeposition method.The surface morphology and mi...The nanostructured copper/microcapsule containing liquid core materials composite（copper/liquid microcapsules composite） was prepared using direct current（DC） electrodeposition method.The surface morphology and microstructure of composite were investigated by means of scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and X-ray diffraction（XRD）.The results show that the microstructure of electrodeposited layer transformed from bulk crystal to nano structure because of the participation of microcapsules.The diameters of microcapsules and the copper grain sizes in the composite were 2？20 μm and 10？20 nm,respectively.In addition,the electrodeposition mechanism of composite in the deposition process followed electrochemistry theory,which was proved by the theoretical analysis result and the experiment results.Meanwhile,the co-deposition process model was presented.展开更多
Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation rea...Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation reaction. The products were characterized by means of Fourier transform infrared spectrometry, ^13C NMR spectrometry and ^31p NMR spectrometry. The morphology, the particle size and the particle size distribution, and the thermal properties were also evaluated. The prepared microcapsules exhibit clear and smooth surfaces and have a mean diameter of 28. 13 μm. These microcapsules also have a good thermal stability for long-term use, and have potential applications in minimizing the toxicity of chlorpyrifos through controlled release.展开更多
Fabrication of biocompatible core-shell microcapsules in a controllable and scalable manner remains an important but challenging task.Here,we develop a one-step microfluidic approach for the highthroughput production ...Fabrication of biocompatible core-shell microcapsules in a controllable and scalable manner remains an important but challenging task.Here,we develop a one-step microfluidic approach for the highthroughput production of biocompatible microcapsules,which utilizes single emulsions as templates and controls the precipitation of biocompatible polymer at the water/oil interface.The facile method enables the loading of various oils in the core and the enhancement of polymer shell strength by polyelectrolyte coating.The resulting microcapsules have the advantages of controllability,scalability,biocompatibility,high encapsulation efficiency and high loading capacity.The core-shell microcapsules are ideal delivery vehicles for programmable active release and various controlled release mechanisms are demonstrated,including burst release by vigorous shaking,pH-triggered release for targeted intestinal release and sustained release of perfume over a long period of time.The utility of our technique paves the way for practical applications of core-shell microcapsules.展开更多
Microcapsule technology is a kind of technology wrapping the solid or liquid into minute-sized particles within the field of micrometer or millimeter with film forming materials. This thesis introduces microcapsule te...Microcapsule technology is a kind of technology wrapping the solid or liquid into minute-sized particles within the field of micrometer or millimeter with film forming materials. This thesis introduces microcapsule technology of phase change materials and its main functions and the structural composition, preparation methods and characterization technology of microcapsule of phase change materials. The microcapsule of phase change materials is small in size and its temperature remains unchanged during the process of heat absorption and heat release. It is of great value in research and application prospect due to these characteristics.展开更多
Since the conventional liquid-liquid extraction method suffered from a series of problems such as inefficiency of one stage extraction, vast device occupation and severe emulsification, we adopted microcapsule （MC） ...Since the conventional liquid-liquid extraction method suffered from a series of problems such as inefficiency of one stage extraction, vast device occupation and severe emulsification, we adopted microcapsule （MC） technique to change the former liq- uid-liquid extraction to liquid-solid extraction. Firstly, the piercing method was performed to prepare the empty polysulfone （PSF） microcapsules, which was easy to implement and control. Secondly, the ultrasonic approach was utilized to prepare the fimctional microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester （EHPNA）. We focused on a key factor of the molar ratio of PSF over 1-Methyl-2-pyrrolidinone （NMP）, attaining a loading ratio as high as 7.21 g-EHPNA/g-PSF. Thirdly, we examined the kinetics and thermodynamics of extraction. Kinetic results demonstrated that equilibrium was reached within two hours, with an extraction rate of Sm3＋=Er3＋〉La3＋ Thermodynamic results showed that the extraction of lanthanides complied wi~ the Langmuir law, with an extraction capacity of 0.25~2.30 mmol/g-microcapsule. Fourthly, stripping experiment indicated that three hours were re- quired to accomplish equilibrium for La3＋ and Sm3＋ while longer hours for Er3＋. Finally, seven extraction-stripping cyclic experiments were performed for three mixed elements, the results of which revealed that Sm3＋ and Er3＋ maintained constantly high extractiori amount whilst La3＋ leveled off at approximately 50%. This proposed polysulfone microcapsule containing EHPNA is suitable to be applied to extraction and concentration of rare earth metals.展开更多
