Removal of Cr(VI) from Aqueous Solutions Using PVA/SA Blend Films

2013 ◽  
Vol 781-784 ◽  
pp. 2142-2145
Author(s):  
Wen Juan Fan ◽  
Hong Xiang Ge ◽  
Yu Pang ◽  
Hui Chang
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Crosslinking Agent ◽  
Chemical Properties ◽  
Solution Ph ◽  
Hydrogen Bond Interaction ◽  
Blend Films ◽  
Molecular Force ◽  
Physical And Chemical ◽  
And Chemical Properties

The different ratios (PVA and SA) of PVA/SA blend films with cross-linking structure are successfully prepared by coagulating the mixture of sodium alginate (SA) and polyvinyl alcohol (PVA) in aqueous solution, then by treating with crosslinking agent CaCl2solution. The Surface morphology and flexibility of PVA/SA blend films were studied. The results indicate there is some strong interaction and good compatibility between sodium alginate and polyvinyl alcohol molecular. The physical and chemical properties of the PSA-80(PVA:SA=4:1) blend films are obviously improved owing to a molecular force and hydrogen bond interaction. The effects of parameters of the blend film was investigated in relation to its adsorption capability for low concentration ions Cr (VI) including such as SA content of the PVA/SA film, contact time, solution pH and temperature of solution. The results indicate that the maximum adsorption rate is 95.86% at the temperature 50°C under optimized pH 4 for 60min by PSA-80 films.

Effect of low concentrations of SiO2 nanoparticles on the physical and chemical properties of sodium alginate-based films

2021 ◽  
pp. 118286
Author(s):  
Luís Marangoni Júnior ◽  
Renan Garcia da Silva ◽  
Carlos Alberto Rodrigues Anjos ◽  
Roniérik Pioli Vieira ◽  
Rosa Maria Vercelino Alves
Keyword(s):  
Sodium Alginate ◽  
Chemical Properties ◽  
Sio2 Nanoparticles ◽  
Physical And Chemical Properties ◽  
Low Concentrations ◽  
Physical And Chemical ◽  
And Chemical Properties

scholarly journals Hydrophobic Cryogels Based on Polyvinyl Alcohol and Polymeric Oil Resins

2019 ◽  
pp. 166-176
Author(s):  
Maria S. Fufaeva ◽  
Darya V. Fisenko ◽  
Vladimir N. Manzhay ◽  
Vladimir G. Bondaletov ◽  
Lyubov K. Altunina
Keyword(s):  
Polyvinyl Alcohol ◽  
Chemical Properties ◽  
Flow Properties ◽  
Road Pavement ◽  
Binder Component ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Pavement Construction ◽  
Physical And Chemical ◽  
And Chemical Properties

The paper presents the results of studies of the flow properties of viscous compositions consisting of polyvinyl alcohol, polymeric oil resin, and water. After a freeze-thaw cycle three-component cryogels are formed from them. Mechanical, thermal, physical, and chemical properties of the resulted elastic samples are studied. The prospects of using hydrophobic cryogels filled with polymeric oil resin as a binder component for road pavement construction are presented

scholarly journals Characteristics of Sodium Alginate Extracted from Turbinaria sp. and Sargassum sp.

2018 ◽  
Vol 13 (2) ◽  
pp. 79 ◽  
Author(s):  
Rinta Kusumawati ◽  
Jamal Basmal ◽  
Bagus Sediadi Bandol Utomo
Keyword(s):  
Water Content ◽  
Sodium Alginate ◽  
Raw Materials ◽  
Chemical Properties ◽  
Brown Seaweed ◽  
Extraction Process ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Characterization of sodium alginate extracted from two species of brown seaweed (Turbinaria sp. and Sargassum sp.) has been conducted. The aim of the study was to evaluate physical and chemical properties of the two different types of sodium alginates produced from this extraction process. Extraction was conducted in alkaline solution followed by acid treatment with the following steps: sortation of seaweed, washing, alkaline extraction, bleaching, alginic acid and sodium alginate conversion, dehydration using isopropyl alcohol (IPA), drying, chopping and grinding. Each extraction was conducted in duplicate using approximately 1 kg of the raw materials. The physical and chemical properties of the final products (sodium alginate powders) were analyzed. The results of the analysis were as follows: the yield of alginate powder from Turbinaria sp. was 14.77% having water content of 13.48%; whiteness degree of 23.77%; and viscosity of 133.67 cPs while the yield of sodium alginate powder extracted from Sargassum sp. was 24.56% with water content of 12.69%; whiteness degree of 43.80%; and viscosity of 217.50 cPs. Both alginate powders had better physical characteristics compared to commercial grade alginate which had water content of 16.07%, whiteness degree of 29.37%, and viscosity of 102.67cPs.

scholarly journals pH dependence of C·A, G·A and A·A mismatches in the stem of precursor microRNA-31

2021 ◽  
Author(s):  
Anita Kotar ◽  
Sicong Ma ◽  
Sarah C Keane
Keyword(s):  
Base Pair ◽  
Thermal Denaturation ◽  
Ph Dependence ◽  
Chemical Properties ◽  
Mature Mirnas ◽  
Solution Ph ◽  
Physical And Chemical ◽  
Processing Steps ◽  
And Chemical Properties

MicroRNAs (miRNAs) are important regulators of post-transcriptional gene expression. Mature miRNAs are generated from longer transcripts (primary, pri- and precursor, pre-miRNAs) through a series of highly coordinated enzymatic processing steps. The sequence and structure of these pri- and pre-miRNAs play important roles in controlling their processing. Both pri- and pre-miRNAs adopt hairpin structures with imperfect base pairing in the helical stem. Here, we investigated the role of three base pair mismatches (A·A, G·A, and C·A) present in pre-miRNA-31. Using a combination of NMR spectroscopy and thermal denaturation, we found that the three base pair mismatches displayed unique structural properties, including varying dynamics and sensitivity to solution pH. These studies deepen our understanding of how the physical and chemical properties of base pair mismatches influence RNA structural stability.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

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