Dissertation > Excellent graduate degree dissertation topics show

Preparation of Molecular Imprinting Polymer on Crosslinked Polyvinyl Alcohol Microspheres for Cholic Acid and Research of Specific Binding Property

Author: LuJinHua
Tutor: GaoBaoJiao
School: University of North
Course: Applied Chemistry
Keywords: Cholic acid PVA microspheres Polyvinylamine Imprinted Surface imprinting Graft polymerization
CLC: O631.3
Type: Master's thesis
Year: 2009
Downloads: 299
Quote: 0
Read: Download Dissertation

Abstract


Bile acids are contained in animal bile main active ingredient (a major constituent of acid), belongs to a class of strong hydrophobic steroid. Bile acid in the digestion and absorption of lipids and cholesterol metabolism plays an important role in homeostasis. Bile acids from the animal to extract various components (such as cholic acid, chenodeoxycholic acid, ursodeoxycholic acid, etc.) have different pharmacological activity. Further, by measuring human bile acid concentration of each component, hepatobiliary diseases can be diagnosed. In this study, our group established a novel surface molecular imprinting technique to polymeric microspheres as a substrate was prepared by acid imprinted materials to study its molecular recognition mechanism for bile acids. The results of this study, for the enrichment and detection of bile acids has important application value, a similar study has not been reported in the literature. Firstly, vinyl acetate (VAc)-based monomer, divinylbenzene (DVB) as crosslinking agent, polyvinyl alcohol (PVA) as dispersing agent, were prepared by suspension polymerization crosslinked microspheres CPVAc; emphasis on the the amount of dispersant, stirring speed, oil-water two-phase ratio, NaCl dosage on the formation of crosslinked microspheres and size were investigated. The use of methanol for microsphere CPVAc alcoholysis reaction, was prepared polyvinyl alcohol (PVA) crosslinked microspheres CPVA. The results showed that: CPVA crosslinked microspheres depends on the physical form of the precursor microspheres CPVAc morphology and particle size. In the suspension polymerization system, the amount of dispersant, the stirring speed is compared with the oil-water two crosslinked microspheres prepared affecting major factor when the amount of dispersing agent is too small (lt; 0.3%), the stirring rate is too slow (lt; 200rpm), oil-water volume ratio is too large (VO / VW gt; 1:4), the total polymerization system can not occur in both the process into a ball. Control of various reaction conditions for suspension polymerization, good sphericity can be prepared, the particle size can be regulated crosslinked microspheres CPVAc. Impact microspheres CPVAc alcoholysis reaction the reaction temperature is the main factor, suitable temperature is 40 ℃, 15 h reaction can reach 92% alcohol solution. In this study obtained CPVA microspheres crosslinked PVA, based on the ammonium cerium sulfate as an initiator, using an aqueous solution polymerization system, implemented in an acidic medium, acrylamide (AM) in the crosslinked PVA microspheres ( CPVA) surface graft polymerization, graft prepared microspheres PAM / CPVA, focuses on the graft polymerization of various factors on the impact of the law, discusses the cerium initiated graft polymerization mechanism. Experimental results show that the Ce (Ⅳ) under salt oxidation, containing a large number of hydroxy CPVA microspheres may produce free radicals, to achieve a smooth acrylamide radical graft polymerization. Grafting degree of PAM depends first on the concentration of sulfuric acid in an aqueous medium, the degree of grafting increases with the concentration of sulfuric acid at first increases and then decreases the variation, when the H ion concentration of 0.36mol / L when, PAM graft the highest, and acid concentration on the grafting degree of reflection of cerium initiated graft polymerization of the microscopic mechanism. Ce4 initiator salt concentration is too large, it will promote the oxidation of the termination process, reducing the degree of grafting, the appropriate concentration of Ce4 5.98 × 10-3mol / L. In the graft polymerization, the monomer concentration of acrylamide and the reaction temperature will also affect the graft polymerization. The study also particle surface by grafting polyacrylamide Hofmann degradation, surface grafting of polyethylene was obtained amine (PVAm) grafted crosslinked microspheres PVAm / CPVA. Hofmann degradation by infrared spectroscopy on the chemical structure of the polymer before and after reaction were characterized by chemical analysis method Hofmann degradation of the surface of the microspheres crosslinked amine content were determined mainly inspected NaOCl concentration, NaOH concentration, reaction temperature and reaction time on the Hofmann degradation reaction. Experimental results show that the reaction can be successfully prepared by Hofmann degradation of polyethylene grafted amine microspheres PVAm / CPVA, optimum reaction conditions: a temperature of -3 ℃; n (NaOH) / n (PAm) = 30:1; n (NaOCl) / n (PAm) = 1.4:1; reaction time 11h. Carried out under suitable conditions Hofmann degradation reaction microspheres PVAm / CPVA amine content can reach the surface of 0.002mol / g. This more in-depth study of the graft particles PVAm / CPVA in water / ethanol mixed solution for bile acid adsorption properties and adsorption mechanism. Experimental results show that the graft particles PVAm / CPVA virtue of electrostatic forces and hydrogen bonding interactions synergy of bile acids will produce a strong adsorption, which for the preparation of acid molecularly imprinted (MIP) material foundation. Finally, this study by our group to establish a new type of molecular surface imprinting technique to acid molecule as a template, using glutaraldehyde as crosslinking agent, chemically bonded on the surface of the polyvinyl alcohol polymer chains were PVAm acid molecules surface imprinting, imprinted material prepared by acid surface MIP-PVAm/CPVA; static and dynamic two methods studied MIP-PVAm/CPVA on bile acid binding properties, and cholesterol contrast material was investigated mainly imprinting conditions on imprinted materials combined selection performance. Experimental results show that the bile acid MIP-PVAm/CPVA imprinted material having a specific combination of selectivity with respect to cholesterol, before blotting, non-imprinted material PVAm / CPVA selection of bile acid absorption coefficient is only 1.314, and after blotting , imprinted material MIP-PVAm/CPVA adsorption selectivity coefficient is increased to 11.231. Further, imprinted material eluted with excellent performance MIP-PVAm/CPVA.

