IMPROVE THE NATIVE CHARACTERISTICS OF POLYSACCHARIDES BY GRAFTING THROUGH THE GAMMA RADIATION: A REVIEW

2016 ◽  
Vol 2 (3) ◽  
pp. 151-159 ◽  
Author(s):  
Deepak Kumar
Keyword(s):  
Graft Copolymers ◽  
Low Cost ◽  
Natural Polymers ◽  
Γ Radiation ◽  
Agricultural Resources ◽  
Free Radical Initiator ◽  
Methods Of Synthesis ◽  
Graft Yield ◽  
Grafting Copolymerization ◽  
Grafting Through

Polysaccharides are bio-degradable, inexpensive and easily available from consistent agricultural resources. Polysaccharides and their derivatives represent a group of polymer widely used in pharmaceutical and biomedical fields. The biodegradability of natural polymers reduces their shelf life. Grafting copolymerization technique is a most effective fascinating way for chemical modification of native characteristics of polysaccharides with maximum possibilities for improving the properties of polysaccharides and enhanced the range of exploitation.While the major difficulty facing us during synthesizing a graft copolymers reaction, is the lack of commercial methods of synthesis and lower percent graft yield. It is well known that the most important methods of synthesis engage the employ of chemical free radical initiator i.e. conventional based methods. Graft copolymerization through γ-radiation method is a better method of grafting in comparison to a chemical method and exhibits a great potential to synthesize the graft copolymers by virtue of its higher efficiency, low cost, higher thermal stability as well as enhanced the yield of the graft copolymer. Future prospective of irradiation technique would be significant impacts to develop of polymerization.

scholarly journals Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3694
Author(s):  
Luminita Georgeta Confederat ◽  
Cristina Gabriela Tuchilus ◽  
Maria Dragan ◽  
Mousa Sha’at ◽  
Oana Maria Dragostin
Keyword(s):  
Antimicrobial Activity ◽  
Low Cost ◽  
Hydroxyl Groups ◽  
Pharmacological Properties ◽  
Natural Polymers ◽  
Economic Sectors ◽  
Physico Chemical ◽  
Long Time ◽  
Resistant Strains ◽  
Strength And Durability

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

PNIPAM-based graft copolymers prepared using potassium persulfate as free-radical initiator: synthesis reproducibility

2016 ◽  
Vol 294 (6) ◽  
pp. 981-991 ◽  
Author(s):  
Nívia N. Marques ◽  
Bruna V. Lima ◽  
Valdelice R. Silveira ◽  
Bruna L. B. Lima ◽  
Ana M. S. Maia ◽  
...  
Keyword(s):  
Free Radical ◽  
Graft Copolymers ◽  
Potassium Persulfate ◽  
Radical Initiator ◽  
Free Radical Initiator

Synthesis, Characterization, Applications, and Toxicity of Green Synthesized Nanoparticles

2021 ◽  
Vol 22 ◽  
Author(s):  
João Marcos Pereira Galúcio ◽  
Sorrel Godinho Barbosa de Souza ◽  
Arthur Abinader Vasconcelos ◽  
Alan Kelbis Oliveira Lima ◽  
Kauê Santana da Costa ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Low Cost ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Industrial Applications ◽  
Synthesis Methods ◽  
Methods Of Synthesis ◽  
Food Applications ◽  
Living Organisms ◽  
Harmful Effects

