scholarly journals Assessment of Toxicity and Biodegradability of Poly(vinyl alcohol)-Based Materials in Marine Water

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3742
Author(s):  
Alonso-López Olalla ◽  
López-Ibáñez Sara ◽  
Beiras Ricardo
Keyword(s):  
Polyvinyl Alcohol ◽  
Aquatic Toxicity ◽  
Oxygen Demand ◽  
Paracentrotus Lividus ◽  
New Product ◽  
Poly Vinyl Alcohol ◽  
Biobased Polymers ◽  
Potential Impact ◽  
Plastic Products ◽  
Standard Toxicity Test

Due to the continuous rise in conventional plastic production and the deficient management of plastic waste, industry is developing alternative plastic products made of biodegradable or biobased polymers. The challenge nowadays is to create a new product that combines the advantages of conventional plastics with environmentally friendly properties. This study focuses on the assessment of the potential impact that polyvinyl alcohol (PVA)-based polymers may have once they are released into the marine environment, in terms of biodegradation in seawater (assessed by the percentage of the Theoretical Oxygen Demand, or % ThOD, of each compound) and aquatic toxicity, according to the standard toxicity test using Paracentrotus lividus larvae. We have tested three different materials: two glycerol-containing PVA based ones, and another made from pure PVA. Biodegradation of PVA under marine conditions without an acclimated inoculum seems to be negligible, and it slightly improves when the polymer is combined with glycerol, with a 5.3 and 8.4% ThOD achieved after a period of 28 days. Toxicity of pure PVA was also negligible (<1 toxic units, TU), but slightly increases when the material included glycerol (2.2 and 2.3 TU). These results may contribute to a better assessment of the behavior of PVA-based polymers in marine environments. Given the low biodegradation rates obtained for the tested compounds, PVA polymers still require further study in order to develop materials that are truly degradable in real marine scenarios.

scholarly journals Photoselection of Luminescent Molecules in Anisotropic Media in the Case of Two-Photon Excitation. Part II. Experimental Studies of Hoechst 33342 in Stretched Polyvinyl alcohol) Films

1996 ◽  
Vol 51 (9) ◽  
pp. 1037-1041 ◽  
Author(s):  
A. Kawski ◽  
Z. Gryczyński ◽  
I. Gryczyński ◽  
J. R. Lakowicz ◽  
G. Piszczek
Keyword(s):  
Polyvinyl Alcohol ◽  
Vinyl Alcohol ◽  
Experimental Studies ◽  
Poly Vinyl Alcohol ◽  
Hoechst 33342 ◽  
Emission Anisotropy ◽  
Two Photon ◽  
Photon Excitation ◽  
Polyvinyl Alcohol Films ◽  
Two Photon Excitation

Abstract It was found by investigating dichroism and emission anisotropy in the case of one-and two-photon excitation of Hoechst 33342 [bis-benzimide,2,5'-bi-1H-benzimidazole, 2'-(4-ethoxyphenyl)-5-5(4-methyl-1-piperazinyl)] in stretched poly(vinyl alcohol) (PVA) films, that the absorption and fluorescence transition moments lie along the long molecular axis of the molecule studied. The slight deviation of the transition moment direction in fluorescence (about 8°) from that in absorption can be due to the incomplete linearity of the Hoechst molecule.

scholarly journals Synthesis of proton exchange membranes for dual-chambered microbial fuel cells

2018 ◽  
Vol 83 (5) ◽  
pp. 611-623 ◽  
Author(s):  
Sandeep Dharmadhikari ◽  
Prabir Ghosh ◽  
Manivannan Ramachandran
Keyword(s):  
Fuel Cells ◽  
Water Uptake ◽  
Microbial Fuel Cells ◽  
Oxygen Demand ◽  
Proton Exchange Membranes ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Poly Vinyl Alcohol ◽  
Precursor Material ◽  
Anodic Chamber

Proton exchange membranes (PEMs) were synthesized using three different compositions of poly(oxyethylene) (POE), poly(vinyl alcohol) (PVA), chitosan (CS) and phosphoric acid (PA) in weight ratios of 1:1:1:1, 1:2:1:1 and 1:3:1:1 by physical blending and the casting method. Water uptake of the membrane increases with increasing concentration of PVA. A higher percentage of water uptake signifies a higher ion exchange capacity (IEC) of the synthesized membrane. The synthesized membranes were evaluated in microbial fuel cells (MFCs) and the performance observed. The synthesized membranes were characterized for identification of precursor material and inter polymer interactions using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis, respectively. The removal of chemical oxygen demand (COD) depends on the microbial activity in the anodic chamber. In the present study, the composition of the membrane was optimized and compared with other membranes that had been synthesized by different compositions of all materials. COD removal in the MFC-3 setup connected with an M-3 membrane was found to be 88 %.