One-component, catalyst-free self-healing coatings with double-shelled polymer microcapsules have drawn considerable attention due to wide applications. In this work, the synthesis parameters of double-shelled polymer...One-component, catalyst-free self-healing coatings with double-shelled polymer microcapsules have drawn considerable attention due to wide applications. In this work, the synthesis parameters of double-shelled polymer microcapsules and the mechanism of the self-healing process were systematically investigated. Apart from the chemical structure of the microcapsule shell, the shell thickness, the microcapsule size,and the core fraction could affect the self-healing anticorrosion properties. The synthesis parameters were further optimized in terms of the agitation rate, p H, weight ratio of core to shell, and temperature. Under these conditions, the microcapsule shell consisting of a rough surface formed by poly(urea-formaldehyde) and a smooth inner wall by polyurethane was prepared. The size of the microcapsules and core fraction were calculated to be approximately 30 μm and 75%, respectively. The self-healing anticorrosion coating incorporating as-synthesized microcapsules exhibited corrosion resistance in artificially scratched areas, which was further characterized by electrochemical impedance spectroscopy.展开更多
To study the influences of phase change material(PCM)microcapsules in clothing on human thermal responses,a mathematical model is developed.The improved Stolwijk’s model is used to simulate human thermo-regulatory pr...To study the influences of phase change material(PCM)microcapsules in clothing on human thermal responses,a mathematical model is developed.The improved Stolwijk’s model is used to simulate human thermo-regulatory process,and the coupled heat and moisture transfer including the moisture sorption/desorption of fibers and effects of phase transition temperature range on the phase change processes of the PCM is considered in clothing model.Meanwhile,the theoretical predictions are validated by experimental data.Then,the interactions between human body thermal responses and the heat and moisture transfer in clothing are discussed by comparing the prediction results with PCMs and without PCMs.Also the effects of fiber hygroscopicity on clothing and human thermal responses are compared.The conclusion shows that the clothing with PCMs microcapsules can delay the human temperature variations and decrease the sweat accumulation rate on the skin surface and heat loss during changing of ambient conditions,and fiber hygroscopicity reduces the effect of PCM microcapsules on delaying garment temperature variations very significantly.展开更多
This paper gives a brief report of the preparation of hexadecane microcapsule with polyurea-melamine formaldehyde resin shell materials(HMPM).The sealing performance and thermal stability of HMPM was enhanced much mor...This paper gives a brief report of the preparation of hexadecane microcapsule with polyurea-melamine formaldehyde resin shell materials(HMPM).The sealing performance and thermal stability of HMPM was enhanced much more effectively than that of microcapsule with polyurea shell material(HPM).The results of microscopical imaging analysis system,DSC,TG,and laser particle analyzer were briefly introduced.展开更多
Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as...Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as immobilization carriers by emulsifi cation-internal gelation and complexation reaction,and their contribution on facilitating the growth and metabolism of yeast cells were testifi ed successfully in culture medium-solvent biphasic systems.The cell growth in AC microcapsules is superior to that in alginate beads,and the cells in both immobilization carriers maintain much higher activity than free cells,which demonstrates AC microcapsules can confer yeast cells the ability to resist the adverse effect of solvent.Moreover,the performance of AC microcapsules in biphasic systems could be improved by adjusting the formation of outer polyelectrolyte complex(PEC)membrane to promote the cell growth and metabolic ability under the balance of resisting solvent toxicity and permitting substrate diffusion.Therefore,these findings are quite valuable for applying AC microcapsules as novel immobilization carriers to realize the biotransformation of value-added products in aqueous-solvent biphasic systems.展开更多
