Concentrated natural dye extracted from turmeric spice and its use for textile dyeing

On a textile market where the rules move to the restriction of some synthetic dyes, the industrialists become interested by natural ones which are considered to be harmless. In addition, they constitute a new source of income since they allow the creation of a new market and they aim a specific group of consumers. During last few decades, increasing attention has been paid to natural dye application as food colourant, in cosmetics and in textile coloration. This work aims the extraction of a concentrated dye from turmeric spice and its application for textile dyeing. The extraction method using Soxhlet extractor yields a highly concentrated dye. The various parameters that may affect the dyeing process were investigated. It was found that pH and temperature of dyeing influence considerably the results. Quality control of all dyeing was performed using standard fastness tests and colour measurements. The results were promising for turmeric concentrated extract as a natural dye. Thermodynamics of dyeing process were investigated

2,2-Bis(3-chloro­methyl-4-ethoxy­phen­yl)propane

The title compound, C21H26Cl2O2, a bis-chloro­methyl derivative of O-ethyl­ated bis­phenol A, exhibits C 2 mol­ecular symmetry. It shows a bent conformation with the two benzene rings nearly perpendicular [dihedral angle = 87.17 (6)°]

From PEF to PBF: what difference does the longer alkyl chain make a computational spectroscopy study of poly (butylene 2,5-furandicarboxylate)

This work explores the conformational preferences and the structureproperty correlations of poly(butylene 2,5-furandicarboxylate) (PBF), a longer chain analogue of the most well-known biobased polyester from the furan family, poly(ethylene 2,5-furandicarboxylate) (PEF). A thorough computational spectroscopic study–including infrared, Raman and inelastic neutron scattering spectroscopy, combined with discrete and periodic density functional theory calculations–allowed the identification of dominant structural motifs in the amorphous and crystalline regions. Discrete calculations and vibrational spectroscopy of semi-crystalline and amorphous samples strongly support the predominance of gauche, trans, gauche conformations of the butylene glycol fragment in both the crystalline and amorphous domains. In what concerns the furandicarboxylate fragment, amorphous domains are dominated by syn,syn conformations, while in the crystalline domains the anti,anti forms prevail. A possible crystalline structure–built from these conformational preferences and including a network of C-H···O hydrogen bond contacts—was optimized using periodic density functional theory. This proposed crystal structure avoids the unrealistic structural features of the previously proposed X-ray structure, provides an excellent description of the inelastic neutron scattering spectrum of the semi-crystalline form, and allows the correlation between microscopic structure and macroscopic properties of the polymer.publishe

Application de la catalyse par transfert de phase a la synthese de nouveaux polyethers et polycarbonates par polycondensation

SIGLECNRS T 58796 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Isosorbide-based microcapsules for cosmeto-textiles

International audienc

Synthèse et étude des propriétés opto-électroniques de nouveaux polymères semi-conducteurs à chromophores séparés de type para-phénylènevinylène

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

3,3′-Bis(chloromethyl)-4,4′-diethoxy-1,1′-biphenyl

The asymmetric unit of the title compound, C18H20Cl2O2, consists of a half-molecule, the other half being generated by an inversion center, located at the mid-point of the benzene–benzene bond. Except for the two Cl atoms, all other atoms of the compound are nearly coplanar, with the atomic displacements from the molecular mean plane ranging from 0.0037 (19) to 0.071 (2) Å. The two Cl atoms are in trans positions and are displaced with respect to the mean plane by 1.687 (2) and −1.693 (3) Å. The crystal packing is governed by van der Waals interactions

Optical and electrical properties of bi-layers organic devices

The influence of interfacial charges on the device characteristics of bi-layers structure LEDs with poly[5-methoxy-2-octyloxy-1,4-phenylenevinylene] (MO-PPV) as active polymer layer is investigated. The concept to improve device performance is presented using: a diacetate cellulose (DAC) and a new synthetized 5-{2-(2-chloroethoxy)ethoxy}-2-{(E)-(2-pyridyl)azo}phenol (PDEG) components. The DAC and mixed (DAC+PDEG) layers were inserted between indium tin oxide (ITO) and MO-PPV polymer. The optical properties (UV-Vis) of MO-PPV, PDEG and mixed (DAC+PDEG) in solutions were studied and compared to those on thin films. Detailed current-voltage measurements of the bi-layers devices showed improvements of the threshold voltage (Vth) of the ITO/(DAC+PDEG)/MO-PPV/Al device attributed to the enhancement of carriers injection and transport resulted from the modified electrode structures. Conduction mechanisms of structure LEDs were matched with space-charge-limited current (SCLC) one. The impedance spectra for all devices can be discussed in terms of an equivalent circuit model designed as a parallel resistor Rp and capacitor Cp network in series with resistor Rs. The ITO/(DAC+PDEG)/MO-PPV/Al device showed the lowest impedance attributed to the removal of contaminants and to changes in the work function of ITO. The frequency-dependent electrical properties of the ITO/(DAC+PDEG)/MO-PPV/Al structure is analyzed by impedance spectroscopy as function of bias. We have extracted numerical values of the equivalent circuit model parameters by fitting experimental data. Their evolution with bias voltages has shown that the SCLC mechanism is characterized by an exponential trap distribution

Green Chemistry and Molecularly Imprinted Membranes

Technological progress has made chemistry assume a role of primary importance in our daily life. However, the worsening of the level of environmental pollution is increasingly leading to the realization of more eco-friendly chemical processes due to the advent of green chemistry. The challenge of green chemistry is to produce more and better while consuming and rejecting less. It represents a profitable approach to address environmental problems and the new demands of industrial competitiveness. The concept of green chemistry finds application in several material syntheses such as organic, inorganic, and coordination materials and nanomaterials. One of the different goals pursued in the field of materials science is the application of GC for producing sustainable green polymers and membranes. In this context, extremely relevant is the application of green chemistry in the production of imprinted materials by means of its combination with molecular imprinting technology. Referring to this issue, in the present review, the application of the concept of green chemistry in the production of polymeric materials is discussed. In addition, the principles of green molecular imprinting as well as their application in developing greenificated, imprinted polymers and membranes are presented. In particular, green actions (e.g., the use of harmless chemicals, natural polymers, ultrasound-assisted synthesis and extraction, supercritical CO2, etc.) characterizing the imprinting and the post-imprinting process for producing green molecularly imprinted membranes are highlighted