scholarly journals New Poly(β-Cyclodextrin)/Poly(Vinyl Alcohol) Electrospun Sub-Micrometric Fibers and Their Potential Application for Wastewater Treatments

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 482 ◽  
Author(s):  
Anastasia Anceschi ◽  
Fabrizio Caldera ◽  
Moira Bertasa ◽  
Claudio Cecone ◽  
Francesco Trotta ◽  
...  
Keyword(s):  
Metal Ions ◽  
Vinyl Alcohol ◽  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Chemical Properties ◽  
Optical Emission ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Fiber Morphology ◽  
Scanning Calorimetry

Cyclodextrin (CD)-based polymers are known to efficiently form molecular inclusion complexes with various organic and inorganic guest compounds. In addition, they also have a great potential as metal complexes because deprotonated hydroxyls can strongly bind metal ions under alkaline conditions. The range of environmental conditions for polycyclodextrin/metal ion complexation can be extended by the polymerization of CDs with polyacids. This article describes the preparation and characterization of a new type of poly(β-cyclodextrin) (Poly-βCD) sub-micrometric fibers and explores their potential as metal ion sorbents. A water-soluble hyper-branched β-cyclodextrin polymer was blended with poly(vinyl alcohol) (PVA) and here used to improve the mechanical and morphological features of the fibers. Solutions with a different Poly-βCD/PVA ratio were electrospun, and the fibers were cross-linked by a post-spinning thermal treatment at 160 °C to ensure non-solubility in water. The fiber morphology was analyzed by scanning electron microscopy (SEM) before and after the curing process, and physical-chemical properties were studied by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The capability of the insoluble cyclodextrin-based fibers to remove heavy metals from wastewaters was investigated by testing the adsorption of Cu2+ and Cd2+ using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The results suggest that the poly(β-cyclodextrin)/poly(vinyl alcohol) sub-micrometric fibers can complex metal ions and are especially effective Cu2+ sorbents, thus opening new perspectives to the development of fibers and membranes capable of removing both metal ions and organic pollutants.

scholarly journals New Polymers for Needleless Electrospinning from Low-Toxic Solvents

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Martin Wortmann ◽  
Natalie Frese ◽  
Lilia Sabantina ◽  
Richard Petkau ◽  
Franziska Kinzel ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
New Technology ◽  
Acrylonitrile Butadiene Styrene ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Fiber Morphology ◽  
Water Soluble Polymers ◽  
Wide Range ◽  
Solvent Additive ◽  
Low Toxic

Electrospinning is a new technology whose scope is gradually being developed. For this reason, the number of known polymer–solvent combinations for electrospinning is still very low despite the enormous variety of substances that are potentially available. In particular, electrospinning from low-toxic solvents, such as the use of dimethyl sulfoxide (DMSO) in medical technology, is rare in the relevant scientific literature. Therefore, we present in this work a series of new polymers that are applicable for electrospinning from DMSO. From a wide range of synthetic polymers tested, poly(vinyl alcohol) (PVOH), poly(2ethyl2oxazolene) (PEOZ), and poly(vinylpyrrolidone) (PVP) as water-soluble polymers and poly(styrene-co-acrylonitrile) (SAN), poly(vinyl alcohol-co-ethylene) (EVOH), and acrylonitrile butadiene styrene (ABS) as water-insoluble polymers were found to be suitable for the production of nanofibers. Furthermore, the influence of acetone as a volatile solvent additive in DMSO on the fiber morphology of these polymers was investigated. Analyses of the fiber morphology by helium ion microscopy (HIM) showed significantly different fiber diameters for different polymers and a reduction in beads and branches with increasing acetone content.

scholarly journals Radiation Synthesis and Characterization of Poly(Vinyl Alcohol)/ Acrylamide/ TiO2/ SiO2 Nanocomposite for Removal of Metal Ion and Dye From Waste Water

2021 ◽  
Author(s):  
Ahmed Elbarbary ◽  
Yasser H. Gad
Keyword(s):  
Adsorption Capacity ◽  
Vinyl Alcohol ◽  
Metal Ion ◽  
Chemical Properties ◽  
Poly Vinyl Alcohol ◽  
Blue Dye ◽  
High Adsorption ◽  
Γ Irradiation ◽  
Experimental Conditions ◽  
High Adsorption Capacity