A general and versatile strategy to prepare melamine-formaldehyde(MF)microcapsules encapsulating oil-based fragrances by combining solvent evaporation and in situ polymerization was proposed in this work.The oil-based...A general and versatile strategy to prepare melamine-formaldehyde(MF)microcapsules encapsulating oil-based fragrances by combining solvent evaporation and in situ polymerization was proposed in this work.The oil-based fragrance was pre-encapsulated by an inner polyacrylate membrane via solvent evaporation,followed by in situ polymerization of MF precondensates as an outer shell.The polyacrylate membrane is used as an intermediate bridging layer to stabilize the oil-based fragrance,and to provide driving forces for in situ polymerization of MF precondensates through electrostatic attractions between carboxyl groups and ammonium ions.It was demonstrated that MF microcapsules containing clove oil were prepared successfully.The amount and the composition of the intermediate polyacrylate bridging layer were critical.Smooth and sphere-shaped MF-clove oil microcapsules were prepared when the weight ratio of polyacrylate to clove oil was over 60 wt%and the concentration of acrylic acid(AA)increased to 10 wt%in polyacrylate.In addition,MF microcapsules containing sunflower oil and hexyl salicylate were prepared by using this method.The work suggests that this new approach can be potentially used to encapsulate various core materials,tuning the shell properties of microcapsules such as thickness,mechanical strength and release properties.展开更多
Microcapsules containing core materials are promising component for developing self-healing coatings.In the present work,urea-formaldehyde capsule containing core material with size of micrometer was prepared by in-si...Microcapsules containing core materials are promising component for developing self-healing coatings.In the present work,urea-formaldehyde capsule containing core material with size of micrometer was prepared by in-situ encapsulation method.The morphology of the microcapsules was characterized by scanning electron microscopy.A corrosion inhibitor,benzotriazole,was successfully loaded on the outside of microcapsules by layer-by-layer assembling using polyelectrolytes.Thus,the modified microcapsules are promising to provide healing ability combined by release of interior core material and exterior corrosion inhibitor.展开更多
The urea-formaldehyde（UF） capsules filled with a healing agent, a mixture of epoxy resins（epoxy 711 and E-51） as core material, were produced by means of one step in-situ polymerization. The characteristics of the...The urea-formaldehyde（UF） capsules filled with a healing agent, a mixture of epoxy resins（epoxy 711 and E-51） as core material, were produced by means of one step in-situ polymerization. The characteristics of these microcapsules were studied via scanning electron microscopy（SEM）, particle size analysis, FTIR and DSC/TGA. The results show that the dispersed and integrated microcapsules of 5 μm in shell thickness were synthesized successfully. The capsules were produced with diameters ranging from 10 to 250 μm via controlling agitation rate. Young＇s modulus of the capsule was a little lower than those of the epoxy resins, but the microcapsules having such a shell thickness were robust enough to survive handling during manufacturing self-healing composites. When damage occurred in the epoxy matrix, the crack could rupture the microcapsule to make the repairing agent release.展开更多
In this work,a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry(MS) detector was described.We constructed a three-dimensional tumor-endothelial co-culture model for simulating ...In this work,a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry(MS) detector was described.We constructed a three-dimensional tumor-endothelial co-culture model for simulating drug resistance during tumor treatment.On this specially designed integrated platform,the first step was to prepare heterogeneous cell-encapsulated alginate microcapsules for threedimensional co-culture,and the second step was to achieve on-line perfusion culture and continuous drug stimulation on chip.It facilitates cell proliferation analysis and the collection of metabolism medium.After micro solid phase extraction column(SPE) pretreatment,subsequent mass spectrometry could detect drug metabolism.The high activity of two kinds of cells(A549 and HUVEC) shows the biocompatibility of the platform.Paclitaxel was used as a model drug,the distinctions of drug absorption between the mono-culture group and co-culture group were clearly observed by electrospray ionization quadrupole time-of-flight mass spectrometry(ESI-Q-TOF MS).Therefore,the integrated platform has shown promise as a high throughput,low cost for cell metabolism research and drug screening processes.展开更多
