Materials
·
2020
·Vol. 13
·期 2
·326
·
IF 3.057
Yanxuan Ma,Yingrui Zhang,Jiatong Liu,Yi Sun,Yajie Ge,Xiaoning Yan,Jian Wu
Polyurea microcapsules with Ethylenediamine (EDA) as the core material were synthesized. A set of characterization methods, including optical and scanning electron microscopy (OM and SEM), the Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to confirm the microcapsule morphology and chemical structures. The influence of emulsifier content and stirring rate on size and morphology of the microcapsules was investigated, and the self-healing performance of EDA-Polyurea microcapsule/epoxy coatings was evaluated by electrochemical impedance spectroscopy (EIS) measurements. The results showed that the microcapsules obtained had good spherical shape with a mean diameter of 0.54–0.70 μm. Compared with pure core material, the microcapsule showed excellent thermostability, and the content of core materials was up to 56.00 wt%. The epoxy coating with 5.0 wt% EDA-Polyurea microcapsules achieved average corrosion resistance efficiencies of 90.00%, significantly enhancing the capability of the scratched coating to resist external corrosion.Keywords:ethylenediamine;polyurea;microcapsules;self-healing;anti-corrosion
研究领域:
材料科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 42
·
IF 1.866
Yu Zhang,Jia Song,Hongling Chen
The purpose of the present work was to develop a fragrance encapsulation system using polyacrylate/paraffin microcapsules. The Polyacrylate/paraffin microcapsules were fabricated by the method of suspension polymerization in Pickering emulsion. Morphology, size distribution, and thermal resistance of polyacrylate/paraffin microcapsules were investigated by scanning electron microscopy, light scattering particle size analyzer, and thermogravimetric analyzer. Results indicated that the crosslinked PMMA/paraffin microcapsules and P(MMA-co-BMA)/paraffin microcapsules prepared under optimal conditions presented regular spherical shape and similar size distribution. The crosslinked P(MMA-co-BMA)/paraffin microcapsules exhibited better thermal stability, with a thermal resistance temperature up to 184 °C. Fragrance microcapsules were prepared by encapsulating fragrance into crosslinked P(MMA-co-BMA)/paraffin microcapsules. The prolonged release performance of fragrance microcapsules was measured by ultraviolet-visible near-infrared spectrophotometer. 63.9% fragrance was retained after exposing fragrance microcapsules in air for 3 months, and the fragrance continued to release over 96 h in surfactant solution (sodium lauryl sulfonate, 20 wt %). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 44136.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Kaichen Wang,Tianying Zhang,Tieying Wang,Chao Xu,Feng Ye,Zhirong Liao
Metallic phase change materials (PCMs) have the advantages of large phase change latent heat, high heat storage density and broad application prospects in various high temperature industrial waste heat recovery and utilization. However, due to the strong corrosion of molten metal at high temperature, appropriate packaging technology is the prerequisite for the promotion and application of metallic PCMs. In this research, a high temperature PCM microencapsulating technology with SiCN shell and a new microencapsulation method was proposed. The high temperature microencapsulated phase change materials (MEPCMs) with the core–shell mass ratios of 5:1, 4:1 and 3:1 were prepared by “solvent evaporation-heating curing” method, using SiCN cured by organic polysilazane (OPSZ) as heat resistant shell material and Al-Si particles as core PCMs. The mechanisms of shell formation and coating of OPSZ were studied experimentally, as well as the material properties and thermal performance of MEPCMs. With the increase of temperature, OPSZ gradually formed a dense SiCN shell on the surface of Al-Si particles. The experimental results showed that MEPCMs with the core–shell mass ratio of 4:1 had a high phase change temperature (571.9 °C-573.7 °C) and good heat storage capability (281.2 J/g-282.9 J/g). SiCN shell was conducive to maintain a complete core–shell structure, and exhibited excellent thermal resistance and oxidation resistance to protect inner core materials during thermal cycles. Therefore, the prepared microcapsule was a potential heat storage material, which provided a new idea for developing microencapsulation method of high temperature PCMs.