Substituent Effects on the Luminescence of 2-Substituted 3-Methylquinoxalines in Poly (Vinyl Alcohol) Films*

1991 ◽  
Vol 46 (4) ◽  
pp. 304-306 ◽  
Author(s):  
Z. Gryczyński ◽  
A. Kawski
Keyword(s):  
Polyvinyl Alcohol ◽  
Temperature Dependence ◽  
Vinyl Alcohol ◽  
Substituent Effects ◽  
Quantum Yields ◽  
Poly Vinyl Alcohol ◽  
Band Position ◽  
Fluorescence And Phosphorescence ◽  
Polyvinyl Alcohol Films

Abstract The effect of 2-substitutions (NH2 . O, CH3O, CI. Br) in 3-methylquinoxalines on the fluorescence and phosphorescence band position and intensity at 293 K, and the temperature dependence of their fluorescence and phosphorescence quantum yields were investigated in polyvinyl alcohol) films

Characterization of Treated Effluent from a Chemithermomechanical Pulping Process Using Macroporous Resins

1997 ◽  
Vol 32 (4) ◽  
pp. 795-814 ◽  
Author(s):  
K.M. Agbekodo ◽  
P.M. Huck ◽  
S.A. Andrews ◽  
S. Peldszus
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Oxygen Demand ◽  
Macroporous Resins ◽  
Treated Effluent ◽  
Chlorine Demand ◽  
Potential Impact ◽  
High Concentrations ◽  
Chemithermomechanical Pulping

Abstract This study developed a characterization of the organic matter remaining in a chemithermomechanical pulping (CTMP) effluent after biological treatment and evaluated the potential impact of this effluent when discharged into the receiving environment. The methodology employed involved fractionation with macroporous resins to allow for the isolation of hydrophobic and hydro-philic organic materials. The study also examined the treated effluent’s reactivity with chlorine, a typical drinking water disinfectant, in order to assess the formation potential of chlorinated by-products and the chlorine demand in a downstream drinking water treatment plant. Results showed that the dissolved organic carbon (DOC) in a treated effluent from a CTMP mill consisted of 87% hydrophobic material (primarily humic substances), 5% hydrophilic acids and 3 to 4% nitrogenous compounds. At least 95% of the DOC was isolated using three different macroporous resins. The chlorine demand of the biotreated CTMP effluent was two to three times higher than is typical for natural organic matter from surface water. This indicated that the organic material in the CTMP effluent was highly reactive with chlorine and will likely be reactive with other oxidants such as ozone, which is also applied in the drinking water industry. Moreover, the disinfection by-products chloroform and trichloroacetic acid were formed in high concentrations as a result of chlorination. The biotreated CTMP effluent had a high chemical oxygen demand (at least 1,100 mg/L) but a relatively low biochemical oxygen demand (less than 100 mg/L), which was to be expected after biological treatment. Hence, discharge of these effluents could release high concentrations of non- or slowly biodegradable organic matter into the downstream aquatic environment. Water pollution control policies should therefore consider the potential impact of treated effluents from CTMP mills with regard to their high DOC and the potential for chlorinated by-product formation upon drinking water disinfection.

An Economic Design Change Method

2003 ◽  
Vol 125 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Christoph Roser ◽  
David Kazmer ◽  
James Rinderle
Keyword(s):  
Engineering Design ◽  
New Product ◽  
Economic Benefits ◽  
Product Performance ◽  
Engineering Change ◽  
Design Change ◽  
Design Changes ◽  
Design Alternatives ◽  
Potential Impact ◽  
Design Defects

New product design as well as design revision to remedy defects is complicated by an inability to precisely predict product performance. Designers often find that they are confident about the performance of some design alternatives and uncertain about others. Similarly, alternative design changes may differ substantially in uncertainty, potential impact, and cost. This paper describes a method for including the effects of uncertainty in the evaluation of economic benefits of various design change options. The results indicate that the most profitable change option sequence depends not only on relative costs but also on the relative degree of uncertainty and on the magnitude of the potential design defects. The method demonstrates how design change alternatives can be compared using the engineering design of a beam. Finally, the validity of some common engineering change heuristics are discussed relative to their associated, quantitatively determined limits.

Dehydration Sensing of a Polyvinyl Alcohol Film via Plasmonic Nanoparticles

MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 299-304
Author(s):  
Milana O. Lisunova
Keyword(s):  
Refractive Index ◽  
Polyvinyl Alcohol ◽  
Real Time ◽  
Rate Constant ◽  
Vinyl Alcohol ◽  
Plasmonic Nanoparticles ◽  
Poly Vinyl Alcohol ◽  
Dehydration Rate ◽  
Polyvinyl Alcohol Film