: Nanotechnology is a cutting-edge area with numerous industrial applications. Nanoparticles are structures that have dimensions ranging from 1–100 nm which exhibit significantly different mechanical, optical, electrical, and chemical properties when compared with their larger counterparts. Synthetic routes that use natural sources, such as plant extracts, honey, and microorganisms are environmentally friendly and low-cost methods that can be used to obtain nanoparticles. These methods of synthesis generate products that are more stable and less toxic than those obtained using conventional methods. Nanoparticles formed by titanium dioxide, zinc oxide, silver, gold, and copper, as well as cellulose nanocrystals are among the nanostructures obtained by green synthesis that have shown interesting applications in several technological industries. Several analytical techniques have also been used to analyze the size, morphology, hydrodynamics, diameter, and chemical functional groups involved in the stabilization of the nanoparticles as well as to quantify and evaluate their formation. Despite their pharmaceutical, biotechnological, cosmetic, and food applications, studies have detected their harmful effects on human health and the environment; and thus, caution must be taken in uses involving living organisms. The present review aims to present an overview of the applications, the structural properties, and the green synthesis methods that are used to obtain nanoparticles, and special attention is given to those obtained from metal ions. The review also presents the analytical methods used to analyze, quantify, and characterize these nanostructures.

Infrared spectra of polystyrene-acrylonitrile and perchlorovinyl-acrylonitrile graft copolymers obtained under the action of γ-radiation

1963 ◽  
Vol 4 (2) ◽  
pp. 274-280
Author(s):  
Kh.U. Usmanov ◽  
P.P. Larin ◽  
Yu.T. Tashpulatov ◽  
U.N. Musayev ◽  
R.S. Tillayev
Keyword(s):  
Infrared Spectra ◽  
Graft Copolymers ◽  
Γ Radiation

Green Synthesis of Nanocomposites

2022 ◽  
pp. 77-100
Author(s):  
Meenal D. Patil ◽  
Suprimkumar D. Dhas ◽  
Annasaheb V. Moholkar
Keyword(s):  
Green Synthesis ◽  
Low Cost ◽  
Future Generation ◽  
Research Area ◽  
Future Prospects ◽  
Comprehensive Overview ◽  
New Era ◽  
Methods Of Synthesis ◽  
Potential Applications ◽  
Negative Impacts

Nanotechnology has been a dynamic research area over the past few decades because it assures the resolution to the problems that hamper progress. Currently, a new era of ‘green synthesis' is an emerging multidisciplinary field in nanotechnology which employs reliable, sustainable, low-cost, non-hazardous, and eco-friendly techniques. Green synthesis is considered a vital tool to reduce the negative impacts accompanying the traditional methods of synthesis for NPs commonly employed in industry and laboratory. This chapter unveils a comprehensive overview of the recent research on available green techniques for the synthesis of various nanocomposites in order to solve future generation challenges. This chapter also focuses on the green synthesis of various nanocomposites, synthesis parameters, potential applications, merits/demerits, and future prospects.

Starch/Poly(ε-caprolactone) Graft Copolymers Synthetized by γ-Radiation and Their Application as Compatibilizer in Polymer Blends

2019 ◽  
Vol 27 (12) ◽  
pp. 2906-2914
Author(s):  
Olivia V. López ◽  
Mario D. Ninago ◽  
M. M. Soledad Lencina ◽  
Andrés E. Ciolino ◽  
Marcelo A. Villar ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Graft Copolymers ◽  
Γ Radiation

Polymer micelles from tadpole-shaped amphiphilic block-graft copolymers prepared by “Grafting-through” ATRP

2009 ◽  
Vol 51 (11-12) ◽  
pp. 1210-1217 ◽  
Author(s):  
Shigeki Ohno ◽  
Alper Nese ◽  
Brian Cusick ◽  
Tomasz Kowalewski ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Graft Copolymers ◽  
Polymer Micelles ◽  
Grafting Through

scholarly journals Green and efficient three-component synthesis of 4H-pyran catalysed by CuFe 2 O 4 @starch as a magnetically recyclable bionanocatalyst

2020 ◽  
Vol 7 (7) ◽  
pp. 200385
Author(s):  
Maryam Kamalzare ◽  
Mohammad Bayat ◽  
Ali Maleki
Keyword(s):  
Low Cost ◽  
Environmentally Benign ◽  
Pharmaceutical Chemistry ◽  
X Ray Diffraction ◽  
Natural Polymers ◽  
X Ray ◽  
Benign Nature ◽  
Catalytic Behaviour ◽  
Work Up ◽  
Derivatives Of

