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1

Self-aggregates formation of tetrachloroperylene acid esters in Langmuir and Langmuir-Blodgett films

Modlińska A., Chrzumnicka E., Martyński T.

Opto-Electronics Review

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2017

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Vol. 25, No. 4

296--302

EN

Using Langmuir and Langmuir-Blodgett techniques molecular films of chlorinated perylene derivatives, namely tetra-n-butyl-1,6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxylate (PCn for n = 1, 5, 9) have been studied. The Langmuir films of pure compounds and mixed with liquid crystalline 4-octyl-4'-cyanobiphenyl (8CB) were characterized by surface pressure-mean molecular area isotherms. An additive rule reveals miscibility of all the dyes with 8CB but shows different types of intermolecular interaction forces. The pure and mixed Langmuir films were transferred onto quartz plates and characterized spectroscopically. Absorption and fluorescence spectra were recorded for the samples in form of diluted chloroform solution, the dye with 8CB mixtures in monomolecular Langmuir-Blodgett films and in liquid crystal cells. Different tendency to aggregation of the dye with short and long alkyl chains was observed. It is shown that the dye molecule stacking and aggregation of the chlorinated perylene dyes depend on the dye concentration and are related to the torsion of the perylene core.

2

Spectral properties of naphthalimide dyes mixed with 4-heptyl-4'-cyanobiphenyl (7CB) in Langmuir-Blodgett films

Bielejewska N., Chrzumnicka E., Stolarski R., Bauman D.

Opto-Electronics Review

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2010

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Vol. 18, No. 2

197-207

EN

Langmuir-Blodgett (LB) films formed of some fluorescent dyes, namely derivatives of 4-aminonaphthalimide, and their binary mixtures with the liquid crystal 4-heptyl-4'-cyanobiphenyl (7CB) have been studied. The electronic absorption and fluorescence spectra were recorded. On the basis of these spectra, the spectral properties of the dyes and the intermolecular interactions in ultrathin ordered films were determined. The conclusions about the tendency to the creation of aggregates by dye molecules in LB films have been drawn. The measurements of absorption by using linearly polarised light have allowed us to determine the arrangement of the dye and liquid crystal molecules on the air-solid substrate interface.

3

Molecular organization and aggregation in Langmuir and Langmuir-Blodgett films of azo dye/liquid crystal mixtures

Inglot K., Martyński T., Bauman D.

Opto-Electronics Review

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2009

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Vol. 17, No. 2

120-128

EN

A study of azo dye/liquid crystal mixtures in monolayers formed at air-water (Langmuir films) and air-solid substrate (Langmuir-Blodgett films) interfaces was performed. Three azo dyes with various molecular structure and two liquid crystal materials: 4-octyl-4'-cyanobiphenyl (8CB) and trans-4-octyl(4'-cyanophenyl)-cyclohexane (8PCH) were used. The morphology of Langmuir films was monitored by means of a Brewster angle microscope (BAM). Moreover, a surface pressure and electronic absorption spectra of the monolayer spread on the water surface of dye/liquid crystal mixtures as a function of a mean molecular area were simultaneously recorded. In addition, the absorption for Langmuir-Blodgett films deposited on quartz plates was measured. Information about intermolecular interactions in the mixtures of the nonamphiphilic dye and the liquid crystal with polar terminal group was obtained. Conclusions about the formation of self-aggregates between dye molecules have been drawn. The influence of the dye molecular structure and its concentration on aggregates' geometry was found.

4

Intermolecular interactions in Langmuir-Blodget films of liquid crystalline perylene derivatives

Hertmanowski R., Martyński T., Stolarski R., Bauman D.

Opto-Electronics Review

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2008

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Vol. 16, No. 3

237-243

EN

Langmuir-Blodgett (LB) films formed of some discotic liquid crystals, namely 3,4,9,10-tetra-(n-alkoxy-carbonyl)-perylenes, mixed with arachid acid have been studied. The absorption and fluorescence spectra were recorded. The results obtained have led to conclusions about formation of self-aggregates of dye molecules both in ground and excited states at the air-solid substrate interface. It was found that some fraction of J-aggregates can be created in the ground state. In the excited state, mostly excimers appear and the number of this kind of aggregates depends on the length of the alkyl chains substituted to the perylene core, as well as on the dye concentration and the number of layers in LB films.

5

Układy polimerowe o własnościach nieliniowo optycznych

Kucharski S., Janik R., Raźna-Kułakowska J.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2001

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Vol. 50, nr 23

35-38

PL

W referacie przedstawiono podstawowe wymagania stawiane układom polimeerowym dla uzyskania odpowiedzi o charakterze nieliniowo optycznym. Omówiono metody obliczania pierwszej hiperpolaryzowalności (b) (beta) cząteczki chromoforu metodami chemii kwantowej i jej pomiaru. Uzyskanie polimerowego materiału o właściwościach nieliniowo optycznych wymaga wbudowania chromoforu w cząsteczkę polimeru oraz jego zorientowania dla uzyskania układu o acentrosymetrycznym rozkładzie ładunku elektronowego. Omówiono to zagadnienie w oparciu o technikę filmów molekularnych Langmuira-Blodgett na przykładzie polimerów i kopolimerów akrylowych zawierających ugrupowania azobenzenowe z podstawnikami heterosulfonamidowymi w charakterze chromoforów.

EN

The fundamental requirements for polimeric systems to manifest response of the nonlinear optical (NLO) character were presented. The ways for calculation of the first hyperpolarizability b(beta) of the chromophoric molecule were described. To obtain polymeric materials showing NLO response in macro scale it is necessary to incorporate a chromophore into polymer and orient it in a way which provides acentrosymmetric discribution of electronic charge. This was realized by Langmuir-Blodgett technique applied to acrylic polymers and copolymers containing azobenzene group with heterosulfonamide substituents as chromophores.

6

Langmuir-Blodgett film formation by polymeric materials

Raźna J., Kucharski S., Bryjak M.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 10

2312-2320

EN

Polymeric materials such as: poly(n-octadecyl methacrylate), poly(n-octadecyl methacrylate-co-N-p-nitrophenylmaleimide) and poly(n-octadecyl methacrylate-co-N-p-nitrophrnylacrylamide) were synthesized to investigate their ability for monolayer film formation and deposition. It was found that polymerization of n-octadecyl methacrylateee yielded the material with improved ability of film formation as compared with the monomer, and the surface pressure-area isotherm showed a distinct solid film phase formation with a high value of film collapse pressure of ca. 56 mN/m. The incorporation of a co-monomer resulted in a shift of the surface pressure isotherm towards higher area values, still with a distinct solid film phase region and high film collapse pressure. The thickness of the poly(n-octadecyl methacrylate) film deposited onto a solid subphase was ca. 3 nm per monolayer (as determined by surface plasmon resonance) and this value corresponded to the lenght of the monomer molecule.