研究领域:
材料科学
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能源工程
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Junqing Qian,Yan Chen,Qian Wang,Xiaohua Zhao,Haiyan Yang,Feng Gong,Hui Guo
Nisin is food preservative with good food safety and is widely used around the world. However, nisin degrades during food processing and storage, seriously affecting its antibacterial function. In order to improve the stability of nisin, nisin microcapsules were prepared by complex embedding nisin with pectin and chitosan. By selecting the mass ratio of pectin to nisin and chitosan, the microcapsules of nisin loading 200 mg with 81.15% encapsulation efficiency were prepared in aqueous solution of pH 4.0. The results of zeta potential of pectin, chitosan, nisin and microcapsules, infrared spectra and X-Ray diffraction spectra confirmed the embedding of nisin by pectin-chitosan. The adsorption isotherm of pectin and chitosan showed that chitosan and pectin mainly adsorbed by monolayer to form microcapsules. Compared with the same amount of free nisin, bactericidal efficiency decreased within 24 h, which showed there is a release process in microcapsules. However, after treated with 121 °C for 10 min, the sterilization activity loss of nisin was significantly lower than that of free nisin, which showed the thermal stability of nisin pectin microcapsules was greatly increased. The nisin microcapsules with good thermal stability and sustained-release effect can be better applied in future.
研究领域:
食品科学
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生物化学
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产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2015
·Vol. 15
·期 1
·600-605
·
IF 1.556
Jiang Ping,Li Duxin,Xiao Ya,Yang Xingxing,Liu Yuejun
The biodegradable microcapsules based on chitosan for a controlled delivery of clove oil were prepared by the single coagulation process. The effect of chitosan concentration, core to shell ratio, types of emulsifier, flocculating agent and hardening agent on the microcapsule diameter
and the particle size distribution of microcapsule were investigated. The optimized conditions for the preparation of microcapsules with well-defined structure and narrow dispersibility were under that (1) the concentration of chitosan was 1.0 wt%, (2) clove oil to chitosan ratio was 75:25,
(3) OP-10 and 10 wt% sodium sulfate were used as emulsifier and flocculating agent respectively, and (4) the concentration hardening agent glyoxal was 1 wt% based on the weight of chitosan. The uniform spherical structures with smooth surfaces with a particle size distribution of 1–15
μm were evidenced by SEM images of microcapsules. Core–shell, hetero-structures were confirmed by optical micrograph. The chemical component of the microcapsules was determined by FTIR. Thermal analysis showed the microcapsules were thermally stable below 150°C. It was
found that the pH value and temperature play important roles on the release rate of clove oil from the microcapsules. The release volume of clove oil from microcapsules at pH = 7, and pH = 10 were smaller than that at pH = 2. And the release volume of Clove oil from microcapsules at 60°C
was smaller than that at 20°C and 40°C, which showed a sustained and prolonged release.
研究领域:
食品科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
Food and Bioprocess Technology
·
2020
·Vol. 13
·期 9
·1621-1632
·
IF 3.356
Wan Jiawei,Pei Yaqiong,Hu Ying,Ai Tingyang,Sheng Feng,Li Jing,Li Bin
Preservation of refrigerated meat has always been a concern in food industry. In our study, eugenol (Eu) microcapsules were prepared to solve this problem. Eu was embedded into a gelatin-based emulgel with both low-energy and high-energy methods. The emulgel was further spray dried to obtain the Eu microcapsule. The physicochemical properties, microstructure, and thermodynamic properties of the microcapsules were studied. Results showed that the microcapsule powders prepared from the high-energy emulgel (HEG) contained less water and appeared no caking. But the microcapsule prepared from the low-energy emulgel (LEG) showed more regular shape. After dissolution, the reconstructed emulgel was investigated in terms of texture, microstructure, thermal properties, and preservation effects. Reconstructed emulgel from both LEG and HEG showed significantly higher gel strength but similar thermal properties comparing to the fresh one. In addition, meat covered with reconstructed emulgel showed less weight loss and more stable pH and total volatile basic nitrogen (TVB-N) value, as well as stronger resistance to bacterial reproduction, especially against lactic acid bacteria. The results indicated that the microencapsulation of Eu through gelatin-based emulgel might be a convenient and effective technology for refrigerated meat preservation.
