Spectral, dyeing and antimicrobial properties of some monoazo naphthalimide dyes on polyamide

A series of monoazo disperse dyes based on naphthalimide has been applied on to the nylon fabrics. The build-up values and dyeing properties of these dyes, such as leveling, and wash, light and rub fastnesses on nylon fabrics have been assessed. The dyes N-2-aminomethylpyridine-1,8-naphthalimide- azo-4″-N,N-diethyl meta toluidine (A) and N-2-aminomethylpyridine-1,8-naphthalimide-azo-2″- acetylamino-4″- N,N- diethyl aniline (B) show higher build-up values on polyamide fabrics as compared to the dyes N-2-aminomethylpyridine-1,8-naphthalimide- azo- 4″- N-hydroxy ethyl-N- ethyl aniline (C) and N-2-aminomethylpyridine-1,8-naphthalimide- azo- 4″- N-hydroxy ethyl-N- ethyl aniline quaternized with 1- bromobutane (D). All of the applied dyes exhibit excellent rub fastness, good wash fastness and moderate light fastness on nylon fabrics. In addition, the molar extinction coefficient, wavelengths of the maximum absorption and solvatochromism effects have also been studied using chloroform, toluene, and DMF as solvents. Positive solvatochromism occurs when toluene is replaced by DMF as solvent. The antimicrobial properties of dyed fabrics are evaluated against various bacteria; the dyed fabrics exhibit antimicrobial efficacy against both Gram-positive and Gram-negative bacteria.

Synthesis and Evaluation of Photovoltaic Properties of an Organic Dye for Dye-Sensitized Solar Cells

In the present study, metal free organic dyes were prepared and used as photo-sensitizers in dye-sensitized solar cells. Double rhodanine was utilized as the fundamental electron acceptor group to which electron donor aldehyde with varying substituents was attached to produce new organic dye. This dye was first purified and then characterized by analytical techniques. Spectrophotometric evaluations of the prepared dye in solution and on a nano anatase TiO2 substrate were carried out in order to assess possible changes in the status of the dyes in different environments. The results show that the dye form j-type aggregates on the nano TiO2. Additionally, oxidation potential measurements were also carried out. Finally, dye sensitized solar cell based on synthesized dye was fabricated in order to determine the photovoltaic behavior and conversion efficiency of individual dye

Investigation of Green Dye-Sensitized Solar Cells Based on Natural Dyes

Natural dyes, extracted from black carrot and bramble, were utilized as photosensitizers to prepare dye-sensitized solar cells (DSSCs). Spectrophotometric studies of the natural dyes in solution and on a titanium dioxide substrate were carried out in order to assess changes in the status of the dyes. The results show that the bathochromic shift is seen on the photo-electrode substrate. The chemical binding of the natural dyes at the surface photo-electrode were increased by the chelating effect of the Ti(IV) ions. The cyclic voltammetry results showed that all extracts are suitable to be performed in DSSCs. Finally, photochemical performance and stability of DSSCs based on natural dyes were studied. The DSSCs sensitized by black carrot extract have been reported to achieve up to Jsc=1.17 mAcm-2, Voc= 0.55 V, FF= 0.52, η=0.34%, whereas Bramble extract can obtain up to Jsc=2.24 mAcm-2, Voc= 0.54 V, FF= 0.57, η=0.71%. The power conversion efficiency was obtained from the mixed dyes in DSSCs. The power conversion efficiency of dye-sensitized solar cells using mixed Black carrot and Bramble dye is the average of the their efficiency in single DSSCs

Spectral, dyeing and antimicrobial properties of some monoazo naphthalimide dyes on polyamide

425-430A series of monoazo disperse dyes based on naphthalimide has been applied on to the nylon fabrics. The build-up values and dyeing properties of these dyes, such as leveling, and wash, light and rub fastnesses on nylon fabrics have been assessed. The dyes N-2-aminomethylpyridine-1,8-naphthalimide- azo-4″-N,N-diethyl meta toluidine (A) and N-2-aminomethylpyridine-1,8-naphthalimide-azo-2″- acetylamino-4″- N,N- diethyl aniline (B) show higher build-up values on polyamide fabrics as compared to the dyes N-2-aminomethylpyridine-1,8-naphthalimide- azo- 4″- N-hydroxy ethyl-N- ethyl aniline (C) and N-2-aminomethylpyridine-1,8-naphthalimide- azo- 4″- N-hydroxy ethyl-N- ethyl aniline quaternized with 1- bromobutane (D). All of the applied dyes exhibit excellent rub fastness, good wash fastness and moderate light fastness on nylon fabrics. In addition, the molar extinction coefficient, wavelengths of the maximum absorption and solvatochromism effects have also been studied using chloroform, toluene, and DMF as solvents. Positive solvatochromism occurs when toluene is replaced by DMF as solvent. The antimicrobial properties of dyed fabrics are evaluated against various bacteria; the dyed fabrics exhibit antimicrobial efficacy against both Gram-positive and Gram-negative bacteria

Reactive dye removal from wastewater using a chitosan nanodispersion

Adsorption of an azo reactive dye, C.I. Reactive Red 120 (RR120), from aqueous solution on chitosan and on a chitosan nanodispersion has been studied. The nanodispersion was prepared using a mixture of chitosan and sodium tripolyphosphate. The results showed that the adsorption of RR120 on dissolved chitosan and on the chitosan nanodispersion was affected significantly by initial dye concentration, sorbent amount, temperature, pH and ionic strength of the solution. Maximum dye removal for both adsorbents was at a pH of 4-5 and the adsorption of the reactive dye on both dissolved chitosan and the nanodispersion gave good fit to the Langmuir isotherm model. The adsorption capacity of the nanodispersion was around 910mgg-1, much higher than of dissolved chitosan, which was 51mgg-1. The adsorption of the dye on the chitosan nanodispersion reached equilibrium much faster than on dissolved chitosan. The kinetics of the adsorption correlated well with the pseudo-second order model