scholarly journals Comparative analysis of superabsorbent properties of PVP and PAA nanofibres

2021 ◽  
Vol 72 (04) ◽  
pp. 460-466
Author(s):  
BUKET GÜLER ◽  
FUNDA CENGİZ ÇALLIOĞLU
Keyword(s):  
Surface Tension ◽  
Comparative Analysis ◽  
Fibre Diameter ◽  
Volume Ratio ◽  
High Specific Surface Area ◽  
Absorption Capacity ◽  
Solution Viscosity ◽  
Optimum Process ◽  
Absorption Properties ◽  
Synthetic Urine

This study presents the comparative analysis of production, characterization and absorption properties of Polyvinylpyrrolidone (PVP) and Polyacrylic acid (PAA) nanofibres. Firstly, optimization studies about polymer (PVP and PAA), superabsorbent additive (waterlock)(WL) and crosslinker agent (sodium persulfate and glutaraldehyde)concentrations were achieved. Then solution properties such as conductivity, surface tension and viscosity were determined. Electrospinning was carried out under the optimum process parameters (voltage, distance between the electrodes, solution feed rate etc.) to obtain superabsorbent nanofibrous surfaces. Surface and fibre morphologies were analysed with Scanning Electron Microscopy (SEM) and thickness of nanoweb and weight in grams of nanofibres were also measured. Lastly, optimized PVP and PAA nanofibres were compared in terms of absorption properties with water and synthetic urine with various times from 5 to 86400 seconds. According to the results, generally fine, smooth and uniform nanofibres were obtained. It was observed that the solution viscosity, conductivity, and average fibre diameter increase with waterlock (WL) and cross-linker additions while surface tension was not change. In addition, PAA nanofibres’ absorption capacity with water and synthetic urine was higher than PVP nanofibres, while PVP nanofibres’ absorption rate is higher. It is possible to say that electrospun nanofibrous surfaces that are ultra-thin, light, porous and with high specific surface area to volume ratio are promising for new superabsorbent materials.

scholarly journals ELECTROSPINNING OF ANTIBACTERIAL POLYURETHANE/ZnO NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 185-192
Author(s):  
İ.Y. Mol ◽  
F.C. Çallioğlu
Keyword(s):  
Surface Tension ◽  
Antibacterial Activity ◽  
Water Vapour ◽  
Fibre Diameter ◽  
Water Vapour Permeability ◽  
Solution Viscosity ◽  
Optimum Process ◽  
Solution Properties ◽  
Vapour Permeability ◽  
Zno Nanofibers

In this study, it is aimed to produce and characterize antibacterial polyurethane (PU)/Zinc oxide (ZnO) nanofibers by electrospinning method. Firstly, polymer solutions were prepared at various ZnO concentrations such as 0, 0.2, 0.4, 0.6, 0.8, 1. Then solution properties (conductivity, viscosity, surface tension) were determined and analysed the effects of ZnO concentration on the solution properties. PU/ZnO nanofibers produced via electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate and atmospheric conditions). Finally, the nanofibers were characterized in terms of fibre morphology, thermal stability, permeability and antibacterial activity using SEM-EDS, DSC-TGA, water vapour permeability and disk diffusion methods. According to the solution results; it was observed that conductivity and surface tension decrease significantly with ZnO addition. On the other hand, solution viscosity increases as the ZnO concentration increases. From the SEM images, it has been seen clearly that average fibre diameter increases with ZnO concentration and incorporation of ZnO particles to the fibre structure was verified by SEM-EDS. According to the thermal analyse result, nanofibers begin to degrade between 271.94 ºC and 298.73 ºC. In addition, water vapour permeability increases as the ZnO concentration increase. Lastly antibacterial activity against gram negative (E.coli) and gram positive (S. aureus) was determined with specific zone diameter.

scholarly journals EMULSION ELECTROSPINNING OF POLYVINYLPYRROLIDONE (PVP)/PARACETAMOL NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 193-199
Author(s):  
M. Geysoğlu ◽  
H.K. Güler ◽  
F.C. Çallıoğlu ◽  
İ.Y. Mol
Keyword(s):  
Surface Tension ◽  
Fibre Diameter ◽  
Optimum Process ◽  
Atmospheric Conditions ◽  
Sem Images ◽  
Water Emulsion ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
Ft Ir ◽  
Oil In Water Emulsion

