Characterization of a pH/Temperature-Sensitive Hydrogel Synthesized at Different pH and Temperature Conditions

pH/온도-동시 민감성 Hydrogel의 합성조건에 따른 특성 연구

  • Published : 2000.12.01

Abstract

A hydrogel, poly(N-isopropylacrylamide-co-N, N-dimethylaminopropylmethacrylamide), sensitive to both pH and temperature, was synthesized and characterized at $^13∼23{\circ}C$ and pH of 10.3∼12.3. The gel was more transparent and mechanically stronger at lower preparation temperature and pH. Large pores observed in scanning electron microscope seem to be responsible for the lower biomolecular separation efficiency. The lower critical solution temperature (LCST) decreased at a higher polymerization temperature. At $25^{\circ}C$, which is lower than the LCST, the gel was swollen regardless of the solution pH. At $40^{\circ}C$, however, the gel was swollen at neutral and acidic pHs even though the temperature was higher than the LCST. The gel collapse pH, defined as the point at which the gel made its largest volume decrease per unit pH increment, increased as the gel preparation temperature increased.

온도 및 pH에 동시에 민감한 하이드로젤 poly(N-isopropy­l lacrylamide-co-N,N-dimethylaminopropy Imethacrylamide)을 온도 (13, 15.5, 18, 20.5 및 $23^{\circ}C$)와 pH (10.3, 11.3 및 12.3)를 달리 하여 합성하고 이 젤들의 외형, 기계적 강도, 젤 표면모양, LCST, 수축 pH 및 젤의 팽윤 특성을 연구하였다. 합성온도 및 합성 pH가 낮을수록 젤의 외형은 투명하였 고 기계적 강도는 높았다. SEM 관찰 결과 단백질 보다 더 큰 pore들 때문에 분리효율이 감소되는 것으로 사료된다. 합 성온도나 합성 pH의 증가는 LCST를 낮추었다. 외부온도가 LCST보다 낮은 $25^{\circ}C$ 에 서는 모든 합성온도와 합성 pH에 대 하여 젤은 전 pH에 걸쳐 팽윤된 상태에 있었다. $40^{\circ}C$에서는 LCST보다 높은 온도임에도 불구하고 poly (NIPAAm-co­D DMAPMAAm) 하이드로젤은 pH가 중성 및 산성 영역에서 팽윤되었다. 합성온도가 증가함에 따라 젤 부피가 가장 큰 폭으로 변하는 수축 pH가 더 높아졌다.

Keywords

References

  1. Chem. Eng. Sci. v.42 Temperature-sensitive Gels as Extraction Solvents Freitas, R. F. S.;E. L. Cussler
  2. Scientific American Gels Tanaka, T.
  3. Science v.218 Collapse of Gels in an Electric Field Tanaka, T.;I. Nishio;S. T. Sun;S. Ueno-Nishio
  4. Chem. Eng. Sci. v.45 Pressure-dependent Phase Transitions in Hydrogels Lee, K. K.;M. Marchetti;E. L. Cussler;M. A. McHugh
  5. Biotechnol. Prog. v.8 Concentrating Cellulases from Fermented Broth Using a Temperature-sensitive Hydrogel Park, C.-H.;I. Orozco-Avila
  6. J. of Control. Rel. v.4 Thermally Reversible Hydrogels: Ⅲ. Immobilizatoin of Enzymes for Feedback Reaction Control Dong, L. C.;A. S. Hoffman
  7. Biotechnol. Bioeng. v.35 Immobilization of Arthrobacter simplex in a Thermally Reversible Hydrogel: Effect of Temperature Cycling on Steroid Conversion Park, T. G.;A. S. Hoffman
  8. J. of Control. Rel. v.4 Thermally Reversible Hydrogels: Ⅱ. Delivery and Selective Removal of Substances from Aqueous Solutions Hoffman, A. S.;A. Afrassiabi;L. C. Dong
  9. Macromolecules v.25 Mutual Influence of pH and Temperature on the Swelling of Ionizable and Thermosensitive Hydrogels Feil, H.;Y. H. Bae;J. Feijen;S. W. Kim
  10. J. Appl. Pol. Sci. v.46 Synthesis an Characterization of pH-and/of Temperature-sensitive Hydrogels Park, T. G.;A. S. Hoffman
  11. Polymer v.37 Partitioning of Proteins and Small Biomolecules in Temperature- and pH-sensitive Hydrogels Sassi, A. P.;A. J. Shaw;S. M. Han;H. W. Blanch;J. M. Prausnitz
  12. Biotechnol. Prog. v.9 Concentrating Cellulases Using a Temperature-sensitive Hydrogel: Effect of Gel Particle Size and Geometry Park, C.-H.;I. Orozco-Avila
  13. Biotechnol. Tech. v.9 Prediction of Hydrogel Pore Size by Pulse NMR and Neural Network Han, J.;R. R. Ruan;C.-H.Park
  14. Macromol. Rapid Comm. v.17 Hysteresis in the Glucose Permeability versus pH Characteristic for a Responsive Hydrogel Membrane Baker, J. P.;R. A. Siegel
  15. Polymer v.37 Partitioning of Proteins between and Aqueous Solution and a Weakly-ionizable Polyelectrolyte Hydrogel Wu, J. Z.;A. P. Sassi;H. W. Blanch;J. M. Prausniz
  16. Anal. Chem. v.67 Methylphenazonium-modified Enzyme Sensor Based on Polymer Thick Films for Subnanomolar Detection of Phenols Kotte, H.;B. Grundig;K. D. Vorlop;B. Strehlitz;U. Stottmeister
  17. Food Technol. v.43 Isolated Soy Protein Production Using Temperature- sensitive Gels Trank, S. J.;D. W. Johnson;E. L. Cussler
  18. Pharm. Res. v.13 Preparation and Characterization of Freeze-dried Chitosan poly(ethylene oxide) Hydrogels for Site-specific Antibiotic Delivery in the Stomach Vijay. R, Patel;Mansoor. M. Amiji
  19. J. Macromol. Sci. -Chem. v.A2 Solution properties of poly(N-isopropylacrylamide) Heskins, M.;J. E. Guillet
  20. Pol. Gels and Network v.3 The Effect of Preparation Temperature on Some Properties of a Temperature-sensitive Hydrogel Rathjen, C. M.;C.-H. Park;P. R. Goodrich;D. D. Walgenbach
  21. Lower Critical Solution Temperatures of Aqueous Copolymer of N-isopropylacrylamide and Other N-substituted Acrylamides Priest, J. H.;S. L. Murray;R. J. Nelson;A. S. Hoffman
  22. J. Chem. Phys. v.97 Quasielectric Light Scattering Study of the Formation of Inhomogeneities in gel Suzuki, Y.;Nozaki, K.;Tetsuya, Y.;Kiichi, I.;Nishio, I.