For the purpose of overcoming the lack of durability problems associated with superhydrophobic surfaces which hitherto has limited their use;we prepared multi-stimuli wettability response coatings using a mixture of f...For the purpose of overcoming the lack of durability problems associated with superhydrophobic surfaces which hitherto has limited their use;we prepared multi-stimuli wettability response coatings using a mixture of fluorocarbon resin and urea-formaldehyde microcapsules filled with fluorosilane via interfacial polymerization process.The microcapsules are of good thermal stability and can be triggered to release their core content on exposure to atmospheric conditions resulting in the increase in the water contact angle from 97°to 151°.The prepared coatings gave good adhesion strength,and also showed an increase in the hydrophobic property after undergoing scratch,solvent and UV accelerated aging test.In addition,they offered good self-healing of the hydrophobic property after an initial loss due to alkaline immersion and oxygen plasma etching.The electrochemical measurements revealed a remarkable impedance recovery and suppression of corrosion activities,suggesting them to be a potential candidate material for corrosion protection.展开更多
基金supported by CAPES scholarship-Brazil Coordination for the Improvement of Higher Education Personnel(No.88887.507764/2020-00)]by CNPq-Brazil National Council of Technological and Scientific Development(No.308564/2023-5).
文摘The self-healing properties of dual-component epoxy microcapsules are evaluated when incorporated into an epoxy coating.The performance of the coating was assessed under immersion in a saline solution,simulating seawater conditions.Initially,synthesized microcapsules are incorporated into the epoxy coating.Then,the self-healing capabilities of the coating are studied under immersion using scanning vibrating electrode technique(SVET),open circuit potential(OCP),electrochemical impedance spectroscopy(EIS)and immersion corrosion test on coated samples with intentionally created artificial defects.The last three tests were conducted in a 3.5%NaCl solution.The adhesion of the coating is also studied by pull-off adhesion test.SVET analyses reveal lower ionic current densities in coated samples containing microcapsules during 24 h of immersion.EIS results demonstrate self-healing at the defect site for up to 12 h of immersion.After this time,the corrosion protection diminishes with prolonged immersion in the saline solution.Despite this,the coating with the microcapsules exhibits decrease in the corrosion process compared to the coating without the microcapsules.These results are consistent and complement the outcomes of the immersion tests conducted over 360 and 1056 h,which indicate that coated samples without microcapsules exhibit double the corroded areas around the scribes compared to coated samples containing the microcapsules.These findings offer a promising outlook for applying this coating on offshore carbon steel structures under immersion aiming for a longer lifetime with less maintenance intervention.
基金supported by the Jilin Provincial Science and Technology Development Plan Project(No.20220508003RC)the National Natural Science Foundation of China(52202440,52003012)。
文摘Lithium-ion batteries(LIBs)play a critical role in reducing carbon emissions in the automotive industry.However,they face challenges related to safety and performance failures.Smart technologies offer a promising solution to address these issues.Bioinspired microcapsules are a common approach to enhancing the performance and safety of smart LIBs.However,despite their potential,this area has not been thoroughly explored.This review provides an overview of the preparation methods for microcapsules,including physical,chemical,and physicochemical techniques.These microcapsules are categorized based on their mechanisms into electrode self-healing burst microcapsules,interphase-forming sustained-release microcapsules,live-lithium sustained-release microcapsules,and flame-retardant burst microcapsules.A comprehensive analysis of their bioinspired design concepts,mechanisms,and performance is presented,along with the design criteria for microcapsules suitable for LIBs.Finally,the review explores the potential applications of microcapsule technologies in LIBs and their future trends,such as enhancing existing technologies for novel applications like solid-state batteries and developing new types of microcapsules.This review aims to provide a foundation for the implementation of microcapsule technologies in LIBs and to highlight the latest advancements in smart batteries.
