PMID- 22029413
OWN - NLM
STAT- MEDLINE
DCOM- 20120404
LR  - 20141120
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 115
IP  - 49
DP  - 2011 Dec 15
TI  - Deswelling kinetics of color tunable poly(N-isopropylacrylamide) microgel-based 
      etalons.
PG  - 14359-68
LID - 10.1021/jp207138f [doi]
AB  - Poly(N-isopropylacrylamide) (pNIPAm) microgel-based etalons are optical materials 
      fabricated by depositing a monolithic layer of microgels on a semitransparent Au 
      film adhered to a glass coverslip, followed by the deposition of a second 
      semitransparent Au layer over the microgel layer (overlayer). These materials 
      exhibit characteristic colors and multipeak reflectance spectra, both of which 
      depend on the distance between the Au surfaces (mediated by the microgel 
      diameter) and the refractive index of the microgel layer. In this submission, the 
      deswelling kinetics of pNIPAm microgel-based etalons are investigated by inducing 
      microgel deswelling through exposure to a 30% methanol/H(2)O solution. Exposed to 
      this solvent system, the transition temperature of the microgels is lowered to a 
      temperature below the experimental temperature and the microgels comprising the 
      etalon collapse. This collapse induces an etalon color change, which is observed 
      as a blue shift in the reflectance spectrum. The kinetics of deswelling were 
      shown to be strongly dependent on the thickness of the Au overlayer, e.g., 
      thicker overlayers slow the solvent exchange and the resultant deswelling 
      kinetics. Additionally, for thicker overlayers, the rate of deswelling increases 
      with decreasing etalon size. Taken together, these results suggest that the 
      kinetics depend strongly on the ability of the solvent to exchange from/to the 
      microgel layer. For example, if the Au overlayer is thin, more solvent can 
      exchange through the overlayer in a given amount of time compared to an etalon 
      composed of a thick overlayer. Likewise, etalons of smaller dimensions have 
      faster deswelling kinetics due to the shorter distance the solvent needs to 
      travel laterally through the microgel layer to exchange. The results from this 
      study are of fundamental importance but will be used to develop sensors with fast 
      response times for point-of-care diagnostics.
FAU - Carter, Matthew C D
AU  - Carter MC
AD  - Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
FAU - Sorrell, Courtney D
AU  - Sorrell CD
FAU - Serpe, Michael J
AU  - Serpe MJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20111116
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
RN  - 0 (Acrylamides)
RN  - 0 (Acrylic Resins)
RN  - 0 (Gels)
RN  - 0 (Polymers)
RN  - 059QF0KO0R (Water)
RN  - 25189-55-3 (poly-N-isopropylacrylamide)
RN  - 7440-57-5 (Gold)
RN  - Y4S76JWI15 (Methanol)
SB  - IM
MH  - Acrylamides/*chemistry
MH  - Acrylic Resins
MH  - Gels/*chemistry
MH  - Gold/chemistry
MH  - Kinetics
MH  - Methanol/chemistry
MH  - Polymers/*chemistry
MH  - Temperature
MH  - Water/chemistry
EDAT- 2011/10/28 06:00
MHDA- 2012/04/05 06:00
CRDT- 2011/10/28 06:00
PHST- 2011/10/28 06:00 [entrez]
PHST- 2011/10/28 06:00 [pubmed]
PHST- 2012/04/05 06:00 [medline]
AID - 10.1021/jp207138f [doi]
PST - ppublish
SO  - J Phys Chem B. 2011 Dec 15;115(49):14359-68. doi: 10.1021/jp207138f. Epub 2011 
      Nov 16.