研究领域:
食品科学
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生物技术
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 2
·49667
·
IF 2.52
Mengting Li,Changgui Li,You Zhou,Hua Tian,Qiaoyuan Deng,Haifang Liu,Li Zhu,Xueqiong Yin
Microencapsulation is a widely-investigated technique used for the unstable material preservation since the wall materials prevent the core materials from loss and deterioration. To improve the stability of cinnamaldehyde (CAL), different microcapsule wall systems are fabricated by spray-drying, and then characterized by experimental methods to determine the most suitable wall materials. Surface morphology, encapsulation efficiency, effective loading capacity, as well as moisture absorption property are evaluated, and the results suggest that a three-matrix system of methyl cellulose (MC)/sodium alginate (SA)/MC or MC/carboxymethyl chitosan (CMC)/SA wall formulation is more suitable for CAL microencapsulation. Moreover, a novel quantitative method is also proposed to verify the most stable wall material microencapsulation. The quantitative results show that the highest activation energy (53.00 ± 2.24 kJ/mol) is observed for the MC/CMC/SA-encapsulated CAL microcapsule. Taken together, the results suggest that MC/CMC/SA wall formulation shows excellent barrier properties and is superior to other wall materials in preventing microencapsulated CAL deterioration. This study will be efficient in designing an ideal capsule for CAL microencapsulation.
研究领域:
食品科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2022
·Vol. 48
·期 3
·e202200277
·
IF 2.134
Yang-Fan Cheng,Yu-Le Yao,Dan-Yi Li,Zi-Han Li,Ying-Kang Yao
To study the effects of boron powders on the detonation performance of emulsion explosives, the explosion temperature field, shock wave parameters and explosion heat of emulsion explosives were studied. The differences of boron powders with and without microcapsule cladding on improving the explosion performance were also discussed. Experimental results showed that, when the mass ratio of boron powders increased from 0 to 20 mass %, the average explosion temperature, explosion pressure, positive impulse and explosion heat of boron-containing emulsion explosives increased at first and then decreased. When the content of boron powders was 16 mass %, the average explosion temperature, explosion pressure, positive impulse and explosion heat of emulsion explosives reached their maximum values of 2521 K, 0.0385 MPa, 7.11 Pa ⋅ s and 6335 kJ/kg, which were 22.2 %, 30.1 %, 43.0 % and 42.1 % higher than those of the pure emulsion explosive (Sample A), respectively. Furthermore, the explosion temperature, positive impulse and explosion heat of emulsion explosive with boron powder-microcapsule (Sample B5) were up to 2648 K, 7.65 Pa ⋅ s and 6694 kJ/kg, increased by 5.0 %, 7.6 % and 5.7 % when compared with those of emulsion explosive with 16 mass % boron powders (Sample B3). Therefore, micro-encapsulation technology could improve the detonation performance of boron-containing emulsion explosives, which would be helpful to the formula design of high energy emulsion explosives.
研究领域:
化学工程
·
爆炸力学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2015
·
IF 1.098
Zujin Yang,Yanxiong Fang,Hongbing Ji
Microcapsules of salicylic acid (SA) with chitosan were prepared by spray drying method. Various analytical methods were used to characterize the nature of microcapsules. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of intermolecular interactions between chitosan and SA. Particle size analysis showed that the average size of microcapsules ranged from 2 to 20 μm. Scanning electron microscopy (SEM) studies indicated that the microspheres were spherical and had a relatively smooth surface. Microbiological assay of antibacterial activity for SA and its microcapsules was measured using different bacterial strains. It was found that the antibacterial activity of SA was improved after the formation of microcapsules. The in vitro release profile showed that the microcapsules could control SA release from 1 h to 4 h. Kinetic studies revealed that the release pattern follows Korsmeyer–Peppas mechanism. Enhanced antibacterial activity of the SA microcapsules was attributed to the synergistic effects of intermolecular hydrogen-bonding interactions N–H⋯O and O–H⋯O C between SA and chitosan. It was also confirmed by quantum chemical calculation.