基金supported by the National Natural Science Foundation of China(Nos.52377133 and 52077014)the Youth Talent Support Program of Chongqing(CQYC2021058945)the General Program of the Natural Science Foundation of Chongqing Municipality(CSTB2022NSCQ-MSX0444).
文摘To address the inherent trade-off between mechanical strength and repair efficiency in conventional microcapsule-based self-healing technologies,this study presents an eggshell-inspired approach for fabricating high-load rigid porous microcapsules(HLRPMs)through subcritical water etching.By optimizing the subcritical water treatment parameters(OH−concentration:0.031 mol/L,tem-perature:240°C,duration:1.5 h),nanoscale through-holes were generated on hollow glass microspheres(shell thickness≈700 nm).The subsequent gradient pressure infiltration of flaxseed oil enabled a record-high core content of 88.2%.Systematic investigations demonstrated that incorporating 3 wt%HLRPMs into epoxy resin composites preserved excellent dielectric properties(breakdown strength≥30 kV/mm)and enhanced tensile strength by 7.52%.In addressing multimodal damage,the system achieved a 95.5%filling efficiency for mechanical scratches,a 97.0%reduction in frictional damage depth,and a 96.2%recovery of insulation following electrical treeing.This biomimetic microcapsule system concurrently improved self-healing capability and matrix performance,offering a promising strategy for the development of next-generation smart insulating materials.
基金Funded by the National Natural Science Foundation of China(No.52271066)Basic Research and Innovation Project for Vehicle Power+1 种基金Key Project of"Two-Chain Integration"in Shaanxi Province(No.2023-LL-QY-33-3)Xi'an Key Laboratory of Corrosion Protection and Functional Coating Technology for Military and Civil Light Alloy and Key Project of Shaanxi Natural Science Foundation Research Program(No.2021JZ-54)。
文摘A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.
基金Special Research Foundation of Ph.D. Study in University(20040291004)Major Project of Chinese(National Programs for Fundamental Research(2003CB716000)
文摘Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls （4.6 mm × 250 mm, 5μm） column with a mixture of methanol-THF-water （66：30：4, V/V/V） as mobile phase at a flow rate of 1.5 mL·min^-1 and the UV detection wavelength was 472 nm. Results The linear range of lycopene was 3.6-18 μg·mL^-1, r = 0.999 8, the average recovery was from 99.81% to 101.06% with RSD less than 1.83%. The RSD of intra-day and interday precision were less than 3.34%. Conclusion The method is simple, accurate and suitable for the determination of lycopene in microcapsules.
文摘Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.
基金Project(50771010) supported by the National Natural Science Foundation of China
文摘The nanostructured copper/microcapsule containing liquid core materials composite（copper/liquid microcapsules composite） was prepared using direct current（DC） electrodeposition method.The surface morphology and microstructure of composite were investigated by means of scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and X-ray diffraction（XRD）.The results show that the microstructure of electrodeposited layer transformed from bulk crystal to nano structure because of the participation of microcapsules.The diameters of microcapsules and the copper grain sizes in the composite were 2？20 μm and 10？20 nm,respectively.In addition,the electrodeposition mechanism of composite in the deposition process followed electrochemistry theory,which was proved by the theoretical analysis result and the experiment results.Meanwhile,the co-deposition process model was presented.
文摘Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation reaction. The products were characterized by means of Fourier transform infrared spectrometry, ^13C NMR spectrometry and ^31p NMR spectrometry. The morphology, the particle size and the particle size distribution, and the thermal properties were also evaluated. The prepared microcapsules exhibit clear and smooth surfaces and have a mean diameter of 28. 13 μm. These microcapsules also have a good thermal stability for long-term use, and have potential applications in minimizing the toxicity of chlorpyrifos through controlled release.
