scholarly journals NATURAL POLYMER GRAFTED WITH SYNTETHIC MONOMER BY MICROWAVE FOR WATER TREATMENT - A REVIEW

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Efrén de Jesús Muñoz Prieto ◽  
Bernabé Rivas ◽  
Julio Sánchez
Keyword(s):  
Water Treatment ◽  
Microwave Heating ◽  
Spectroscopic Analysis ◽  
Graft Copolymers ◽  
Analytical Techniques ◽  
Natural Polymer ◽  
Natural Polymers ◽  
Synthesis Mechanism ◽  
Microwave Assisted

<strong>Abstract</strong><span>In this study, the use of natural polymers grafted with synthetic monomers to obtain copolymers for specific applications is revised. This review highlights current uses of microwave heating, in the grafting modifications of naturalpolymers, with other synthetic monomers and explores methodology of this technique. Microwave assisted and microwave initiated synthesized graft copolymers show superior flocculation characteristics when compared with graft copolymers produced by conventional methods. Synthesis,mechanism and characterization of these materials by different analytical techniques such as spectroscopic analysis and others are reviewed. We explore information concerning the development and characterization of grafting polymers, which have been receiving enlarged attention in recentyears as flocculants for water treatment. The effectiveness of flocculation for applications in reduction of pollutants in wastewater is also evaluated. </span><br /><strong>Keywords: </strong><span>Copolymer, Flocculant, Grafting, Microwave, Wastewater</span>

scholarly journals Modification of PLA-Based Films by Grafting or Coating

2020 ◽  
Vol 11 (2) ◽  
pp. 30 ◽  
Author(s):  
Aleksandra Miletić ◽  
Ivan Ristić ◽  
Maria-Beatrice Coltelli ◽  
Branka Pilić
Keyword(s):  
Surface Modification ◽  
Active Component ◽  
Mechanical Characterization ◽  
Natural Polymer ◽  
Natural Polymers ◽  
Hydrophilic Surfaces ◽  
Nanostructured Systems ◽  
Grafting From ◽  
Specific Challenge

Recently, the demand for the use of natural polymers in the cosmetic, biomedical, and sanitary sectors has been increasing. In order to meet specific functional properties of the products, usually, the incorporation of the active component is required. One of the main problems is enabling compatibility between hydrophobic and hydrophilic surfaces. Therefore, surface modification is necessary. Poly(lactide) (PLA) is a natural polymer that has attracted a lot ofattention in recent years. It is bio-based, can be produced from carbohydrate sources like corn, and it is biodegradable. The main goal of this work was the functionalization of PLA, inserting antiseptic and anti-inflammatory nanostructured systems based on chitin nanofibrils–nanolignin complexes ready to be used in the biomedical, cosmetics, and sanitary sectors. The specific challenge of this investigation was to increase the interaction between the hydrophobic PLA matrix with hydrophilic chitin–lignin nanoparticle complexes. First, chemical modification via the “grafting from” method using lactide oligomers was performed. Then, active coatings with modified and unmodified chitin–lignin nanoparticle complexes were prepared and applied on extruded PLA-based sheets. The chemical, thermal, and mechanical characterization of prepared samples was carried out and the obtained results were discussed.

THE APPLICATION OF FEATHER KERATIN AND ITS DERIVATIVES IN TREATMENT OF POTATO STARCH WASTEWATER

2010 ◽  
Vol 03 (03) ◽  
pp. 213-216 ◽  
Author(s):  
RONG-MIN WANG ◽  
FANG-YING LI ◽  
XIAO-JIE WANG ◽  
QUAN-FANG LI ◽  
YU-FENG HE ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Water Treatment ◽  
Removal Rate ◽  
Potato Starch ◽  
Natural Polymer ◽  
Practical Application ◽  
Natural Polymers ◽  
Feather Keratin ◽  
Starch Wastewater ◽  
Polymer Flocculant

In this paper, stable and homogeneous feather keratin was effectively extracted from feathers. Its molecular weight is 20kDa with low dispersivity. The extracted feather keratin (FK) and its derivatives (FK-ET) were used as natural polymer flocculants. It was a new kind of effective and innoxious flocculant for the COD removal of potato starch wastewater. The removal rate of COD was up to 75% under the following optimal condition: 100mL of initial wastewater (COD = 7380), T = 20°C, [FK-ET] = 0.4g/L, [Bent] = 4g/L, pH = 8.0. Compared with traditional flocculants, keratin flocculants are innoxious natural polymers. Their sludge is easy to be treated, and there is no further pollution. Also, the flocculating constituents, which containing keratin, starch, saccharide, protein and other solubility substances from wastewaters, should be reutilized. It has practical application value in water treatment as a kind of natural polymer flocculant.

Preparation and Characterization of Hydrocolloid Stabilized Silver Nanoparticles

2014 ◽  
Vol 1060 ◽  
pp. 115-118 ◽  
Author(s):  
Hathaichanok Tamiyakul ◽  
Stephan Thierry Dubas ◽  
Warangkana Warisnoicharoen
Keyword(s):  
Silver Nanoparticles ◽  
Reduction Method ◽  
Medical Application ◽  
Spherical Particles ◽  
Natural Polymers ◽  
Surface Charges ◽  
Microwave Assisted ◽  
Negative Surface ◽  
Laser Doppler Electrophoresis

Silver nanoparticles (AgNPs) are of considerable interest for medical application due to their antimicrobial activity. However, only a limited number of natural polymers have been reported as colloidal stabilizers for AgNPs. This study aimed to synthesize AgNPs using hydrocolloids, alginate and carrageenan, as stabilizers. Hydrocolloid-capped AgNPs were synthesized by two methods: M1, a reductive sodium borohydride (NaBH4) method, and M2, a microwave assisted reduction method. The synthesized AgNPs were characterized for surface plasmon resonance (SPR), size, surface charge and morphology. From the results, AgNPs stabilized by alginate (al-AgNPs) and carrageenan (ca-AgNPs) were able to be synthesized by methods M1 and M2. The SPR absorption peak around 400 nm of AgNPs represented the formation of rather spherical particles. The AgNPs formed by method M1were narrower in size distribution than that of AgNPs formed by method M2. Laser doppler electrophoresis (LDE) showed negative surface charges of al-AgNPs and ca-AgNPs because the anionic hydrocolloid polymers consist of carboxylic acid (alginate) and sulfate (carrageenan). Conclusively, AgNPs can be successfully formed and stabilized by alginate and carrageenan. Hydrocolloid-capped AgNPs are stable due to the electrostatic repulsion and steric stabilization of such polymers.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Comparison of Ion-Milling Techniques For Cross-Sectional TEM of Semiconductors

1985 ◽  
Vol 43 ◽  
pp. 166-167
Author(s):  
Julia T. Luck ◽  
C. W. Boggs ◽  
S. J. Pennycook
Keyword(s):  
Analytical Techniques ◽  
Sample Surface ◽  
Ion Milling ◽  
Cross Sectional ◽  
Reliable Technique ◽  
Near Surface ◽  
Transmission Electron ◽  
Thin Region ◽  
Transient Thermal

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

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