Dr. Syed Arshad Hussain Wellcomes You


Recent paper from our lab @ Journal of Luminescence

J-aggregates of thiacyanine dye organized in LB films: Effect of irradiation of light

Syed Arshad Hussain E-mail The Corresponding Author, Dibyendu Dey, S.next term Chakraborty  and D. Bhattacharjee

Journal of Luminescence

Volume 131, Issue 8, August 2011, Pages 1655-1660

Abstract

In the present communication we report the preparation and characterizations of Langmuir and Langmuir–Blodgett films of a thiacyanine dye N,N′-dioctadecyl thiacyanineperchlorate (NK) mixed with Octadecyl trimethyl ammonium bromide (OTAB). The relationship between the molar ratio of OTAB and NK and the orientation of molecules at the air–water interface was investigated using surface pressure-area per molecule (π–A) isotherm. UV–vis absorption and fluorescence spectroscopic investigations reveal that prominent J-aggregation of NK molecule was observed in the LB films lifted at higher surface pressure. This J-aggregation can be controlled by diluting the NK molecules with OTAB. It was observed that the J-aggregates of NK decayed to monomer and H-aggregates when the NK-LB film was exposed to a monochromatic light of wavelength 460 nm (λmax of J-aggregates).

Highlights

► Langmuir and Langmuir–Blodgett films of a thiacyanine dye (NK). ► Formation of J-aggregation of NK molecule at higher surface pressures. ► Control of J-aggregates by mixing octadecyl trimethyl ammonium bromide. ► Irradiation of monochromatic light. ► J-aggregates of NK decayed to monomer and H-dimer.

Keywords: Langmuir–Blodgett; π-A isotherm; J-aggregate; Irradiation of light

View at publishers website

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New paper @ Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
July 13, 2011, 1:03 pm
Filed under: Lab News, Laboratory news, Langmuir-Blodgett Films, Publications, Student

Adsorption kinetics of a fluorescent dye in a long chain fatty acid matrix
Syed Arshad Hussain, Soma Banik, S. Chakraborty and D. Bhattacharjee
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Volume 79, Issue 5, September 2011, Pages 1642-1647

Abstract

This work reports the adsorption kinetics of a highly fluorescent laser dye rhodamine B (RhB) in a preformed stearic acid (SA) Langmuir monolayer. The reaction kinetics was studied by surface pressure–time (πt) curve at constant area and in situ fluorescence imaging microscopy (FIM). Increase in surface pressure (at constant area) with time as well as increase in surface coverage of monolayer film at air–water interface provide direct evidence for the interaction. ATR–FTIR spectra also supported the interaction and consequent complexation in the complex films. UV–vis absorption and Fluorescence spectra of the complex Langmuir–Blodgett (LB) films confirm the presence of RhB molecules in the complex films transferred onto solid substrates. The outcome of this work clearly shows successful incorporation of RhB molecules into SA matrix without changing the photophysical characteristics of the dye, thus making the dye material as LB compatible.



		
		


Highlights

► Formation of stearic acid (SA) Langmuir monolayer at air–water interface. ► Injection of fluorescent laser dye rhodamine B (RhB) from the backside of the barrier. ► Monitoring the reaction kinetics by measuring surface pressure–time (πt) curve and in situ fluorescence imaging microscopy (FIM). ► Increase in surface pressure and surface coverage of monolayer film confirm adsorption of RhB onto SA monolayer. ► ATR–FTIR and UV–vis absorption spectra of RhB–SA LB film support the adsorption.

Keywords: Langmuir monolayer; Pressure–area isotherm; Reaction kinetics; FIM; Rhodamine

View at publishers website


My recent publications

1. Langmuir-Blodgett monolayers of cationic dyes in the presence and absence of clay mineral layers: N,N’ -dioctadecyl thiacyanine, octadecyl rhodamine B and laponite.”
Syed Arshad Hussain, R. A. Schoonheydt
Langmuir (2010) [article in press]

2. Effect of nano-clay platelets on the J-aggregation of thiacyanine dye organized in Langmuir-Blodgett films
D. Bhattacharjee, Syed Arshad Hussain, S. Chakraborty, and R. A. Schoonheydt
Spectrochimica Acta Part A (2010) [article in press]

3. Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir–Blodgett (LB) films
Syed Arshad Hussain, S. Chakraborty, D. Bhattacharjee, R.A. Schoonheydt
Spectrochimica Acta Part A 75 (2010) 664–670

4. Reaction kinetics of organo-clay hybrid films: In-situ IRRAS, FIM and AFM studies
Syed Arshad Hussain, Md N. Islam, D. Bhattacharjee
Journal of Physics and Chemistry of Solids 71 (2010) 323–328

5. Photophysical studies of xanthene dye in alkanols and in inorganic ions
B Ganguly, R K Nath, S A Hussain and A K Panda
Indian J. Phys. 84 (6), 549-555 (2010)

6. Investigations of RhB18 langmuir monolayer by fluorescence imaging microscopy
S A Hussain, S Chakraborty and D Bhattacharjee
Indian J. Phys. 84 (6), 625-629 (2010)



Our new paper on Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Paper title: Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir–Blodgett (LB) films
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Volume 75, Issue 2, February 2010, Pages 664-670

Full text link of the article



Our recent paper on Journal of Physics and Chemistry of Solids
January 17, 2010, 3:51 pm
Filed under: Langmuir-Blodgett Films, Uncategorized

Title: Reaction-kinetics of organo-clay hybrid films: in-situ IRRAS, FIM and AFM studies

Keywords: A. Interface; A. Thin films; A. Optical materials; D. Surface properties; D. Optical properties

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AFM image of hectorite assembled onto quartz slide by Langmuir-Blodgett Technique

 

 



Langmuir-Blodgett (LB) Films of water-soluble materials
September 11, 2007, 8:57 am
Filed under: Langmuir-Blodgett Films, Water-soluble materials

 

Ideal LB compatible material is amphiphilic molecules having a hydrophilic (water loving) head group and a hydrophobic (water hating) tale part. Due to this amphiphatic balance these types of materials float onto water.

 

However recent observation reveal that good quality LB films can be prepared using water soluble materials. Recently we prepare the LB films of water soluble CTAB. First of all a model monolayer of a suitable amphiphilic molecule was prepared on the air-water interface. Then the solution of the sample molecule was spread from the back side of tha barrier. The water-soluble sample molecules come into the contact of the molecules of the model monolayer and interacted and forms complex. Thus a complex Langmuir monolayer of water soluble material is formed. Once this complex Langmuir monolayer is formed then it is easy to form mono- and multilayer LB films of this complex monolayer (Journal of Colloid and Interface Science 311(2) (2007) 361-367).