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rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
2006-7-6
pubmed:abstractText
We observed Fabry-Perot fringes in the absorption spectra of hydrogen-bonded layer-by-layer (LBL) films of poly(vinyl pyrrolidone) (PVPON) and poly(acrylic acid) (PAA), which stem from the interferences between beams transmitted and partially reflected at the highly smooth film-air interface and film-quartz interface. The appearance and disappearance of Fabry-Perot fringes can be used to evaluate the homogeneity of the film. They also provide information about the film thickness. Using this optical phenomenon, with a minimal requirement of instrumentation, we studied the effect of several experimental conditions on the film buildup and structure. The film grows linearly with dipping cycles. Films fabricated from higher molecular weight polymers tend to be thicker. Increasing the concentration of the assembly solutions can also make thicker films. However, films from high molecular weight polymers or high concentration assembly solutions may be heterogeneous and do not display Fabry-Perot fringes in their absorption spectra. The defects in these heterogeneous films can be healed by a postannealing in water or diluted HCl to allow the chain rearrangement to complete. We further found the PVPON/PAA films can be eroded by long-term annealing in water or diluted HCl by monitoring the movement of the Fabry-Perot fringes. In most cases, the erosion rate is constant with annealing time. The erosion rate decreases with a decrease in the pH of the media and an increase in the molecular weight of the polymers.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jul
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
110
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13484-90
pubmed:year
2006
pubmed:articleTitle
Fabry-Perot fringes and their application to study the film growth, chain rearrangement, and erosion of hydrogen-bonded PVPON/PAA films.
pubmed:affiliation
State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
pubmed:publicationType
Journal Article