Abstract An effective and novel adsorbent of poly(vinyl alcohol)/polyacrylamide/TiO2/SiO2 (PVA-co-AAm/TiO2/SiO2) nanocomposite synthesized by γ-irradiation polymerization of PVA and AAm in presence of TiO2/SiO2 nanoparticles at different irradiation doses (10, 30 and 50 kGy) for removal of Cu(II) ions and basic blue 3 dye from their aqueous solutions. FT-IR, TEM, XRD, SEM, EDS and DLS analyzed the chemical properties of nanocomposites. The nanocomposite prepared at 30 kGy (PVA-co-AAm/TiO2/SiO2-30) shows high swelling of 197.7 (%) and gelation of 93.1 %. The adsorption capacity (mg/g) and removal (%) of basic blue 3 dye and Cu(II) ions onto nanocomposites by varying experimental conditions were investigated. The PVA-co-AAm/TiO2/SiO2-30 showed high adsorption capacity 3 folds rather than PVA-co-AAm. The equilibrium adsorption for basic blue 3 dye and Cu(II) was 123.9 mg/g and 190.3 mg/g with removal of 82.6 and 95.1 %, respectively. The results of the adsorption of dye or metal ions follow the Pseudo-second order adsorption kinetic, fit with the Langmuir isotherm and the adsorption process is endothermic and spontaneous in nature. The results revealed that the PVA-co-AAm/TiO2/SiO2 nanocomposites could be employed as an effectual adsorbent for adsorption of basic blue dye and Cu(II) ions from wastewater with high adsorption capacity and recovery.

scholarly journals Surface modified polythiophene/Al2O3 and polyaniline/Al2O3 nanocomposites using poly(vinyl alcohol) for the removal of heavy metal ions from water: kinetics, thermodynamic and isotherm studies

2021 ◽  
Author(s):  
Zeynab Karimi ◽  
Reza Khalili ◽  
Mohammad Ali Zazouli
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Vinyl Alcohol ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Adsorption Process ◽  
Oxidative Polymerization ◽  
Ion Concentration ◽  
Poly Vinyl Alcohol ◽  
Order Kinetic

Abstract In this study, polythiophene/Al2O3 (PTh/Al2O3) and polyaniline/Al2O3 (PAn/Al2O3) nanocomposites in the presence of poly(vinyl alcohol) (PVA) as the surfactant were synthesized via in situ chemical oxidative polymerization method in aqueous medium. The synthesized nanocomposites were characterized by Scanning electron microscopy (SEM), Fourier transform-infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Results indicated that the Al2O3 and poly(vinyl alcohol) influenced the properties of synthesized nanocomposites. The aim of this research was to investigate the sorption characteristic of polythiophene and polyaniline nanocomposites for the removal of heavy metal cations including Pb(II), Zn(II) and Cd(II) from aqueous solution. The factors that affected the adsorption equilibrium as well as the removal efficiency of the nanoadsorbents, i.e., contact time, metal ion concentration, pH and adsorption conditions were investigated in detail. From the kinetic results, it was concluded that the pseudo-second-order kinetic model was found to the best at describing the adsorption process for Pb(II), Zn(II) and Cd(II) on PTh-PVA/Al2O3 and PAn-PVA/Al2O3. In addition, thermodynamic analysis suggests the endothermic and spontaneous nature of the present adsorption process with increased entropy on PTh-PVA/Al2O3 and PAn-PVA/Al2O3. The results suggest polythiophene, polyaniline and their nanocomposites have great potential to be used as efficient absorbent for the removal of heavy metal ions from water.

The Synthesis of High Molecular Weight Partially Hydrolysed Poly(vinyl alcohol) Grades Suitable for Nanoparticle Fabrication

2008 ◽  
Vol 8 (11) ◽  
pp. 5739-5747 ◽  
Author(s):  
Jasminder Chana ◽  
Ben Forbes ◽  
Stuart Allen Jones
Keyword(s):  
Vinyl Alcohol ◽  
High Probability ◽  
Chemical Properties ◽  
Synthetic Polymer ◽  
Partial Hydrolysis ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Manufacture Process ◽  
Wide Range ◽  
Hydrolysis Of

Poly(vinyl alcohol) (PVA) is a highly versatile synthetic polymer that is formed by full or partial hydrolysis of poly(vinyl acetate) (PVAc). A wide range of PVA partially hydrolysed grades are commercially available, but the amphiphilic grades of the polymer (30–60% hydrolysis), which probably the most interesting in terms of drug delivery, are not readily available. As a consequence few studies have assessed the application of low hydrolysis PVA polymers to form nanocarriers. The aims of this study were to synthesise amphiphilic grades of PVA on a laboratory scale, analyse their chemical properties and determine whether these grades could be used to form nanoparticles. PVA 30%, PVA 40%, PVA 50% and PVA 60% were synthesised via direct saponification of PVAc. All grades of PVA synthesised had degrees of hydrolysis close to those predicted from the stoichiometry of the saponification reaction. The PVA grades displayed <1.5% batch to batch variability (n = 3) in terms of percentage hydrolysis, demonstrating the manufacture process was both reproducible and predictable. Analysis of the polymer characteristics using 13C nuclear magnetic resonance and differential scanning calorimetry revealed that all PVA grades contained block distributions (i.e., η < 1) of vinyl alcohol monomers (η ranged from 0.33–0.45) with a high probability of adjacency calculated for the hydroxylated units (POH ranged 0.926–0.931). All the grades of PVA formed nanoparticles using a precipitation technique with a trend towards smaller particle size with increasing degree of PVA hydrolysis; PVA 30% resulted in significantly larger nanoparticles (225 nm) compared to PVA 40–60% (137–174 nm).

