Dissertation > Excellent graduate degree dissertation topics show

Fabrication and Study on Properties of Layered Double Hydroxide@ Sulfonated Polystyrene Microsphere with Controllable Morphology

Author: YangYingSheng
Tutor: XuSaiLong
School: Beijing University of Chemical Technology
Course: Applied Chemistry
Keywords: Composite metal hydroxide Cobalt ferrite Hollow microspheres Precursor Magnetic Superhydrophobic Film
CLC: TB383.4
Type: Master's thesis
Year: 2009
Downloads: 114
Quote: 0
Read: Download Dissertation

Abstract

With the development of Materials Science and Technology, scientists are trying to explore the use of chemical or physical methods to build a specific morphology and pore structure of the material, which could achieve the design of certain materials, such as the new catalyst support, macromolecular polymer separation membranes, biomedical materials and drug carriers, and ultimately regulate its application performance. The composite metal hydroxides (LDHs) are a class of synthetic anionic layered functional material having a two-dimensional structure, their shelves by the body with a positive charge balanced by the positive charge of the interlayer anion object and a portion of the water molecules. Laminates elements and the interlayer anions adjustable features can be derived functional assembly having different physical-chemical characteristics, and therefore may be used as a high-performance catalytic material, adsorbent materials, separation materials, functional additives, materials, biological materials and pharmaceutical materials. Currently, the research work in the field, LDHs class of materials is usually in powder form, so in the actual application process (such as a catalytic material, the adsorption and separation material, etc.) will produce such high pressure, mass / Fax Thermal efficiency is low and separation difficulties and other problems. Therefore, on LDHs class material morphology controllable preparation of scientific significance and practical value. The paper to the the LDHs class material morphology controllable preparation as the goal, focus on the preparation of hydrotalcite @ sulfonated polystyrene composite microspheres and its application. Specific research and experimental results are as follows: (1) in the high charge, sulfonate-modified polystyrene microspheres surface by surface nucleation and growth process in the growth of the surface of the microspheres hydrotalcite, while the formation of a uniform cladding layer, shell showed flower-like and strawberry-like structure, the thickness of the coated layer 40 to about 200 nm. The thickness and morphology of the coating layer can be adjusted by changing the concentration of the metal ions and the polystyrene microspheres; 2 the vertical alignment satisfied microstructure CoFeFe-LDHs film modified by a silane coupling agent, exhibit excellent super- hydrophobic properties, the static contact angle with water of up to 157.7 °. 3 ScS hydrophobic treatment system after the talc CoFeFe-LDHs water heterogeneity microspheres its anti-acid properties, the results showed that: having a certain acid in an aqueous solution of pH = 2, the static contact angle of up to 158.8 °, 150s about the contact angle reaches a steady contact angle of 141 °. In an aqueous solution of pH = 12 and the hydrotalcite is a dissolved recrystallization process. In both cases the fundamental reason hydrotalcite fluoride acid and alkali resistance change. (4) by means of SEM characterization reveals LDHs film the surface modification CoFeFe-superhydrophobic properties of the underlying reasons: LDHs film prepared under low temperature conditions loose and a larger gap between the grains formed satisfied micro-composite structure; hydrophobic satisfied that the film after processing the micro-structure is substantially no change; the waterdrop film interface able to accommodate more air balloon, which exhibit excellent hydrophobic properties. Composite microspheres on CoFeFe-LDHs @ sPS program the warming calcined preparation CoFe ₂ O ₄ hollow microspheres through the realization of the metal elements doped hydrotalcites of spinel magnetic regulation;

Related Dissertations

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net Mobile