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Synthetic mechanism diagram and transmission electron microscopy characterization of various core-shell structural composite products
The "plasma synergy" of metal-semiconductor composites has made it widely used in photocatalysis, optoelectronic devices, and lasers. Therefore, how to precisely control the synthesis of metal-semiconductor composite nanostructures has become a research hotspot.
In a two-component composite system, the core-shell nanostructure is the simplest and most effective structure. However, due to the large interface between the metal and the semiconductor, the semiconductor tends to nucleate from the core rather than the metal nanoparticle, resulting in the semiconductor cannot be uniformly wrapped on the surface of the metal nanoparticle. Accurate and controllable synthesis of metal-semiconductor composite core-shell nanostructures still faces significant challenges.
Recently, the team of the researcher Wang Dan of the Institute of Process Engineering of the Chinese Academy of Sciences teamed up with the team of associate professor Chen Hongyu of Nanyang Technological University in Singapore to use polyvinylpyrrolidone as a surfactant and through regulation: (1) nucleation and growth of shell materials; (2) The attachment process of the shell on the seeds; (3) The dispersion and aggregation process of nano seeds, and developed a method of encapsulating zinc oxide semiconductors on different seeds (including metals, oxides, polymer nanoparticles, graphene oxide, and carbon nanometers). The universal method of the surface). Moreover, this method is not limited to using zinc oxide as the outer shell, but also suitable for the outer shell of other oxides or sulfides, such as Fe3O4, MnO, Co2O3, TiO2, Eu2O3, Tb2O3, Gd2O3, beta-Ni(OH)2 , ZnS, and CdS, etc., to synthesize composite core-shell nanostructures. The results laid the foundation for the synthesis of other composite core-shell nanostructures. The results of relevant studies were published in the International Journal of the American Chemical Society (2013, 135, 9099−9110).
These related studies were funded by the Singapore Science and Technology Agency (SERC 112-120-2011) and the National Research Foundation of Singapore (CRP-4-2008-06).
Hydroxypropyl Methylcellulose Methoxyl content: With the reduction of methoxyl content, gel point raise up, water solubility reduce, surface activity decrease.
hydroxypropyl methylcellulose Methoxyl is White or similar to white powder, odorless No heat, chemical inertness, and not participate in the metabolism of human body.
hydroxypropyl methylcellulose Methoxyl HPMC used in Construction:
- Used as the water retaining agent and retarder in mortar to make it has good pumpability.
- Used as adhesives in plaster, gypsum material, putty powder or other construction materials to improve its workability and extend the operation time.
- Used as paste enhancer of ceramic tile, marble and plastic decoration and reduce usage of cement.
- HPMC water retention property can prohibit too fast dry and cracking after the slurry spraying and enhanced strength after hardening.
The molecular formula of hydroxypropyl methylcellulose is shown below
100000 Viscosity Hydroxypropyl Methylcellulose
Hydroxypropyl Methylcellulose Hpmc,100000 Viscosity Hydroxypropyl Methylcellulose,100000 Viscosity Hydroxypropyl Methylcellulose Hpmc,High Viscosity Hydroxypropyl Methylcellulose
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