研究领域:
药剂学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2018
·
IF 0
Da-xia Zhang,Xian-peng Zhang,Jian Luo,Bei-xing Li,Yan Wei,Feng Liu
To reduce the amount of organic solvents in pendimethalin emulsifiable concentrate (EC), small-size microcapsules (S-MCs) and large-size microcapsules (L-MCs) were prepared with polyurea as a wall material. Petri-dish bioassays were carried out to investigate the bioactivity of formulations and the influence of both organic matter and moisture. The relationships between degradation and the biological activity of three pendimethalin formulations in the soil were investigated, and field experiments were executed to verify the laboratory results. The laboratory tests showed the following: (1) the bioactivity of EC and S-MCs was similar and greater than that of L-MCs; (2) organic matter could reduce the bioactivity of MCs and EC, and the impact of organic matter on L-MCs was greater; (3) increased soil moisture content had no significant effect on the bioactivity of EC but slightly reduced that of the MCs; and (4) the L-MCs showed significantly more prolonged residual and effective persistence in the soil than did EC and S-MCs. However, the field experiments indicated that the herbicidal efficacies of L-MCs at the early and late stages were both lower than those of EC. Comprehensive analysis of the results indicated that the main reason that the herbicidal efficacy of L-MCs was lower than that of EC in the field was that L-MCs missed the optimal herbicidal periods due to the slow-release characteristics of L-MCs. The S-MCs had both similar release rates and herbicidal efficacy in the field as EC. Therefore, to develop a good pesticide formulation, the occurrence and damage characteristic of pests must be considered.
研究领域:
农业科学
·
植物保护
✓ 已验证
产品关联
DOI
PubMed
Coatings
·
2022
·Vol. 12
·期 2
·166
·
IF 3.236
Guifeng Xiang,Jing Tu,Heng Xu,Jie Ji,Li Liang,Haozhe Li,Haoran Chen,Jingqing Tian,Xiaode Guo
In this study, we successfully manufactured polyurethane microcapsules containing isocyanate prepolymer as a core material for self-healing protection coatings via interfacial polymerization of a commercial polyurethane curing agent (Bayer L-75) and 1,4-butanediol (BDO) as a chain extender in an emulsion solution. With an optical microscope (OM) and a scanning electron microscope (SEM), the resulting microcapsules showed a spherical shape and an ideal structure with a smooth surface. Fourier transform infrared spectra (FTIR) showed that the core material was successfully encapsulated. Thermal gravimetric analysis (TGA) showed that the initial evaporation temperature of the microcapsules was 270 °C. In addition, we examined the influence of the concentration of the emulsifier and chain extender on the structure and morphology of the microcapsules. The results indicate that the optimal parameters of the microcapsule are an emulsifier concentration of 7.5% and a chain extender concentration of 15.38%. Microcapsules were added to the epoxy resin coating to verify the coating’s self-healing performance by a surface scratch test, and the results showed that the cracks could heal in 24 h. Furthermore, the self-healing coating had excellent corrosion resistance.Keywords:microcapsules;isocyanate prepolymer;coating;self-healing
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2023
·Vol. 125
·期 10
·2300015
·
IF 2.7
Juan Tian,Guilin Peng,Xiaodi Qu,Yunping Yao,Changmo Li
Thiamine (VB 1 ) is an essential water-soluble vitamin that is necessary in our daily diet. However, its instability when exposed to external factors poses a limitation on its application in the food industry. To address this issue and increase its application in fat-rich food systems, this study developed liposoluble VB 1 microcapsules via freeze-drying, utilizing β-cyclodextrin as a wall material and polyglycerol fatty acid ester as an emulsifying agent. The VB 1 microcapsules were characterized in terms of their particle size distribution, morphology, solubility, and stability in soybean oil, as well as their in vitro bioaccessibility. The results showed that the average particle size of VB 1 microcapsules was 83.73 μm with a nonuniform, somewhat wrinkled spherical structure. The solubility of the VB 1 microcapsules in soybean oil was increased to 142.86 mg kg –1 . The retention rates of VB 1 in soybean oil was found to be above 95% after 48 h of UV irradiation and 96.44% after heating for 7 days at 60°C. The presence of VB 1 microcapsules did not significant impact on the oxidation stability of soybean oil. The bioaccessibility of VB 1 in soybean oil was 82.81%. This work provides a useful and novel direction for the application of VB 1 in high-fat diets. Practical applications: VB 1 is one of the B-group vitamins that assists in maintaining normal glucose metabolism. However, it is readily inactivated when exposed to UV radiation, certain pH conditions, and other factors. In this work, the VB 1 microcapsules prepared by freeze-drying exhibited high liposolubility, stability, and bioaccessibility, rendering them suitable for applications in oil-based systems. This work not only provides a new delivery system to facilitate VB 1 supplementation in humans, but also helps to elucidate its application prospect of VB 1 in fat-rich foods, such as edible oil, butter, margarine, rich-fat dressings, and so on, thus improves the application value of VB 1 .
研究领域:
食品科学
·
营养学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）