基金supported by the National Natural Science Foundation of China (Nos.21878258 and 11704331)"theFundamental Research Funds for the Central Universities" (No. 2018QNA4046)+2 种基金the Youth Funds of the State Key Laboratory of Fluid Power and Mechatronic Systems (Zhejiang University)supported by the National Science Foundation (No. DMR-1310266)the Harvard Materials Research Science and Engineering Center (No.DMR-1420570)
文摘Fabrication of biocompatible core-shell microcapsules in a controllable and scalable manner remains an important but challenging task.Here,we develop a one-step microfluidic approach for the highthroughput production of biocompatible microcapsules,which utilizes single emulsions as templates and controls the precipitation of biocompatible polymer at the water/oil interface.The facile method enables the loading of various oils in the core and the enhancement of polymer shell strength by polyelectrolyte coating.The resulting microcapsules have the advantages of controllability,scalability,biocompatibility,high encapsulation efficiency and high loading capacity.The core-shell microcapsules are ideal delivery vehicles for programmable active release and various controlled release mechanisms are demonstrated,including burst release by vigorous shaking,pH-triggered release for targeted intestinal release and sustained release of perfume over a long period of time.The utility of our technique paves the way for practical applications of core-shell microcapsules.
文摘Microcapsule technology is a kind of technology wrapping the solid or liquid into minute-sized particles within the field of micrometer or millimeter with film forming materials. This thesis introduces microcapsule technology of phase change materials and its main functions and the structural composition, preparation methods and characterization technology of microcapsule of phase change materials. The microcapsule of phase change materials is small in size and its temperature remains unchanged during the process of heat absorption and heat release. It is of great value in research and application prospect due to these characteristics.
基金supported by the National Key Basic Research Program of China(2012CBA01203)the Specialized Research Fund for Doctoral Program of Higher Education of Ministry of Education of China(20130002110018)
文摘Since the conventional liquid-liquid extraction method suffered from a series of problems such as inefficiency of one stage extraction, vast device occupation and severe emulsification, we adopted microcapsule （MC） technique to change the former liq- uid-liquid extraction to liquid-solid extraction. Firstly, the piercing method was performed to prepare the empty polysulfone （PSF） microcapsules, which was easy to implement and control. Secondly, the ultrasonic approach was utilized to prepare the fimctional microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester （EHPNA）. We focused on a key factor of the molar ratio of PSF over 1-Methyl-2-pyrrolidinone （NMP）, attaining a loading ratio as high as 7.21 g-EHPNA/g-PSF. Thirdly, we examined the kinetics and thermodynamics of extraction. Kinetic results demonstrated that equilibrium was reached within two hours, with an extraction rate of Sm3＋=Er3＋〉La3＋ Thermodynamic results showed that the extraction of lanthanides complied wi~ the Langmuir law, with an extraction capacity of 0.25~2.30 mmol/g-microcapsule. Fourthly, stripping experiment indicated that three hours were re- quired to accomplish equilibrium for La3＋ and Sm3＋ while longer hours for Er3＋. Finally, seven extraction-stripping cyclic experiments were performed for three mixed elements, the results of which revealed that Sm3＋ and Er3＋ maintained constantly high extractiori amount whilst La3＋ leveled off at approximately 50%. This proposed polysulfone microcapsule containing EHPNA is suitable to be applied to extraction and concentration of rare earth metals.
基金financially supported by the National Key Research and Development Plan (No. 2016YFC0303700)the National Natural Science Foundation of China (No. 51803215)+1 种基金CAS Pioneer Hundred Talents ProgramBeijing Municipal Natural Science Foundation (No. 2182075)
文摘One-component, catalyst-free self-healing coatings with double-shelled polymer microcapsules have drawn considerable attention due to wide applications. In this work, the synthesis parameters of double-shelled polymer microcapsules and the mechanism of the self-healing process were systematically investigated. Apart from the chemical structure of the microcapsule shell, the shell thickness, the microcapsule size,and the core fraction could affect the self-healing anticorrosion properties. The synthesis parameters were further optimized in terms of the agitation rate, p H, weight ratio of core to shell, and temperature. Under these conditions, the microcapsule shell consisting of a rough surface formed by poly(urea-formaldehyde) and a smooth inner wall by polyurethane was prepared. The size of the microcapsules and core fraction were calculated to be approximately 30 μm and 75%, respectively. The self-healing anticorrosion coating incorporating as-synthesized microcapsules exhibited corrosion resistance in artificially scratched areas, which was further characterized by electrochemical impedance spectroscopy.
