Interaction between dyes and polyelectrolytes, 8. Effect of polyanions on the mixed dimer formation of cationic dyes

Shirai, Masamitsu; Nagatsuka, Tatsuki; Tanaka, Makoto

doi:10.1002/macp.1978.021790117

Cited by 13 publications

(6 citation statements)

References 20 publications

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“…20,21 Furthermore, extensive work has been done looking at MB interactions with clay suspensions and polyanion solutions. [23][24][25][26][27] The chemical structure of MB is given in Figure 1. The richness of the MB absorbance spectrum also helps us understand the aggregation behavior of the dye under different conditions.…”

Section: Introductionmentioning

confidence: 99%

Methods of Loading and Releasing Low Molecular Weight Cationic Molecules in Weak Polyelectrolyte Multilayer Films

2002

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This work studied the loading capabilities and release behavior of poly(acrylic acid) (PAA) and poly-(allylamine hydrochloride) (PAH) multilayer films, using methylene blue dye (MB) as an indicator. PAA/ PAH multilayers assembled at pH ) 2.5/2.5 loaded MB throughout the multilayers due to available binding sites and a permeable structure. The amount of MB loaded increased linearly with increasing film thickness. Use of buffered MB solutions enabled faster and more uniform MB loading into the multilayers, because ions within the MB solution caused further swelling of the multilayer film. Release studies demonstrated a pH-sensitive release mechanism, where lower pH environments increased the release rate. Buffered environments also increased the release rate of MB from the multilayer films. By assembling capping layers of PAA/PAH at pH 6.5/6.5 on top of 2.5/2.5 PAA/PAH multilayers, the diffusion of MB through the multilayers was better controlled under nonbuffered conditions. Under buffered conditions, however, the permeability of the 6.5/6.5 PAA/PAH capping layers increased due to swelling, and MB diffusion was not hindered. Further work needs to be done to slow release of MB under buffered conditions. The controlled loading capabilities and pH-sensitive release behavior of weak polyelectrolyte multilayer films demonstrated here may be useful toward drug delivery applications.

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Section: Introductionmentioning

confidence: 99%

Methods of Loading and Releasing Low Molecular Weight Cationic Molecules in Weak Polyelectrolyte Multilayer Films

2002

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“…The interaction between NaPSS and dye molecules. We have examined the influence of the concentration of the polyelectrolyte on the visible spectra of AO, NR and MY according to technique reported elsewhere [1][2][3][20][21][22][23][24]. It allows determining the stoichiometry of the dye-polyelectrolyte complexes and choosing appropriate conditions for ascertainment of the apparent ionization constants.…”

Section: Resultsmentioning

confidence: 99%

“…The interactions of cationic dyes with anionic polyelectrolytes in aqueous solutions have been extensively studied [1][2][3][4]. Particularly, the metachromatic effects, the stoichiometry, and the energy of dye-polyelectrolyte interaction have been ascertained for many acid-base indicator dyes.…”

Section: Introductionmentioning

confidence: 99%

The Acid-Base Equilibrium of Cationic Dyes in the Aqueous Solutions of Poly (Sodium 4-Styrenesulfonate)

Kharchenko¹,

Moskaeva²

2016

Chemical Series

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“…Na literatura são encontrados diversos estudos envolvendo interações de corantes em sistemas micro-heterogêneos, tais como soluções contendo polieletrólitos 19,20 , ácidos nucléicos 21 , membranas lipídicas 22 , e suspensões de argilas [23][24][25][26][27][28][29][30][31][32][33][34][35] . Estes sistemas heterogêneos, agem como uma matriz de cargas que induz o ordenamento das moléculas de corante, reproduzindo interações do mesmo tipo que as observadas em soluções homogêneas mais concentradas.…”

Section: Corantes Em Meios Micro-heterogêneosunclassified

Interações entre corantes e argilas em suspensão aquosa

Neumann¹,

Gessner²,

Cione³

et al. 2000

Quím. Nova

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Recebido em 18/11/99; aceito em 16/3/00 INTERACTION BETWEEN DYES AND CLAYS IN AQUEOUS SUSPENSION.Adsorption of cationic dyes on clays can be used as a model for the interactions between organic compounds and these minerals. Cationic dyes like methylene blue are used to study these interactions because of the spectroscopic changes observed when their molecules are adsorbed on clay surfaces. Depending on the structure and layer charge of the clay particles several processes may occur, like adsorption of dye monomers and aggregates on the external and internal surfaces of the clay tactoids, migration towards internal surfaces, protonation, etc. Under certain conditions the deaggregation-aggregation of the clay particles are accelerated trapping dye species during these processes. A general scheme is proposed for the processes occurring between clays and dyes in aqueous suspensions, which can be used to explain the behaviour of specific systems.Keywords: cationic dyes; clays; clay-dye interactions. DIVULGAÇÃOAs interações de compostos orgânicos com argilas tem sido objeto de numerosas revisões da literatura 1,2 . O interesse nestes processos se direciona principalmente para o comportamento de herbicidas catiônicos 3 , fotoestabilização de complexos pesticidas-argilas 4 , moléculas de corantes orgânicos 5,6 e modificação hidrofóbica das superfícies de argilas.7 Por outro lado, as argilas podem servir como suportes e/ou catalisadores para vários tipos de reações e fotorreações. Cátions orgânicos participam de equilíbrio de troca iônica com a superfície das argilas, além de serem altamente seletivos, como mostram alguns estudos de adsorção competitiva 6 . A utilização de corantes como sondas é bastante interessante, já que são rapidamente adsorvidos pelas argilas e as diferentes espécies formadas após a adsorção são facilmente detectadas por técnicas espectroscópicas clássicas, como UV-VIS e fluorescência. A partir do conhecimento da espécie do corante formada durante o processo de adsorção, pode-se caracterizar os diferentes microambientes (sítios de adsorção) presentes em cada tipo de argilas. O conhecimento das características desses sítios tem grande importância, por exemplo, quando se deseja descrever a reatividade de algumas macromoléculas biológi-cas, como enzimas e proteínas, encontradas nos solos 8 , a ação de pesticidas e herbicidas 3,4 , e em geral todos os processos envolvendo solos. A mesma metodologia descrita, empregando corantes como sondas, é também aplicada ao uso de sistemas similares como zeolitas e silicatos 9 . ARGILAS 10-12A definição clássica designa argila como um material natural, terroso, de granulação fina que quando umedecido com água apresenta plasticidade. Os minerais constituintes das argilas são os argilominerais. Estes compostos são silicatos hidratados que possuem estrutura em camadas constituídas por folhas contínuas formadas por tetraedros de silício (ou alumí-nio) e oxigênio, e folhas formadas por octaedros de alumínio (magnésio ou ferro) e oxigênio e hidroxilas (Figura 1). 11Uma f...

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Interaction between dyes and polyelectrolytes, 8. Effect of polyanions on the mixed dimer formation of cationic dyes

Cited by 13 publications

References 20 publications

Methods of Loading and Releasing Low Molecular Weight Cationic Molecules in Weak Polyelectrolyte Multilayer Films

Methods of Loading and Releasing Low Molecular Weight Cationic Molecules in Weak Polyelectrolyte Multilayer Films

The Acid-Base Equilibrium of Cationic Dyes in the Aqueous Solutions of Poly (Sodium 4-Styrenesulfonate)

Interações entre corantes e argilas em suspensão aquosa

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