scholarly journals Thickness-dependent humidity sensing by poly(vinyl alcohol) stabilized Au–Ag and Ag–Au core–shell bimetallic nanomorph resistors

2018 ◽  
Vol 5 (6) ◽  
pp. 171986 ◽  
Author(s):  
Parag Adhyapak ◽  
Rohini Aiyer ◽  
Sreekantha Reddy Dugasani ◽  
Hyeong-U Kim ◽  
Chung Kil Song ◽  
...  
Keyword(s):  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Nanocomposite Materials ◽  
Water Soluble ◽  
Shell Structures ◽  
Poly Vinyl Alcohol ◽  
Core Shell ◽  
Water Soluble Polymer ◽  
Bimetallic Nanostructures

We herein report a simple chemical route to prepare Au–Ag and Ag–Au core–shell bimetallic nanostructures by reduction of two kinds of noble metal ions in the presence of a water-soluble polymer such as poly(vinyl alcohol) (PVA). PVA was intentionally chosen as it can play a dual role of a supporting matrix as well as stabilizer. The simultaneous reduction of metal ions leads to an alloy type of structure. Ag(c)–Au(s) core–shell structures display tendency to form prismatic nanostructures in conjunction with nanocubes while Au(c)–Ag(s) core–shell structures show formation of merely nanocubes. Although UV–visible spectroscopy and X-ray photoelectron spectroscopy analyses of the samples typically suggest the formation of both Ag(c)–Au(s) and Au(c)–Ag(s) bimetallic nanostructures, the definitive evidence comes from high-resolution transmission electron microscopy–high-angle annular dark field elemental mapping in the case of Au(c)–Ag(s) nanomorphs only. The resultant nanocomposite materials are used to fabricate resistors on ceramic rods having two electrodes by drop casting technique. These resistors are examined for their relative humidity (RH) response in the range (2–93% RH) and both the bimetallic nanocomposite materials offer optimized sensitivity of about 20 Kohm/% RH and 300 ohm/% RH at low and higher humidity conditions, respectively, which is better than that of individual nanoparticles.

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

scholarly journals Composite Poly(vinyl alcohol)-Based Nanofibers Embedding Differently-Shaped Gold Nanoparticles: Preparation and Characterization

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1604
Author(s):  
Andrea Dodero ◽  
Maila Castellano ◽  
Paola Lova ◽  
Massimo Ottonelli ◽  
Elisabetta Brunengo ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Ad Hoc ◽  
Chemical Reduction ◽  
Chemical Properties ◽  
Single Step ◽  
Gold Nanostructures ◽  
Poly Vinyl Alcohol ◽  
Spherical Nanoparticles ◽  
Potential Applications ◽  
New Perspective

Poly(vinyl alcohol) nanofibrous mats containing ad hoc synthesized gold nanostructures were prepared via a single-step electrospinning procedure and investigated as a novel composite platform with several potential applications. Specifically, the effect of differently shaped and sized gold nanostructures on the resulting mat physical-chemical properties was investigated. In detail, nearly spherical nanoparticles and nanorods were first synthesized through a chemical reduction of gold precursors in water by using (hexadecyl)trimethylammonium bromide as the stabilizing agent. These nanostructures were then dispersed in poly(vinyl alcohol) aqueous solutions to prepare nanofibrous mats, which were then stabilized via a humble thermal treatment able to enhance their thermal stability and water resistance. Remarkably, the nanostructure type was proven to influence the mesh morphology, with the small spherical nanoparticles and the large nanorods leading to thinner well defined or bigger defect-rich nanofibers, respectively. Finally, the good mechanical properties shown by the prepared composite mats suggest their ease of handleability thereby opening new perspective applications.

Effect of Cobalt Stearate and Vegetable Oil on Uv and Biodegradation of Linear Low-Density Poly(Ethylene)-Poly(Vinyl Alcohol) Blends

2011 ◽  
Vol 2 (4) ◽  
pp. 131-148 ◽  
Author(s):  
Francis Vidya ◽  
Subin S. Raghul ◽  
Sarita G Bhat ◽  
Eby Thomas Thachil
Keyword(s):  
Vegetable Oil ◽  
Vinyl Alcohol ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Low Density ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Degradation Behaviour ◽  
Moulding Process ◽  
Poly Ethylene

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found

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