There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Nature And Properties Of Soils

Elements Of X Ray Diffraction

In recent years, natural fibers reinforced composites have received much attention because of their lightweight, nonabrasive, combustible, nontoxic, low cost and biodegradable properties. Among the various natural fibers; flax, bamboo, sisal, hemp, ramie, jute, and wood fibers are of particular interest. A lot of research work has been performed all over the world on the use of natural fibers as a reinforcing material for the preparation of various types of composites. However, lack of good interfacial adhesion, low melting point, and poor resistance towards moisture make the use of natural fiber reinforced composites less attractive. Pretreatments of the natural fiber can clean the fiber surface, chemically modify the surface, stop the moisture absorption process, and increase the surface roughness. Among the various pretreatment techniques, graft copolymerization and plasma treatment are the best methods for surface modification of natural fibers. Graft copolymers of natural fibers with vinyl monomers provide better adhesion between matrix and fiber. In the present article, the use of pretreated natural fibers in polymer matrix-based composites has been reviewed. Effect of surface modification of natural fibers on the properties of fibers and fiber reinforced polymer composites has also been discussed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Pretreatments of Natural Fibers and their Application as Reinforcing Material in Polymer Composites—A Review

In materials science, “green” synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including
 metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of “green” synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.

/pdf/green-synthesis-of-metals-and-their-oxide-nanoparticles-4onh2g0i4w.pdf

‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

Nature and natural resources has offered the mankind with precious gifts for survival and maintenance but with the ever increase in population, pollution and deforestation the sustenance of natural resources is in suspicion. A major part of the land on earth provides us with renewable biomass that mostly degrades with time. Graft copolymerization is a chemical technique to improve the properties of the waste biomass and modify its properties while sustaining the inherent trait. With the advancement of science and research many efforts have been made to modify and improve the synthesis, characterization and evaluation techniques for a better scientific and industrial achievements. The review explores a brief overview of this magnificent engineering, its types and factors that has helped to provides with outstanding results.

https://www.longdom.org/open-access/reprocessing-the-natural-fibers-to-procure-advanced-materials-2157-7048.1000122.pdf

Reprocessing the Natural Fibers to Procure Advanced Materials

In this article, the morphologic transformation of Hibiscus sabdariffa, a natural fiber through graft copolymerization with ethyl acrylate using ceric ammonium nitrate–nitric acid initiator system, has been reported. Different reaction parameters such as temperature, time, initiator concentration, monomer concentration, and pH were optimized to get maximum graft yield (117.3%). The graft copolymer thus formed was characterized by Fourier transform infrared, scanning electron micrographs, X-ray diffraction, thermogravimetric analysis, and differential thermogravimetric analysis techniques. The graft copolymer was found to be moisture, chemical, and thermal resistant. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Synthesis, characterization, and evaluation of novel Hibiscus sabdariffa-g-poly(EA) copolymer

This article deals with synthesis of phenol-formaldehyde resin and preparation of phenol-formaldehyde matrix based composites using raw flax and flax graft co-polymer as reinforcing agent. Prior to...

Analysis of Mechanical Behavior of Phenol Formaldehyde Matrix Composites Using Flax-g-Poly (MMA) as Reinforcing Materials:

Modification of natural polymers like protein by graft co-polymerization is an important method to incorporate the desired properties into the backbone. Soy protein concentrate (SPC) was grafted with ethylmethacrylate (EMA) using ascorbic acid /potassium persulphate as redox initiator system under pressure. Different reaction parameters such as reaction time, reaction pressure, solvent amount, initiator ratio, pH and monomer concentration were optimized to get maximum graft yield (59.5%). The optimized reaction conditions were: reaction time; 150 min, reaction pressure; 7.5 psi, solvent; 150ml, AAc: KPS; 1:1.25, pH; 8, [EMA]; 1.99 X 10 -3 Mol L -1 . The graft copolymer formed was characterized by FTIR, XRD and SEM techniques. The grafted protein was found to undergo physico-chemical changes on incorporation of polymer chains onto backbone through graft copolymerization which resulted in enhanced resistance towards moisture absorbance and acid-base attack. Thermal analysis showed higher final decomposition temperature of grafted protein as compared to that of ungrafted backbone.

http://ijsts.shirazu.ac.ir/article_3402_fe010c18d94357966d95409ef1956c0b.pdf

Induction of morphological changes in soy protein concentrate through pressure induced graft copolymerization and evaluation of chemical and thermal properties

Corrigendum to "Characterization and evaluation of methylmethacrylate-acetylated Saccharum spontaneum L. graft copolymers prepared under microwave'' [Carbohydr. Polym. 78/4 (November (17)) (2009) 987-996].

Balbir Singh Kaith

Papers

Reprocessing the Natural Fibers to Procure Advanced Materials

Synthesis, characterization, and evaluation of novel Hibiscus sabdariffa-g-poly(EA) copolymer

Analysis of Mechanical Behavior of Phenol Formaldehyde Matrix Composites Using Flax-g-Poly (MMA) as Reinforcing Materials:

Induction of morphological changes in soy protein concentrate through pressure induced graft copolymerization and evaluation of chemical and thermal properties

Corrigendum to "Characterization and evaluation of methylmethacrylate-acetylated Saccharum spontaneum L. graft copolymers prepared under microwave'' [Carbohydr. Polym. 78/4 (November (17)) (2009) 987-996].