TY - JOUR
T1 - Controlled synthesis of responsive hydrogel nanostructures via microcontact printing and ATRP
AU - Chirra, Hariharasudhan D.
AU - Biswal, Dipti
AU - Hilt, J. Zach
PY - 2011/6
Y1 - 2011/6
N2 - Surfaces that are spatially functionalized with intelligent hydrogels, especially at the micro- and nanoscale, are of high interest in the diagnostic and therapeutic fields. Conventional methods of the semiconductor industry have been successfully employed for the patterning of hydrogels for various applications, but methods for fabricating precise 3 D patterns of hydrogels at the micro- and nanoscale over material surfaces remain limited. Herein, microcontact printing (μCP) followed by atom transfer radical polymerization (ATRP) was applied as a platform to synthesize temperature responsive poly(N-isopropylacrylamide) hydrogels with varied network structures (e.g. different molecular weight crosslinkers) over gold surfaces. The XY control of the hydrogels was achieved using μCP, and the Z (thickness) control was achieved using ATRP. The controlled growth and the responsive behavior of hydrogels to temperature stimuli were characterized using Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM). The results demonstrate that this platform allows for the controlled growth of hydrogel nanostructures using the controlled ATRP mechanism. It is also shown that the molecular weight of the crosslinker affects the rate of hydrogel growth. These PNIPAAm-based crosslinked hydrogel patterns were also demonstrated to have a temperature-dependent swelling response. Using this technique, it is possible to synthesize responsive hydrogel patterns over various surfaces for potential applications in the biomedical field.
AB - Surfaces that are spatially functionalized with intelligent hydrogels, especially at the micro- and nanoscale, are of high interest in the diagnostic and therapeutic fields. Conventional methods of the semiconductor industry have been successfully employed for the patterning of hydrogels for various applications, but methods for fabricating precise 3 D patterns of hydrogels at the micro- and nanoscale over material surfaces remain limited. Herein, microcontact printing (μCP) followed by atom transfer radical polymerization (ATRP) was applied as a platform to synthesize temperature responsive poly(N-isopropylacrylamide) hydrogels with varied network structures (e.g. different molecular weight crosslinkers) over gold surfaces. The XY control of the hydrogels was achieved using μCP, and the Z (thickness) control was achieved using ATRP. The controlled growth and the responsive behavior of hydrogels to temperature stimuli were characterized using Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM). The results demonstrate that this platform allows for the controlled growth of hydrogel nanostructures using the controlled ATRP mechanism. It is also shown that the molecular weight of the crosslinker affects the rate of hydrogel growth. These PNIPAAm-based crosslinked hydrogel patterns were also demonstrated to have a temperature-dependent swelling response. Using this technique, it is possible to synthesize responsive hydrogel patterns over various surfaces for potential applications in the biomedical field.
KW - ATRP
KW - Hydrogels
KW - Microcontact printing
KW - NIPAAm
KW - Surface initiated polymerization
UR - http://www.scopus.com/inward/record.url?scp=79955959177&partnerID=8YFLogxK
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U2 - 10.1002/pat.1576
DO - 10.1002/pat.1576
M3 - Article
AN - SCOPUS:79955959177
SN - 1042-7147
VL - 22
SP - 773
EP - 780
JO - Polymers for Advanced Technologies
JF - Polymers for Advanced Technologies
IS - 6
ER -