Effect of Glycerol on the Properties of the Cross-Linked Polyvinyl Alcohol Hydrogel Beads

2018 ◽  
Vol 3 (2) ◽  
pp. 467-470 ◽  
Author(s):  
Xuejun Zhu ◽  
Yi Zhang ◽  
Jun Deng ◽  
Xujun Luo
Keyword(s):  
Polyvinyl Alcohol ◽  
Hydrogel Beads ◽  
The Cross

Creep and dynamic mechanical behavior of cross-linked polyvinyl alcohol reinforced with cotton fiber laminate composites

2019 ◽  
Vol 39 (4) ◽  
pp. 326-335 ◽  
Author(s):  
Naman Jain ◽  
Shubhan Ali ◽  
Vinay K. Singh ◽  
Komal Singh ◽  
Nitesh Bisht ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Cotton Fiber ◽  
Water Solubility ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Laminate Composites ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
The Cross ◽  
Uptake Test

AbstractThe objective of this investigation was to fabricate cross-linked polyvinyl alcohol (PVA) based laminate composites reinforced with biaxial cotton sheets. Cross-linking was done with sulfuric acid, to overcome the water solubility of PVA. A water uptake test was performed to evaluate the effect of cross-linking on the water absorption properties of the composites. Morphology, distribution and bonding between the matrix and reinforcement of the fabricated composites were studied using scanning electron microscopy. Mechanical properties such as the tensile strength (TS), modulus of elasticity and elongation of the fabricated composites material were evaluated. There was about a 56.25% increase in the TS of the cross-linked composite as compared to the neat PVA, and at 64 wt.% of cotton fiber, there was about a 56% increase in the TS as compared to the cross-linked PVA. The thermal degradation analysis of fabricated composites material was carried out by thermogravimetric analysis. The thermal stability increased with increase in cotton fiber wt.%. The viscoelastic properties of the fabricated composites material were determined by dynamic mechanical analysis. The effects of stress (4 MPa, 6 MPa and 8 MPa) and temperature (20°C and 40°C) on creep and recovery behavior of the laminated composites were studied.

scholarly journals The cross-linked polyvinyl alcohol/hydroxyapatite nanocomposite foam

2019 ◽  
Vol 8 (3) ◽  
pp. 3149-3157 ◽  
Author(s):  
Amir Ali Ashraf ◽  
Seyed Mojtaba Zebarjad ◽  
Mohammad Jafar Hadianfard
Keyword(s):  
Polyvinyl Alcohol ◽  
Nanocomposite Foam ◽  
The Cross

Effect of Microwave Irradiation on the Cross-Linking of Polyvinyl Alcohol

2005 ◽  
Vol 78 (7) ◽  
pp. 1158-1161 ◽  
Author(s):  
N. V. Petrova ◽  
A. M. Evtushenko ◽  
I. P. Chikhacheva ◽  
V. P. Zubov ◽  
I. V. Kubrakova
Keyword(s):  
Microwave Irradiation ◽  
Polyvinyl Alcohol ◽  
Cross Linking ◽  
The Cross

scholarly journals Preparation and Characterization of Macroporous Carrageenan Beads for Enhanced Gel Filtration

1996 ◽  
Vol 1 ◽  
pp. 65
Author(s):  
Q. Li ◽  
C. C. E. Hsu ◽  
E. W. Grandmaison ◽  
M. F. A. Goosen
Keyword(s):  
Ionic Strength ◽  
Pore Structure ◽  
Surface Area ◽  
Chromatographic Separation ◽  
Gel Filtration ◽  
Total Surface Area ◽  
Environmental Scanning ◽  
Bulk Fluid ◽  
Hydrogel Beads ◽  
The Cross

Macroporous K-carrageenan beads were prepared by two–step emulsion method, chemically cross-linked characterized, and then employed for gel filtration. It has recently been recognized that convection (i.e. bulk fluid movement) through large pores (i.e. macropores ) is an effective way of enhancing the performance of chromatographic separation by improving mass transfer. The aim of our study was to determine if this concept was true for macroporous and carrageenan beads. The pore structure of the beads was analyzed by environmental scanning electronic microscopy and characterized by measuring  the total surface area and packing density. An increasing toluene content in the first emulsion was found to play an important role in creating more pores and in determining the pore structure. In addition, heat treatment of the beads was very effective for increasing the cross linking density and reducing the bead volume swelling in saline. However, treatment with steam reduced the bead surface area suggesting a change in pore structure. The cross linked hydrogel beads were stable in the pH range 1-13 and in KCI solutions at a concentration over 0.07 M. The bead size increased with a decrease in ionic strength. At low ionic strength, two of the proteins studied, cytochrome C and lysozyme, were found to adsorb to the carrageenan beads. The ionic stength also affected the fractionation range of the beads for gel filtration. The elution volume of various non-adsorbed proteins was reduced with a decrease in ionic stength. The efficiency (i.e. resolution and reduced plate heights) of carrageenanbeads in chromatographic separation was better than that of commercial Sepharose CL-6B beads , especially at high flow rates.

scholarly journals Environmentally Friendly Polyvinyl alcohol−alginate/bentonite Nanocomposite Hydrogel Beads as Efficient Adsorbents for Removal of Toxic Methylene Blue from Aqueous Solution

2021 ◽  
Author(s):  
Mona A. Aziz Aljar ◽  
Suad Rashdan ◽  
Ahmed Abd El-Fattah
Keyword(s):  
Methylene Blue ◽  
Polyvinyl Alcohol ◽  
Organic Dyes ◽  
Research Work ◽  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Nanocomposite Hydrogel ◽  
Homogeneous Surface ◽  
Hydrogel Beads

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and re-mediation. The present research work is focused on the development` and characterization of the ecofriendly polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as beneficial adsorbents for removal of toxic methylene blue (MB) from industrial water. PVA−Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating batch aqueous solutions. The experimental results indicated that the incorporation of Bent (30 w%) in the nanocomposite formulation sustained porous structure, preserved water uptake, and increased MB removal effi-ciency by 230 % compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model a high correlation coefficient. Moreover, designed beads had a good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. Adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed PVA−Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

scholarly journals Bentonite-composite polyvinyl alcohol/alginate hydrogel beads: Preparation, characterization and their use as arsenic removal devices

2020 ◽  
Vol 14 ◽  
pp. 100364
Author(s):  
Estefanía Baigorria ◽  
Leonardo A. Cano ◽  
Laura M. Sanchez ◽  
Vera A. Alvarez ◽  
Romina P. Ollier
Keyword(s):  
Polyvinyl Alcohol ◽  
Arsenic Removal ◽  
Alginate Hydrogel ◽  
Hydrogel Beads

Reactive toughening of polyvinyl alcohol hydrogel and its wastewater treatment performance by immobilization of microorganisms

RSC Advances ◽  
2015 ◽  
Vol 5 (111) ◽  
pp. 91414-91422 ◽  
Author(s):  
Yi Zhang ◽  
Bing Hui ◽  
Lin Ye
Keyword(s):  
Wastewater Treatment ◽  
Polyvinyl Alcohol ◽  
Tensile Property ◽  
Impact Resistance ◽  
Dense Network ◽  
Gel Structure ◽  
Hydrogel Beads ◽  
Treatment Performance ◽  
Hydraulic Impact ◽  
Pva Hydrogel

Toughened PVA hydrogel beads were prepared by co-crosslinking with glycerol, resulting in the formation of a uniform and dense network gel structure, and the tensile property and hydraulic impact resistance were efficiently improved.

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