National Chemical Laboratory

About: National Chemical Laboratory is a facility organization based out in Pune, Maharashtra, India. It is known for research contribution in the topics: Catalysis & Nanoparticle. The organization has 8891 authors who have published 14837 publications receiving 387600 citations.

Modeling of noncatalytic gas-solid reactions

Abstract: This paper presents a critical review of the developments in the mathematical modeling of gas-solid noncatalytic reactions with particular emphasis on recent trends in the subject. A number of models proposed for analyzing this class of reactions have been reviewed with a fairly detailed discussion of the methods of incorporating structural changes which occur in the solid with the progress of reaction. The present status on the modeling of various types of complex gas-solid reactions is reviewed. Also the paper points out a number of areas in which future research may be needed. The review concludes with a critical discussion on the type of experimental data necessary for model verification and some comments on the choice of model for a given system.

Fruit peel waste: characterization and its potential uses

Abstract: Globally, India is the leading producer of fruits. Fruits after consumption leave a peel which is a nuisance to the environment as a solid waste. In this article, commonly available large volume-fruit peels (FP) (viz. banana, orange, citrus, lemon and jackfruit) were investigated for surface, physical and chemical characteristics with a view to propose their valorization in detail. Each FP was characterized by proximate and ultimate analysis, porosity, particle density, bulk density, point of zero charge (pH pzc ), surface pH, surface charges, water absorption capacity, BET surface area, scanning electron microscopy, Fourier transform infrared spectroscopy and TGA/derivative of thermogravimetric. The BET surface area of FP is very less, between 0.60 and 1.2 m 2 /g. The pH pzc and surface pH values of orange peel (OP), citrus peel (CP), lemon peel (LP) and jackfruit peels (JFP) are in the range of 3-4. The pH pzc value and surface pH of banana peel (BP) is closer to 7. The order of surface acidity is OP > LP > CP > JFP > BP. From TG curves it is clear that FPs are stable below 150°C. The results will be useful for rational design, when FP is used as a substrate for bioactive compounds, phenolic antioxidants, organic acids, enzymes, biofertilizer, production of energy and as adsorbents.

Ultrastable Imine-Based Covalent Organic Frameworks for Sulfuric Acid Recovery: An Effect of Interlayer Hydrogen Bonding.

Abstract: Covalent Organic Frameworks (COFs) have convened inordinate scientific attention from last few years because of their unique tunable porosity and long range ordered structures with high atomic precisions. Although the high crystalline nature with considerable porosity fashioned these novel materials as an eligible candidate for diverse applications, the ordered nano-channels with controllable pore aperture, especially regarding membrane separations in extreme conditions, have been poorly explored. Herein, we have demonstrated rapid and scalable synthesis of six new imine-linked highly crystalline and porous COFs via salt (p-toluenesulfonic acid) mediated solid state crystallization approach. These as-synthesized materials show exceptionally high chemical stability in harsh environments including conc. H2SO4 (36 N), conc. HCl (12 N) and NaOH (9N). This is exclusivly because of the presence of strong interlayer C–H***N H-bonding interactions among the individual layers. This H-bonding reinforce interlayer stacking interaction and provides a steric hindrance and hydrophobic environ-ment around the imine (–C=N) bonds making it safe from hydrolysis, as confirmed by Density Functional Theory (DFT) calculations. By taking advantage of processability of COF powders in salt mediated synthesis approach, the continuous, porous, crystalline, self-standing and crack-free COF membranes (COFMs) with high chemical stability have been transmut-ed, for their potential applications to separate various environmentally toxic materials from drinking water with high water flux. Moreover, owing to its highly robust backbone, the COFM have showed unprecedented Sulfuric acid (12 N) permeance reflecting its potential applications for sulfuric acid purification. Also, the as-synthesized COFMs exhibit exceptionally high permeance of acetonitrile (380 Lm-2h-1bar-1) and acetone (340 Lm-2h-1bar-1).