基金supported by the National Natural Science Foundation of China (No. 50706017)the Research Funds of Nanjing University of Aeronautics and Astronautics (No.NS2010009)
文摘To study the influences of phase change material(PCM)microcapsules in clothing on human thermal responses,a mathematical model is developed.The improved Stolwijk’s model is used to simulate human thermo-regulatory process,and the coupled heat and moisture transfer including the moisture sorption/desorption of fibers and effects of phase transition temperature range on the phase change processes of the PCM is considered in clothing model.Meanwhile,the theoretical predictions are validated by experimental data.Then,the interactions between human body thermal responses and the heat and moisture transfer in clothing are discussed by comparing the prediction results with PCMs and without PCMs.Also the effects of fiber hygroscopicity on clothing and human thermal responses are compared.The conclusion shows that the clothing with PCMs microcapsules can delay the human temperature variations and decrease the sweat accumulation rate on the skin surface and heat loss during changing of ambient conditions,and fiber hygroscopicity reduces the effect of PCM microcapsules on delaying garment temperature variations very significantly.
基金the financial support from the National Basic Research Program of China(No. 2009CB623200)the National Natural Science Foundation of China(No.50539040)the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ 0725).
文摘This paper gives a brief report of the preparation of hexadecane microcapsule with polyurea-melamine formaldehyde resin shell materials(HMPM).The sealing performance and thermal stability of HMPM was enhanced much more effectively than that of microcapsule with polyurea shell material(HPM).The results of microscopical imaging analysis system,DSC,TG,and laser particle analyzer were briefly introduced.
基金Supported by the National Natural Science Foundation of China(No.21276033)the Open Foundation of the State Key Laboratory of Bioactive Seaweed Substances(Nos.SKL-BASS1707,SKL-BASS1711)the Liaoning Provincial BaiQianWan Talents Program(No.2017-6)
文摘Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as immobilization carriers by emulsifi cation-internal gelation and complexation reaction,and their contribution on facilitating the growth and metabolism of yeast cells were testifi ed successfully in culture medium-solvent biphasic systems.The cell growth in AC microcapsules is superior to that in alginate beads,and the cells in both immobilization carriers maintain much higher activity than free cells,which demonstrates AC microcapsules can confer yeast cells the ability to resist the adverse effect of solvent.Moreover,the performance of AC microcapsules in biphasic systems could be improved by adjusting the formation of outer polyelectrolyte complex(PEC)membrane to promote the cell growth and metabolic ability under the balance of resisting solvent toxicity and permitting substrate diffusion.Therefore,these findings are quite valuable for applying AC microcapsules as novel immobilization carriers to realize the biotransformation of value-added products in aqueous-solvent biphasic systems.
基金Supported by the National Natural Science Foundation of China(21466016,21577053)the Natural Science Foundation of Yunnan Province(2016FB024).
文摘A general and versatile strategy to prepare melamine-formaldehyde(MF)microcapsules encapsulating oil-based fragrances by combining solvent evaporation and in situ polymerization was proposed in this work.The oil-based fragrance was pre-encapsulated by an inner polyacrylate membrane via solvent evaporation,followed by in situ polymerization of MF precondensates as an outer shell.The polyacrylate membrane is used as an intermediate bridging layer to stabilize the oil-based fragrance,and to provide driving forces for in situ polymerization of MF precondensates through electrostatic attractions between carboxyl groups and ammonium ions.It was demonstrated that MF microcapsules containing clove oil were prepared successfully.The amount and the composition of the intermediate polyacrylate bridging layer were critical.Smooth and sphere-shaped MF-clove oil microcapsules were prepared when the weight ratio of polyacrylate to clove oil was over 60 wt%and the concentration of acrylic acid(AA)increased to 10 wt%in polyacrylate.In addition,MF microcapsules containing sunflower oil and hexyl salicylate were prepared by using this method.The work suggests that this new approach can be potentially used to encapsulate various core materials,tuning the shell properties of microcapsules such as thickness,mechanical strength and release properties.