Related Dissertations

  1. Preparation, Evaluation, and Application of Several Natural Product Molecularly Imprinted Polymers,R284.1
  2. Synthesis and Resolution Property of N-(9-Fluorenylmethoxycarbonyl)-D-Tryptophan and D-Phenylalanine Imprinted Polymer,O631.3
  3. Study on Synthetic of BINOL, Amino Acid and Derivatives Molecularly Imprinted Polymers and Their Application in the Chiral Resolution,O631.3
  4. Molecularly Imprinted Polymer Microspheres and Evaluation,O631.3
  5. For drug ingredients isolated molecularly imprinted polymer microspheres preparation , properties and application of testing,O631.3
  6. Imprinted Polymer Preparation and application of solid-phase extraction,O631.3
  7. Preparation of Phenol Molecularly Imprinted Polymers on the Surface of Silica and Its Application in DGT Technique,O621.2
  8. Interfacial polymerization preparation of small aperture composite ultrafiltration membrane and its performance,TB383.2
  9. Ag / CTS imprinted gel Preparation and properties of the ball,TQ424
  10. Research of Molecular Imprinted Electrochemical Sensor for Paracetamol,TP212.2
  11. Preparation of Dummy Template Imprinted Polymers at Surface of Silica Submicroparticles for the Selective Extraction of Trace Bisphenol a from Water Samples,X832
  12. Preparation of Quinolones Molecularly Imprinted Polymer Microspheres and Study of Its Specific Adsorption Performance,O631.3
  13. Preparation and Characteristics of Silica Surface Molecularly Imprinted Polymer for Gasoline Desulfurization,O631.3
  14. Research on the Synthesis and Properties of EGCG-molecularly Imprinted Polymer,O631.3
  15. Preparation of Molecularly Imprinted Polymers Via Atom Transfer Radical Polymerization,O631.3
  16. Study on Preparation of Norfloxacin Molecularly Imprinted Polymers and Its Application in Solid Phase Extraction Technology,O631.3
  17. Study on Preparation and Application of estradiol-imprinted Microspheres Using Modified Precipitation Method,O631.3
  18. Synthesis and Molecular Recognition of Flavonoids Functional Factors of Traditional Chinese Medicines-Imprinted Polymer,O631.3
  19. Study on Synthesis and Property of Water-soluble Polyelectrolyte,O631.3
  20. Study on the Preparation Methods and Recognition Properties of Fluoroquinolones-Molecularly Imprinted Sol-Gel Sorbents,TQ424
  21. Fabrication of Chlortoluron and Oxytetracycline Sensors Based on Molecular Imprinted Films,TP212.2

CLC: > Mathematical sciences and chemical > Chemistry > Polymer chemistry ( polymer ) > Polymer physics and physical chemistry of polymers > The chemical nature of polymers
© 2012 www.DissertationTopic.Net  Mobile