ABSTRACTIn situ, real-time monitoring of a dehydration of poly(vinyl alcohol) (PVA) film is researched. The technique based on the incorporation plasmonic nanocages (NCs) between the two identical layers of PVA, (PVA)/NCs/(PVA) film, and its sensitivity to the variation of the refractive index of the surrounding PVA film via desorption water. The dehydration time increases from 180 (s) to 1800 (s) as the content of the PVA in the films increases twice, from (PVA)/NCs/(PVA) to (PVA)2/NCs/(PVA)2. Such effect could be explained by different rate of the molecules desorption from the PVA based films. Specifically, the dehydration rate is of 0.22 (vol% per s) and 0.026 (vol% per s) for (PVA)/NCs/(PVA) and (PVA)2/NCs/(PVA)2 films, respectively. The dehydration rate constant reduces from -50×10-4 (s-1) to -4.3 ×10-4 (s-1) as the content of PVA increases from (PVA)/NCs/(PVA) to (PVA)2/NCs/(PVA)2 films, respectively.

scholarly journals Microwave-Assisted Synthesis of Chitosan/Polyvinyl Alcohol Silver Nanoparticles Gel for Wound Dressing Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Nguyen Thi Hiep ◽  
Huynh Chan Khon ◽  
Vo Van Thanh Niem ◽  
Vo Van Toi ◽  
Tran Ngoc Quyen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Microwave Irradiation ◽  
Polyvinyl Alcohol ◽  
Silver Ions ◽  
Diffusion Method ◽  
Poly Vinyl Alcohol ◽  
Microwave Assisted Synthesis ◽  
Vis Spectroscopy

The purpose of this study was to fabricate chitosan/poly(vinyl alcohol)/Ag nanoparticles (CPA) gels with microwave-assistance for skin applications. Microwave irradiation was employed to reduce silver ions to silver nanoparticles and to crosslink chitosan (CS) with polyvinyl alcohol (PVA). The presence of silver nanoparticles in CPA gels matrix was examined using UV-Vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The interaction of CS and PVA was analysed by Fourier transform infrared spectroscopy. The release of silver ions was determined by atomic absorption spectrometry. The antimicrobial properties of CPA gels againstP. aeruginosaandS. aureuswere investigated using agar diffusion method. Finally, the biocompatibility and wound-healing ability of the gels were studied using fibroblast cells (in vitro) and mice models (in vivo). In conclusion, the results showed that CPA gels were successfully fabricated using microwave irradiation method. These gels can be applied to heal an open wound thanks to their antibacterial activity and biocompatibility.

scholarly journals Effect of Anionic Surfactant on the Thermo Acoustical Properties of Sodium Dodecyl Sulphate in Polyvinyl Alcohol Solution by Ultrasonic Method

2011 ◽  
Vol 8 (1) ◽  
pp. 77-84 ◽  
Author(s):  
S. Ravichandran ◽  
C. Rathika Thaya Kumari
Keyword(s):  
Polyvinyl Alcohol ◽  
Ultrasonic Velocity ◽  
Sodium Dodecyl Sulphate ◽  
Ultrasonic Method ◽  
Sodium Dodecyl ◽  
Adiabatic Compressibility ◽  
Ultrasonic Waves ◽  
Poly Vinyl Alcohol ◽  
Acoustical Properties ◽  
Polymer Surfactant

The interaction of sodium dodecyl sulphate (SDS) / poly(vinyl alcohol) (PVA) solution was studied by ultrasonic velocity measurements. Ultrasonic velocity, density, viscosity in mixtures of sodium dodecyl sulphate in polyvinyl alcohol was measured over the entire range of composition. From the experimental data, other related thermodynamic parameters,viz., adiabatic compressibility, intermolecular free length, surface tension, relative association, relaxation time, absorption coefficient and internal pressure were calculated. Formations of rods interfere with velocity of ultrasonic waves. Hence the ultrasonic velocity decreases with concentration. These results were interpreted in terms of polymer-surfactant complex reactions.

Research Development of Biodegradable Modification of Poly (vinyl alcohol) Film

2011 ◽  
Vol 380 ◽  
pp. 234-237
Author(s):  
Yu Bin Lv ◽  
Quan Xiao Liu ◽  
Wen Cai Xu ◽  
Jin Li Li
Keyword(s):  
Polyvinyl Alcohol ◽  
Vinyl Alcohol ◽  
Degradation Rate ◽  
Degradation Process ◽  
Poly Vinyl Alcohol ◽  
Film Material ◽  
Research Development ◽  
Biodegradable Films ◽  
Film Properties ◽  
Biodegradable Film

Polyvinyl alcohol (PVA) is a kind of biodegradable film material, and its degradation process is mainly done through PVA-degrading enzymes, but the film biodegradation cycle is longer, so it needs other polymers with favorable biodegradability to improve the degradation rate in the nature environment. In this paper the biodegradation mechanism of PVA films and the influence of structural feature on biodegradability were described. The research development of starch-based biodegradable PVA films by blending starch to reduce the biodegradation cycle was emphasized and the biodegradable films modified by chitosan to improve film properties was briefly described.

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