NOPR Collection:

Synthesis and evaluation of novel photochromic disazo condensation pigments

2013-04-17T16:31:24Z

Title: Synthesis and evaluation of novel photochromic disazo condensation pigments Authors: Bhalakia, Samir M; Modi, Bhavin J; Patel, Ranjan G Abstract: Photochromic disazo condensation pigments have been synthesized by the condensation of 1-azaphenyl mercuric acetate-2-hydroxy-3-naphthoic acid with various benzidine derivatives and subsequent treatment with dithizone. The photochromic disazo condensation pigments have been characterized by their IR spectra and elemental analysis. The kinetic study of photochromic behaviour has been investigated by preparing films of the pigment. The pigment film on exposure to sunlight or tungsten light source of suitable wavelength showed very good photochromic effect. The film regained its original colour on removal from sunlight. The duration for return of the colour depends upon the intensity of incident light, ambient temperature, moisture content and thermal treatment of the film. Page(s): 12-18

Pure diethylamine phosphate from crude phosphoric acid

2013-04-13T16:31:13Z

Title: Pure diethylamine phosphate from crude phosphoric acid Authors: Hanna, A A; Ali, A F; Khalil, M Sh Abstract: Pure diethylamine dihydrogen phosphate was prepared from crude wet-process phosphoric acid (WPA). The prepared samples were characterized by chemical analysis, potentiometric titration, thermal analysis, and X-ray diffraction to show good purity levels comparable to those of the standard samples. The obtained results indicate that the prepared salt could be a suitable source for the phosphate value to produce pure orthophosphates of alkali metals and other important monophosphates. Page(s): 43-47

Chitosan-amine oxide: Thermal behaviour of the new gelling system

2013-04-10T16:32:01Z

Title: Chitosan-amine oxide: Thermal behaviour of the new gelling system Authors: Dutta, Pradip Kumar; Kumar, M N V Ravi Abstract: Thermal properties of chitosan and chitosan-amine oxide gel were examined. Chitosan gel was prepared from chitosan and N-methyl morpholine-N-oxide (NMMO). The modulated differential scanning calorimetry (mdsc) technique was employed to ascertain glass transition temperature (Tg) and enthalpy change (ΔH) of chitosan and gel. The chitosan and gel showed T_g values at 150 and 156°C respectively. The T_g of the gel was observed about 6°C higher than that of chitosan and the increased T_g of the gel was due to the restricted molecular movement, owing to fomation of N=O bonding at C₂position of chitosan. The thermal behaviour of chitosan and gel have confirmed by evaluation of enthalpy changes. Page(s): 55-56

Preparation and characterisation of activated carbon from agricultural wastes

2013-04-12T16:31:19Z

Title: Preparation and characterisation of activated carbon from agricultural wastes Authors: Rengaraj, S; Arabindoo, Banumathi; Murugesan, V Abstract: Solid waste disposal has become a major problem in India. Either it has to be disposed safely or used for the recovery of valuable materials. As agricultural wastes like myrobalan, rubber seed coat, cashewnut sheath, palm seed coal, palm tree flower and pongam seed coat comprise of cellulose and lignin, they may act as good adsorbents. Therefore these wastes have been exploited for the preparation of activated carbon employing various techniques. Their characterisation studies such as bulk density, moisture content, ash content, fixed carbon content, matter soluble in water, matter soluble in acid, pH, decolourising power, phenol number, ion exchange capacity, iron content and surface area have been carried out to assess the suitability of these carbons as adsorbents in the treatment of water and wastewater. The results obtained show them to be good adsorbents for both organics and inorganics. The present study reveals the recovery of valuable adsorbents from readily and cheaply available agricultural wastes. Page(s): 1-4