Morphological Structure Characterization of PAH/NiTsPc Multilayer Nanostructured Films

Silva, Josmary R.; Brito, Jackeline B.; Tanimoto, Sonia T.; Souza, Nara C. de

doi:10.4236/msa.2011.211221

Cited by 3 publications

(4 citation statements)

References 40 publications

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“…According to X-ray data [11,12] the distance between π-π-interacting molecules is no more than 3 -4 A. π-πdimers of hydroxoaluminium tetraantraquinoporphyrazines can't form complexes with pyridine because of axial OH-groups on the outer side of dimer and too small internal space. Consequently the equilibrium:…”

Section: Resultsmentioning

confidence: 99%

Thermodynamical Approach for Choosing the Carrier System for Tetraantraquinoporphyrazines

Lebedevа¹,

Mal’kova²,

Gubarev³

et al. 2013

IJOC

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On the example of tetraantraquinoporphyrazines-potential photosensitizers for photodynamic therapy, thermodynamic approach to the choice of exogenous transport system was demonstrated. By means of isothermal titration calorimetry and electron absorption spectroscopy, the state of TAP in aqueous solutions was studied. The possibility of aggregation equilibrium displacement due to the pyridine adding was evaluated.

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Section: Resultsmentioning

confidence: 99%

Thermodynamical Approach for Choosing the Carrier System for Tetraantraquinoporphyrazines

Lebedevа¹,

Mal’kova²,

Gubarev³

et al. 2013

IJOC

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“…During this process, the exposition of tryptophans to solvent would decrease with increasing aggregate sizes leading to a decrease in absorbance. The process of diffusion-limited aggregation can play an important role in the formation of the fractal structures observed in this work [5]. …”

Section: Resultsmentioning

confidence: 99%

“…LbL technique is based on adsorption process which can be understood by analyzing the adsorption kinetics (study of layer growth over time) and adsorption isotherms (study of adsorbed amount versus concentration). In addition, morphological analysis may also reveal information about the interaction between molecules [5]. …”

Section: Introductionmentioning

confidence: 99%

Ascorbic Acid and BSA Protein in Solution and Films: Interaction and Surface Morphological Structure

Maciel

Almeida²,

Godinho³

et al. 2013

BioMed Research International

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This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, K, determined for aggregates from BSA and AA was found to be about 102 M−1, which indicated low affinity of AA with BSA. For the BSA/AA films, it was also noted that the AA adsorption process and surface morphological structures depended on AA concentration. By changing the contact time between the AA and BSA, a hypochromism was revealed, which was associated to decrease of accessibility of solvent to tryptophan due to formation of aggregates. Furthermore, different morphological structures of aggregates were observed, which were attributed to the diffusion-limited aggregation. Since most of studies of interactions of drugs and proteins are performed in solution, the analysis of these processes by using films can be very valuable because this kind of system is able to employ several techniques of investigation in solid state.

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“…In this work, nanostructured ultrathin films are formed based on the LBL technique by physical adsorption, based on the van der Waals interactions and electrostatic interactions between the polyelectrolytes of opposite charges. Computational simulations were performed using molecular dynamics (MD) [6][7][8] to increase the knowledge about the metal tetrasulfonated phthalocyanine (MTsPc) [9][10][11][12][13][14][15] and poly(amidoamine) (PAMAM)dendrimers [16][17][18][19][20][21][22][23][24] in the deposition process, respectively, on poly(allylamine hydrochloride) (PAH)polymers [25] and on the film formed by MTsPc with PAH (MTsPc-PAH).…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics of Film Formation of Metal Tetrasulfonated Phthalocyanine and Poly Amidoamine Dendrimers

Silva

Neto

Gaffo

et al. 2013

Journal of Nanomaterials

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We performed molecular dynamics computer simulations to elucidate the behavior and properties of the metal tetrasulfonated phthalocyanine molecule and the poly(amidoamine) dendrimers in self-assembly depositions, respectively, on poly(allylamine hydrochloride) polymer and on film formed by metal tetrasulfonated phthalocyanine with poly(allylamine hydrochloride). Important physical properties of phthalocyanines were obtained such as the kinetic energy and temperaturein situ. By the semiempirical model, we also obtained the UV-Vis absorption spectrum of the film formed by cobalt tetrasulfonated phthalocyanine deposited on poly(allylamine hydrochloride). We performed a study with poly(amidoamine) dendrimers on their deposition time on metal tetrasulfonated phthalocyanine, poly(allylamine hydrochloride) film, and we show the relationship of deposition time with the electrical charge and molecular mass of phthalocyanines. The deposition times of the dendrimers, as a function of their mass, were also elucidated.

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Morphological Structure Characterization of PAH/NiTsPc Multilayer Nanostructured Films

Abstract: ABSTRACT

Cited by 3 publications

References 40 publications

Thermodynamical Approach for Choosing the Carrier System for Tetraantraquinoporphyrazines

Thermodynamical Approach for Choosing the Carrier System for Tetraantraquinoporphyrazines

Ascorbic Acid and BSA Protein in Solution and Films: Interaction and Surface Morphological Structure

Molecular Dynamics of Film Formation of Metal Tetrasulfonated Phthalocyanine and Poly Amidoamine Dendrimers

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