基金financially supported by the National Natural Science Foundation of China(Grant No.51001109)
文摘Microcapsules containing core materials are promising component for developing self-healing coatings.In the present work,urea-formaldehyde capsule containing core material with size of micrometer was prepared by in-situ encapsulation method.The morphology of the microcapsules was characterized by scanning electron microscopy.A corrosion inhibitor,benzotriazole,was successfully loaded on the outside of microcapsules by layer-by-layer assembling using polyelectrolytes.Thus,the modified microcapsules are promising to provide healing ability combined by release of interior core material and exterior corrosion inhibitor.
基金Supported by the National Natural Science Foundation of China(Nos.50775222 and 50735006)
文摘The urea-formaldehyde（UF） capsules filled with a healing agent, a mixture of epoxy resins（epoxy 711 and E-51） as core material, were produced by means of one step in-situ polymerization. The characteristics of these microcapsules were studied via scanning electron microscopy（SEM）, particle size analysis, FTIR and DSC/TGA. The results show that the dispersed and integrated microcapsules of 5 μm in shell thickness were synthesized successfully. The capsules were produced with diameters ranging from 10 to 250 μm via controlling agitation rate. Young＇s modulus of the capsule was a little lower than those of the epoxy resins, but the microcapsules having such a shell thickness were robust enough to survive handling during manufacturing self-healing composites. When damage occurred in the epoxy matrix, the crack could rupture the microcapsule to make the repairing agent release.
基金supported by the National Natural Science Foundation of China(Nos.21727814,21435002 and 21621003)。
文摘In this work,a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry(MS) detector was described.We constructed a three-dimensional tumor-endothelial co-culture model for simulating drug resistance during tumor treatment.On this specially designed integrated platform,the first step was to prepare heterogeneous cell-encapsulated alginate microcapsules for threedimensional co-culture,and the second step was to achieve on-line perfusion culture and continuous drug stimulation on chip.It facilitates cell proliferation analysis and the collection of metabolism medium.After micro solid phase extraction column(SPE) pretreatment,subsequent mass spectrometry could detect drug metabolism.The high activity of two kinds of cells(A549 and HUVEC) shows the biocompatibility of the platform.Paclitaxel was used as a model drug,the distinctions of drug absorption between the mono-culture group and co-culture group were clearly observed by electrospray ionization quadrupole time-of-flight mass spectrometry(ESI-Q-TOF MS).Therefore,the integrated platform has shown promise as a high throughput,low cost for cell metabolism research and drug screening processes.
基金financial support from the Shenyang Science and Technology Plan Project(Y17-1-039)。
文摘For the purpose of overcoming the lack of durability problems associated with superhydrophobic surfaces which hitherto has limited their use;we prepared multi-stimuli wettability response coatings using a mixture of fluorocarbon resin and urea-formaldehyde microcapsules filled with fluorosilane via interfacial polymerization process.The microcapsules are of good thermal stability and can be triggered to release their core content on exposure to atmospheric conditions resulting in the increase in the water contact angle from 97°to 151°.The prepared coatings gave good adhesion strength,and also showed an increase in the hydrophobic property after undergoing scratch,solvent and UV accelerated aging test.In addition,they offered good self-healing of the hydrophobic property after an initial loss due to alkaline immersion and oxygen plasma etching.The electrochemical measurements revealed a remarkable impedance recovery and suppression of corrosion activities,suggesting them to be a potential candidate material for corrosion protection.