The development of simple, practical and inexpensive catalysis systems using natural materials is one of the main goals of pharmaceutical chemistry as well as green chemistry. Owing to the ability of easy separation of nanocatalyst, those goals could be approached by applying heterogeneous bionanocatalyst in combination with magnetic nanoparticles. Starch is one of the most abundant natural polymers; therefore, preparing bionanocatalyst from starch is very valuable as starch is largely available and inexpensive. An ecologically benign and efficacious heterogeneous nanocatalyst was prepared based on a biopolymer, and its attributes and morphology were specified by using Fourier transform infrared spectra, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal analysis and vibrating sample magnetometer measurements; followed by studying catalytic behaviour of bionanocomposite in a multicomponent reaction to synthesize of 4H-pyran derivatives. 4H-pyran is extremely valuable in pharmaceutical chemistry, and the development of methods for synthesis of different derivatives of 4H-pyran is momentous. Revealing environmentally benign nature, mild condition, easy work-up, low cost and non-toxicity are some of the advantages of this protocol. Besides, the bionanocomposite was recovered using an external magnetic bar and could be re-used at least six times with no further decrease in its catalytic activity.

Graft copolymers containing poly(3-hydroxyalkanoates) — A review on their synthesis, properties, and applications

2008 ◽  
Vol 86 (6) ◽  
pp. 570-578 ◽  
Author(s):  
Sophie Nguyen
Keyword(s):  
Graft Copolymer ◽  
Main Chain ◽  
Graft Copolymers ◽  
Preparation Methods ◽  
Synthesis Properties ◽  
Grafting Through ◽  
Grafting From ◽  
Grafting Onto

The use of the poly(3-hydroxyalkanoates) in copolymer synthesis has received much interest, as the microbial polyester segments can bring interesting properties, such as biodegradability and biocompatibility. The synthesis, properties, and applications of graft copolymers containing poly(3-hydroxyalkanoates) as main chain or branches are reviewed here, with emphasis on the different preparation methods, which fit into the three main synthesis strategies of graft copolymers: “grafting onto”, “grafting from”, and “grafting through” or macromonomer methods.Key words: poly(3-hydroxyalkanoates), graft copolymer, synthesis, properties, applications.

scholarly journals Miniature low-cost γ-radiation sensor for localization of radioactively marked lymph nodes

2021 ◽  
pp. 095441192110589
Author(s):  
Merlin Behling ◽  
Felix Wezel ◽  
Peter P Pott
Keyword(s):  
Minimally Invasive ◽  
Lymph Nodes ◽  
Early Stage ◽  
Imaging Techniques ◽  
Low Cost ◽  
In Vitro Tests ◽  
Γ Radiation ◽  
Sensor Head ◽  
Radiation Sensor ◽  
Validation Experiment

Detection of metastasis spread at an early stage of disease in lymph nodes can be achieved by imaging techniques, such as PET and fluoride-marked tumor cells. Intraoperative detection of small metastasis can be problematic especially in minimally invasive surgical settings. A γ-radiation sensor can be inserted in the situs to facilitate intraoperative localization of the lymph nodes. In the minimally invasive setting, the sensor must fit through the trocar and for robot-aided interventions, a small, capsule-like device is favorable. Size reduction could be achieved by using only a few simple electronic parts packed in a single-use sensor-head also leading to a low-cost device. This paper first describes the selection of an appropriate low-cost diode, which is placed in a sensor head (Ø 12 mm) and characterized in a validation experiment. Finally, the sensor and its performance during a detection experiment with nine subjects is evaluated. The subjects had to locate a 137Cs source (138 kBq activity, 612 keV) below a wooden plate seven times. Time to accomplish this task and error rate were recorded and evaluated. The time needed by the subjects to complete each run was 95 ± 68.1 s for the first trial down to 40 ± 23.9 s for the last. All subjects managed to locate the 137Cs source precisely. Further reduction in size and a sterilizable housing are prerequisites for in vitro tests on explanted human lymph nodes and finally in vivo testing.

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