Papers by Keyword: Microcapsule

Abstract: Microcapsules containing n-octadecane (MicroC18) with n-octadecyl methacrylate (ODMA)-methacrylic acid (MAA) copolymer shell were fabricated through phase separation method, in which the shell-forming copolymers synthesized by free-radical solution polymerization. Meanwhile, theses copolymers were employed as the surfactant during microencapsulation. The crystallization temperature and crystallinity degree of comb-like copolymer display a gradual decrease with an increase the molar ratio of MAA. MicroC18 with spherical profiles and the diameter ranging from 3 to 20 μm were fabricated. In addition, the system pH value plays an important role in the formation process of microcapsules and the optimum value of pH in the range of 8.5-10.5.

Abstract: Carbon nanotubes grafted with stearyl alcohol (CNTs-SA) was used to enhance the thermal conductivities of the microcapsules. Differential Scanning Calorimeter (DSC) and thermogravimetry (TG) analysis method are employed to measure thermal properties of the prepared MicroPCM containing the grafted CNTs (MicroPCM/CNTs-SA). The results indicated the phase change temperature and latent heat of MicroPCM/CNTs-SA was 26.2°C and 47.7J/g. An increase in thermal conductivity, thermal stability of MicroPCM/CNTs-SA was observed. After 100 heating and cooling cycles, MicroPCM/CNTs-SA still had better durability and thermal stability.

Abstract: The water-based gravure ink does not contain volatile organic solvent, which is an environmentally friendly ink. But slow drying is a bottleneck of water-based gravure ink in use. Proposed the water in Water-based gravure ink reacts with temperature control microcapsule drying agent when heated in drying box of gravure printing machine to increase the ink drying speed. Designed preparation purification and drying methodthe of calcium oxide microcapsules, which surface is coated with hydrophobic compound and surfactant. The coating layer of Water-based gravure ink drying agent has good water resistance below 60°C, which will drop from the surface of the calcium oxide in the process of temperature continues to rise. Use the rheometer to test the rheology of water-based gravure ink contain microcapsule drying agent, characterization of the drying effect of the microcapsule drying agent based on the change in viscosity of the ink. Experimental results show that, the excitation temperature of the drying agent is 40°C. The Prepared temperature control microcapsule drying agent can effectively improve the drying speed of the water-based gravure printing ink.

Abstract: Polymer phase change microcapsules were prepared through microwave-assisted emulsion polymerization, with the core of hexadecane, the shell of styrene, the emulsifier of sodium dodecyl sulfate, the initiator of potassium persulfate. A few of key factors which can influence the thermal performance and the encapsulation, such as emulsifiers, initiators, temperature and reaction time were investigated. FTIR and DSC were employed to characterize the structure, the phase transition temperature and latent heat.

Abstract: The biodegradable microcapsules based ethyl cellulose (EC) for a controlled delivery of Argy Wormwood solution (AWS) were prepared by emulsionsolvent evaporation method using ethyl acetate as solvent. This study examined the effect of the ratios of core to shell on the size of microcapsules. SEM images of microcapsules showed uniform spherical structures with smooth surfaces with a particle size distribution of 100nm2μm. Core-shell, hetero-structures were confirmed using optical micrograph. The chemical structure of the microcapsules was determined by FTIR.

Abstract: Hexadecane microcapsule phase change materials were prepared by the in-situ polymerization method using hexadecane as core materials, urea-formaldehyde resin and urea-formaldehyde resin modified with melamine as shell materials respectively. Effect of melamine on the properties of microcapsules was studied by FTIR, biomicroscopy (UBM), TGA and HPLC. The influences of system concentration, agitation speed and mass ratio of wall to core were also investigated. The results indicated that hexadecane was successfully coated by the two types of shell materials. The addition of melamine into the urea-formaldehyde resin microcapsule reduced microcapsule particle size and microencapsulation efficiency. The influences of factors such as system concentration, agitation speed and mass ratio of wall to core to different wall materials microcapsules presented different variety trends of the microcapsule particle size.

Abstract: Taking the advantages of the unique features of phase change materials (PCM),it is possible to fabricate smart thermoregulated textiles through the effective combination of PCM and textiles. In this study, the candidates of PCM and its requirements suitable for the textiles were summarized, various manufacturing technologies of microPCMs and smart thermo-regulated textiles were reviewed. For the applications on a large scale, further research need to be conducted in aspects including new types of PCM, stability and durability of smart textiles, the advanced fabricating technology, performance of PCM microcapsules and its novel applications in textile industry, and relevant evaluation method and standard for the smart textiles.

Abstract: The design of new technologies for treatment of human disorders is a complex and difficult task. The aim of this article is to explore state of art discussion of various techniques and materials involve in cell encapsulations. Encapsulation of cells within semi-permeable polymer shells or beads is a potentially powerful tool, and has long been explored as a promising approach for the treatment of several human diseases such as lysosomal storage disease (LSD), neurological disorders, Parkinsons disease, dwarfism, hemophilia, cancer and diabetes using immune-isolation gene therapy.

Abstract: The self-healing polymer material which was embedded microcapsules possesses the ability to heal cracks automatically. The microcapsules were synthesized by in-situ polymerization in an oil-in-water emulsion with urea and formaldehyde as the raw shell material,and epoxy resin (E-51)/ xylene as the core material. The impact of stirring speed on the morphology and particle size of synthetic microcapsules were discussed by optical microscopy (OM), scanning electron microscopy (SEM), and Fourier-transform infrared spectrometer (FTIR).Microcapsules of 400~1500 um in diameter were produced by appropriate selection of agitation rate in the range of 300~600 r/min.

Abstract: By some assumed conditions and by Fick first law (first used for release behavior of microcapsules), the release dynamic equation of idealized microcapsules in liquid phase was established. With extraction method and spectrophotometer, the light absorbance of extracted liquid was measured, the release dynamics in liquid phase and some relatively release parameters were acquired. The experiment indicated: the release behavior of the CVL core permeated from the wall of microcapsules into the liquid phase matched with zero-order release equation basically.