Photoresponsive Wettability in Monolayer Films from Sinapinic Acid
Sinapinic acid is an interesting material because it is both antioxidant and antibacterial agent. In addition, when illuminated with ultraviolet light, it can exhibit the so-called photodimerization process. In this paper, we report on the investigation of monolayer films from 3,5-dimethoxy-4-hydrox...
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doaj-1f02097d70b5433ea4682002bc3913ea2020-11-25T02:34:34ZengHindawi LimitedThe Scientific World Journal1537-744X2013-01-01201310.1155/2013/915237915237Photoresponsive Wettability in Monolayer Films from Sinapinic AcidCleverson A. S. Moura0Douglas J. C. Gomes1Nara C. de Souza2Josmary R. Silva3Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, 78600-000 Barra do Garças, MT, BrazilGrupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, 78600-000 Barra do Garças, MT, BrazilGrupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, 78600-000 Barra do Garças, MT, BrazilGrupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, 78600-000 Barra do Garças, MT, BrazilSinapinic acid is an interesting material because it is both antioxidant and antibacterial agent. In addition, when illuminated with ultraviolet light, it can exhibit the so-called photodimerization process. In this paper, we report on the investigation of monolayer films from 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SinA) deposited onto poly(allylamine hydrochloride), PAH, films. SinA monolayers were prepared by using the layer-by-layer (LbL) self-assembly technique. Adsorption kinetics curves were well fitted by a biexponential function suggesting that the adsorption process is determined by two mechanisms: nucleation and growth of aggregates. By using wetting contact angle analysis, we have found that SinA monolayers exhibit photoresponsive wettability under UV irradiation (365 nm); that is, wettability decreases with increasing UV irradiation time. The photoresponse of wettability was attributed to photodimerization process. This hypothesis was supported by the dependence of surface morphological structure and absorption on UV irradiation time. The mechanism found in the well-known transcinnamic acid crystals is used to explain the photodimerization process in SinA monolayers.http://dx.doi.org/10.1155/2013/915237 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Cleverson A. S. Moura Douglas J. C. Gomes Nara C. de Souza Josmary R. Silva |
spellingShingle |
Cleverson A. S. Moura Douglas J. C. Gomes Nara C. de Souza Josmary R. Silva Photoresponsive Wettability in Monolayer Films from Sinapinic Acid The Scientific World Journal |
author_facet |
Cleverson A. S. Moura Douglas J. C. Gomes Nara C. de Souza Josmary R. Silva |
author_sort |
Cleverson A. S. Moura |
title |
Photoresponsive Wettability in Monolayer Films from Sinapinic Acid |
title_short |
Photoresponsive Wettability in Monolayer Films from Sinapinic Acid |
title_full |
Photoresponsive Wettability in Monolayer Films from Sinapinic Acid |
title_fullStr |
Photoresponsive Wettability in Monolayer Films from Sinapinic Acid |
title_full_unstemmed |
Photoresponsive Wettability in Monolayer Films from Sinapinic Acid |
title_sort |
photoresponsive wettability in monolayer films from sinapinic acid |
publisher |
Hindawi Limited |
series |
The Scientific World Journal |
issn |
1537-744X |
publishDate |
2013-01-01 |
description |
Sinapinic acid is an interesting material because it is both antioxidant and antibacterial agent. In addition, when illuminated with ultraviolet light, it can exhibit the so-called photodimerization process. In this paper, we report on the investigation of monolayer films from 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SinA) deposited onto poly(allylamine hydrochloride), PAH, films. SinA monolayers were prepared by using the layer-by-layer (LbL) self-assembly technique. Adsorption kinetics curves were well fitted by a biexponential function suggesting that the adsorption process is determined by two mechanisms: nucleation and growth of aggregates. By using wetting contact angle analysis, we have found that SinA monolayers exhibit photoresponsive wettability under UV irradiation (365 nm); that is, wettability decreases with increasing UV irradiation time. The photoresponse of wettability was attributed to photodimerization process. This hypothesis was supported by the dependence of surface morphological structure and absorption on UV irradiation time. The mechanism found in the well-known transcinnamic acid crystals is used to explain the photodimerization process in SinA monolayers. |
url |
http://dx.doi.org/10.1155/2013/915237 |
work_keys_str_mv |
AT cleversonasmoura photoresponsivewettabilityinmonolayerfilmsfromsinapinicacid AT douglasjcgomes photoresponsivewettabilityinmonolayerfilmsfromsinapinicacid AT naracdesouza photoresponsivewettabilityinmonolayerfilmsfromsinapinicacid AT josmaryrsilva photoresponsivewettabilityinmonolayerfilmsfromsinapinicacid |
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