Dissertation > Excellent graduate degree dissertation topics show

Synthesis of Novel Chitosan Derivatives and Surface Functionalization of Titanium with HACC

Author: WangLing
Tutor: GuoShengRong
School: Shanghai Jiaotong University
Course: Pharmacy
Keywords: quaternary chitosan derivatives phosphonium chitosan derivatives titanium surface modification x-ray photoelectron spectroscopy (XPS)
CLC: R94
Type: Master's thesis
Year: 2010
Downloads: 111
Quote: 0
Read: Download Dissertation

Abstract


Chitosan, a well-known abundant natural polycationic macromolecule with good biodegradability, biocompatibility and so on, gets much attention currently for biomedical application.Firstly, varies of 2-Hydroxypropyltrimethyl ammonium chloride chitosans (HACC) with different degree of substitution (DS: 6%, 18%, 37%, 54% and 81%) were synthesized by the reaction of chitosan with glycidyltrimethylammonium chloride (GTMAC), and characterized by FT-IR and 1H-NMR spectroscopy. Their properties such as water solubility, aqueous solution stability upon pH and moisture absorption ability were studied, following with the film-forming capability and the antibacterial property of films. Results indicated that the water solubility, aqueous solution stability upon pH and moisture absorption ability increased with increasing DS of HACC. Additionally, HACC films, prepared by tape casting with their dilute solutions, were presented as transparent films with favorable mechanical performance and better antibacterial property against Staphylococcus aureus and Escherichia coli than chitosan film.Secondly, HACC functionalized titanium was prepared by treating the pristine titanium with piranha acid oxidation, silanization procedure, glutaraldehyde reaction and HACC (DS: 18%) deposition successively. Each kind of chemical treated titanium was characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared attenuated total reflection (FT-IR/ATR). The results showed that with each reaction occurred, the atomic ratio of C/Ti and O/Ti gradually increased. Following the reaction of glutaraldehyde treated titanium with HACC, the atomic ratio of N/Ti rised from 0.212 to 1.088. With each reaction occurred, the content of O 1s attributed to TiO2 became smaller and smaller, from 81%, 72%, 61% to 40%. Also with each reaction carried out, the electron peak of Ti 2p at 453.4 eV due to Ti base gradually turned smaller and the peak almost diappearred after the titanium was treated with glutaraldehyde and HACC. Additionally, series infrared absorption bands were observed on the surface of HACC funtionalized titanium, including 3365cm-1 (-OH), 1664cm-1 (Amide I), 1165cm-1 (νas, C-O-C bridge) and the absorption bands between 958cm-1and 1155cm-1 (skeletal vibrations involving the C-O stretching of saccharide structure of HACC). All these results indicated that HACC was successfully covalently attached to medical titanium surfaces.Eventually, novel Water Soluble Phsophonium Chitosan Derivatives (WSPCS) were synthesized with differing degree of substitution (3.6% and 4.2%) of quaternary phosphonium by reacting chitosan with (2-Carboxyethyl) triphenylphosphonium chloride in a homogeneous system. At the same time, novel Organo Soluble Phosphnium Chitosan (OSPCS) were prepared with differing degree of substitution (54.5% and 81.7%) using chitosan-sodium dodecyl sulfate polyelectrolyte/surfactant complex in an organo system. All these compounds were characterized by FT-IR, 1H-NMR, 31P-NMR and x-ray diffraction (XRD). The results suggested that both WSPCS and OSPCS contained element of phsophonium. The crystallinity of not only WSPCS but also OSPCS was significantly influenced by the introduction of triphenylphosphonium group to chitosan backbone. WSPCS also showed improved water solubility, while the resulting OSPCS showed enhanced organo solubility compared to original chitosan.

Related Dissertations

  1. Studies on Synthesis, Characterization and Properties of Fe-V Co-doped TiO2 Catalyst,O614.411
  2. Characterization and mechanism of the titanium dioxide surface envelope,TQ621.12
  3. Preparation of Crop Stalk-Based Sorption Materials with High Performances and Their Applications for Pah Removal from Water,X712
  4. Synthesis and Biocompatibility of different types of hydrophilic surface - modified polyurethane,R318.08
  5. Iron, lanthanum -doped nano TiO \u003csub\u003e 2 \u003c/ sub\u003e Preparation and photocatalytic properties,O614.411
  6. Clinical Analysis with Rigid Internal Fixation in 162 Cases Mandibular Fractures,R782.4
  7. Influence of Various PH and the Treating Time on Mechanical Property and Surface Structure of Ni-ti Orthodontic Wire,R783.5
  8. Polyaniline / short fiber reinforced natural rubber properties,TQ330.1
  9. Phosphate modification of nano- TiO 2 Photoelectrochemical Properties of the,TB383.1
  10. Construction of Multi-responsive Gene Vector Via Layer-by-Layer Assembly,TB383.1
  11. Preparation of High-Titanium Ferroalloy by Electrochemical Reduction of High Titanium Slag in Molten Salt,TG146.23
  12. Study on Laser Surface Modification of Two Kinds of Super-alloys,TG174.4
  13. Preparation of Highly Reactive Anatase Titanium Dioxide and Its Application in Photocatalytic Hydrogen Generation,TQ116.2
  14. Study of Titanium-modified Phenolic Resins,TQ323.1
  15. Optimum to the Electrolyte Composition of New Titanium Smelting Method and Its Application to Titanium Alloy Materials,TG171
  16. Study on the Preparation and Photocatalytic Activity of Titanium Dioxide Nanoparticles,O643.36
  17. Atmospheric Pressure Plasma Surface Modification of Carbom Fibers and Numerical Simulation of the Discharge,TQ342.742
  18. Preparation of Zeolite Doping Nano-TiO2 and Research of the Photocatalytic Properties,TB383.1
  19. Study on Modification of PBO Fibers by Atmospheric Pressure Plasma,TS195.6
  20. A Study of Photocatalysis Degradation of Polybrominated Diphenyl Ethers (PBDEs),X70
  21. Analyse of Expansive Open-door Laminoplasty with Titanium Mesh Cages and Laternal Mass Internal Fixation by Posterior Approach of Cervical Spondylotic Myelopathy,R687.3

CLC: > Medicine, health > Pharmacy > Pharmacy
© 2012 www.DissertationTopic.Net  Mobile