Dissertation > Excellent graduate degree dissertation topics show

The composite hydrogel the PNIPA/Fe_3O_4 irradiation Preparation and Characterization

Author: ZhangHongRu
Tutor: ZhuChengShen；HeSuQin
School: Zhengzhou University
Course: Materials Science
Keywords: Poly (N- isopropyl acrylamide ) Fe3O4 Temperature-sensitive Magnetic Release
CLC: TB332
Type: Master's thesis
Year: 2009
Downloads: 78
Quote: 0
Read: Download Dissertation

Abstract


The hydrogel is hydrophilic without water-soluble polymer material having a three-dimensional network structure. Smart hydrogel is a hydrogel to external stimuli such as temperature, pH, light, ionic strength, magnetic field and electric field can produce a sensitive response behavior. This unique response of smart hydrogels, controlled drug delivery, sensors, memory devices switch, tissue engineering has good application prospects. The magnetic hydrogel can be used in controlled drug delivery, targeted drug delivery and other areas. The traditional method of synthesis of the methods most used chemical initiator, residual initiator present in the product. This work was the use of radiation polymerization prepared PNIPA / the Fe 3 O 4 magnetic composite hydrogel, its sensitivity to temperature and magnetic response. N-isopropyl acrylamide (NIPA) as a temperature-sensitive polymer monomer to Fe 3 O 4 magnetic source, using 60 / sup> Co gamma-ray irradiation-induced polymerization method PNIPA / Fe 3 O 4 magnetic composite hydrogel. Magnetic composite hydrogel swelling properties, magnetic properties. Add findings the nano Fe 3 O 4 magnetic particles, reducing the equilibrium swelling ratio of the hydrogel. In order to give hydrogel magnetic energy, rather than reduce its swelling properties of the work Induced polymerization method the PNIPA / Fe 3 O 4 as magnetic porous composite a hydrogel. The swelling properties of the porous hydrogel to investigate the mechanism of swelling. Research magnetic composite hydrogel, porous composite hydrogel swelling properties at the same time, the performance of their release. The main contents and conclusions are as follows: (1) the use of chemical co-precipitation Preparation of Nano Fe 3 the O 4 magnetic particles, sodium citrate modified Fe 3 O 4 magnetic particles. By XRD analysis of product structure, in preparation Fe 3 O 4 was spinel structure, calculated by the Debye-Scherrer equation product particle size of approximately 30 nm were successfully prepared the nano Fe 3 O 4 magnetic particles. The use of FT-IR were characterized before and after the sodium citrate modified Fe 3 O 4 magnetic particles modified the Fe 3 O 4 magnetic particle spectrum absorption peak at 2980cm -1 at the-CH 2 the stretching vibration, 879cm -1 , 1046cm -1 at the CO single bond stretching vibration. This shows that the use of sodium citrate modified Fe 3 O 4 magnetic particles effectively. Use the PPMS testing system testing homemade nano-Fe 3 O 4 magnetic determine Fe 3 O 4 hysteresis loop. Homemade nano-magnetic Fe 3 the O 4 hysteresis loops were not coercive force and residual magnetization of the particles with superparamagnetic saturation magnetization Ms of about 65 emu / g. (2) 8kGy, 15kGy and 22kGy dose radiation dose rate 5kGy / h at success irradiation prepared PNIPA hydrogel the the PNIPA / Fe 3 O 4 < / sub> composite hydrogel. Get the nano magnetic Fe 3 O 4 particles uniformly dispersed PNIPA / Fe 3 O 4 composite hydrogel. The gel fraction of hydrogel increases with irradiation dose increases. Fe 3 O 4 Add to reduce the equilibrium swelling ratio of the hydrogel, but the the hydrogel lowest critical phase transition temperature of no effect. And with Fe , 3 O 4 content increases, the equilibrium swelling ratio of the composite hydrogel reduced. With the radiation dose increases the compressive strength of the composite hydrogel increases Fe 3 O 4 the join has little effect on the compressive strength of the hydrogel. The use of the the PPMS test system testing the magnetic properties of the composite hydrogel external magnetic field-20000Oe 3 O 4 content increases. (3) by adding pore-forming agent PEG Irradiation porous magnetic composite hydrogel. The composite hydrogel obvious pore structure the composite hydrogel aperture holes of different sizes. Maximum pore size of about 40μm. PEG porogen Add to improve the equilibrium swelling ratio of the composite hydrogel, the equilibrium swelling ratio of the hydrogel increased with increasing the content of the pore-forming agent, as the pore-forming agent content of up to 20% when equilibrium swelling rate approximately 32%. Pore-forming agent to join, the hydrogel lowest critical phase transition temperature by about 33 ° C to 37 ° C, PNIPA PNIPA / Fe 3 O 4 composite hydrogel The plastic water loss rate were increased by approximately 52%, 75%. Molecular size of the pore-forming agent swelling properties of the hydrogel. () Fe 3 O 4 of join to reduce ordinary hydrogel release amount and the release rate in the early stages of drug release, but did not change the release reached the balance of time, the basic release 4h after equilibrium is reached. The pore-forming agent to be added significantly improve the release amount of the hydrogel ordinary hydrogel release after release 4h basic equilibrium the porous hydrogels release amount has been slowly increasing.

Related Dissertations

  1. Research on Magnetic Field Sensor Based on GMI Effect and Geomagnetic Matching Algorithm,P318
  2. Research on the Structure and Characteristics of Permanent Magnetic Coupling,TH139
  3. Grid-Side Converter Control and Wind Turbine Emulator in Direct Drive Wind Power System,TM46
  4. The Experimental Study of Semiconductor Laser Radiation and 5-FU Sustained Release Repressed Oral Malignant Tumor Cell,R739.8
  5. Measurement and Reconstruction of Ion Channel Current for Cell Membrane in Rat’s Cerebral Cortex,Q42
  6. Structural Design & Prototype Development on Deepwater Pipelines Position Measuring Device,TE973
  7. Healthy Chinese central olfactory structures related to MRI volume and olfactory function with age correlation,R445.2
  8. Progressive supranuclear palsy clinical and magnetic resonance imaging characteristics of,R741
  9. Preliminary Study of the MRI Diagnosis and Differential Diagnosis in Multiple System Atrophy , Progressive Supranuclear Palsy and IPD,R445.2
  10. Chemical Modification and Application of Ginseng Organic Complex Fertilizer,S567.51
  11. Study on Drug Delivery Systems of Visible and Near Infrared Light-sensitive O-nitrobenzyl Prodrugs,TQ460.1
  12. Integrate Ka-band T / R module,TN859
  13. Research of Metering Standard Device in Industry of Heavy Direct Current,TM835.2
  14. 3D-MRI Investigation on Fetal Surface Malformations Vs.2d-MRI and 3D-US,R714.5
  15. Application of 3.0T Magnetic Resonance Neurography in Diagnosing Spinal Nerves Diseases,R745
  16. Fraud of Bill of Lading and Study on Its Leagal Strategies,D996.1
  17. Research about Cognate Words of Shi Da,H136
  18. The Clinical Magnetic Resonance Imaging Findings and Expression of hepcidin mRNA in Livers of a Hereditary Hemochromatosis Pedigree,R589
  19. Comparative Study of Clicking Temporomandibular Joint Before and after Being Cured by MRI,R445.2
  20. Study of the Structure of Wall-Inspecting Robot on Chemical Container in Service,TP242
  21. Organic sulfur chelating agent solution for flue gas desulfurization stabilization of mercury ions,X703

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Composite materials > Non-metallic composite materials
© 2012 www.DissertationTopic.Net  Mobile