Synthesis and characterization of multiresponsive core-shell microgels

被引:496
作者
Jones, CD [1 ]
Lyon, LA [1 ]
机构
[1] Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA
关键词
D O I
10.1021/ma001398m
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
We report the synthesis and characterization of temperature and pH responsive hydrogel particles (microgels) with core-shell morphologies. Core particles composed of cross-linked poly(N-isopropylacrylamide) (p-NIPAm) or poly(NIPAm-co-acrylic acid) (p-NIPAm-AAc) were synthesized via precipitation polymerization and then used as nuclei for subsequent polymerization of p-NIPAm-AAc and p-NIPAm, respectively. The presence of a core-shell morphology was confirmed by transmission electron microscopy (TEM). Thermally initiated volume phase transitions were interrogated via temperature-programmed photon correlation spectroscopy (TP-PCS) as a function of solution pH. The p-NIPAm-AAc core hydrogel displays both a strong temperature and pH dependence on swelling. However, both p-NIPAm-AAc (core)/p-NIPAm (shell) and p-NIPAm (core)/p-NIPAm-AAc shell) particles display a more complex pH dependence than the homogeneous particles. Specifically, a multistep volume phase transition appears when the AAc component becomes highly charged at a high pH. It is apparent from the measured deswelling curves that a portion of the particle swelling behavior is dominated by p-NIPAm, regardless of its location in the particle. However, deswelling behavior that is due to a mixture of p-NIPAm-AAc and p-NIPAm is evident, as well as a regime that is largely attributed top-NIPAm-AAc alone. Small differences in the effect of pH on the two core-shell particles indicate that the influence of p-NIPAm is somewhat greater when it is localized in the shell.
引用
收藏
页码:8301 / 8306
页数:6
相关论文
共 45 条
  • [1] Poly(N-isopropylacrylamide) soluble polymer supports in catalysis and synthesis
    Bergbreiter, DE
    Case, BL
    Liu, YS
    Caraway, JW
    [J]. MACROMOLECULES, 1998, 31 (18) : 6053 - 6062
  • [2] HYDROGELS FOR SITE-SPECIFIC DRUG DELIVERY TO THE COLON - INVITRO AND INVIVO DEGRADATION
    BRONDSTED, H
    KOPECEK, J
    [J]. PHARMACEUTICAL RESEARCH, 1992, 9 (12) : 1540 - 1545
  • [3] Thermoresponsive photonic crystals
    Debord, JD
    Lyon, LA
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2000, 104 (27) : 6327 - 6331
  • [4] Preparation and swelling properties of poly(NIPAM) "minigel" particles prepared by inverse suspension polymerization
    Dowding, PJ
    Vincent, B
    Williams, E
    [J]. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2000, 221 (02) : 268 - 272
  • [5] Cationic amino-containing N-isopropylacrylamide-styrene copolymer latex particles: 1 - Particle size and morphology vs. polymerization process
    Duracher, D
    Sauzedde, F
    Elaissari, A
    Perrin, A
    Pichot, C
    [J]. COLLOID AND POLYMER SCIENCE, 1998, 276 (03) : 219 - 231
  • [6] Cationic amino-containing N-isopropyl-acrylamide-styrene copolymer particles: 2-surface and colloidal characteristics
    Duracher, D
    Sauzedde, F
    Elaissari, A
    Pichot, C
    Nabzar, L
    [J]. COLLOID AND POLYMER SCIENCE, 1998, 276 (10) : 920 - 929
  • [7] Motion of microgel particles under an external electric field
    Fernández-Nieves, A
    Fernández-Barbero, A
    de las Nieves, FJ
    Vincent, B
    [J]. JOURNAL OF PHYSICS-CONDENSED MATTER, 2000, 12 (15) : 3605 - 3614
  • [8] Charge controlled swelling of microgel particles
    Fernández-Nieves, A
    Fernández-Barbero, A
    Vincent, B
    de las Nieves, FJ
    [J]. MACROMOLECULES, 2000, 33 (06) : 2114 - 2118
  • [9] Guillermo A, 2000, J POLYM SCI POL PHYS, V38, P889, DOI 10.1002/(SICI)1099-0488(20000315)38:6<889::AID-POLB9>3.0.CO
  • [10] 2-L