This study aimed to achieve Polyvinylpyrrolidone (PVP) nanofiber production including paracetamol (PCT) by oil-in-water emulsion electrospinning. At first, emulsions were prepared at 14 wt % PVP with various PCT concentrations (0, 0.1, 0.3, 0.5, 0.7, 0.9 wt %). Then, solution properties such as viscosity, conductivity, and surface tension were determined. The production of nanofiber samples was carried out by emulsion electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate, and atmospheric conditions). Finally, the morphological and structural characterization of the nanofiber surface was carried out with SEM and FT-IR. According to the results of emulsion properties, although the change is not remarkable, it tends to increase the viscosity with an increase in PCT concentration. On the other hand, it was observed that surface tension did not change significantly with PCT concentration increasement and while the conductivity of emulsions decreased slightly. When the fibre structure was investigated, average fibre diameter and fibre diameter uniformity were not affected prominently by PCT concentration. From the SEM images, it is possible to say that generally fine, uniform and bead-free drug-loaded nanofibers were obtained. The finest (326 nm) and most uniform (1.03) nanofibers were achieved from the sample N4 which included 0.5 wt % PCT. Also, the FT-IR results verified that PVP and PCT exist in the nanofiber structure.

scholarly journals SOLVENT OPTIMIZATION OF ELECTROSPUN POLY(ACRYLIC ACID) NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 178-184
Author(s):  
M. Geysoğlu ◽  
F.C. Çallıoğlu
Keyword(s):  
Surface Tension ◽  
Acrylic Acid ◽  
Ph Value ◽  
Fibre Diameter ◽  
Optimum Process ◽  
Distilled Water ◽  
Solution Properties ◽  
Atmospheric Conditions ◽  
Fibre Morphology ◽  
Poly Acrylic Acid

In this study, it was investigated experimentally the influence of various solvents (distilled water and ethanol) on the solution properties, spinning performance, and fibre morphology of the electro spun Poly (acrylic acid) nanofibers. Firstly, polymer solutions were prepared at 5 wt % PAA with various solvent ratios of ethanol and distilled water. Then, solution properties such as viscosity, density, pH, conductivity, and surface tension were determined. The production of nanofiber samples was carried out by electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate, and atmospheric conditions). Finally, the morphological characterization of the nanofiber surface was carried out with SEM. According to the results, it was observed that conductivity, surface tension and the density of the solution increase as the ethanol ratio decreases. On the other hand, pH value increases as the ethanol ratio increases and, so, the acidic value of the solutions decreases. The viscosity increased until the ethanol/distilled water ratio was 50/50 and then decreased as the ethanol percentage decreased to under 50%. In addition, average fibre diameter decreases with ethanol ratio decreases. It is possible to say that solvent type affects solution properties, fibre morphology and spinning performance significantly. Generally, fine, uniform and bead free nanofibers could be electro spun and the PAA solution containing 70 wt % distilled water and 30 wt % ethanol was selected as the optimum in terms of fibre morphology, web quality and spinning performance.

scholarly journals PARACETAMOL DRUG LOADED MICROCAPSULE BASED NANOFIBER PRODUCTION

2021 ◽  
Vol 2021 ◽  
pp. 200-207
Author(s):  
İ.Y. Mol ◽  
F.C. Çallıoğlu ◽  
H.K. Güler ◽  
M. Geysoğlu
Keyword(s):  
Surface Tension ◽  
Fibre Diameter ◽  
Controlled Drug Release ◽  
Electrospinning Process ◽  
Core Material ◽  
Optimum Process ◽  
Sem Images ◽  
Eudragit Rs ◽  
Uniformity Coefficient ◽  
Average Fibre Diameter

In this study, it was aimed to production and characterization of paracetamol (PCT) loaded microcapsules and microcapsule added electro spun PVA nanofibers. Eudragit RS 100 and PVA were used as the shell in the microcapsule structure, and PCT was used as the core material. First of all, the PCT loaded Eudragit RS 100/PVA microcapsules were produced by solvent evaporation method under the optimum process parameters. Then, properties such as conductivity, viscosity and surface tension of the microcapsule loaded PVA solution were measured and the effects of microcapsule concentration on the solution properties were determined. According to the solution results, while the viscosity increased with the microcapsule concentration, conductivity and surface tension did not change significantly except for the PVA-10 sample. After the electrospinning process, fibre morphology was determined by SEM and incorporation of microcapsules into the nanofibers was clearly demonstrated. It was calculated from the SEM images that average microcapsule size is 9.81μm, average fibre diameter is 550 nm and fibre diameter uniformity coefficient is 1.025. Finally, the incorporation of PCT loaded microcapsules into the nanofibers was chemically confirmed by FT-IR analysis. It is thought that the results of this study will be useful for controlled drug release, especially in medical textiles.

Optimization of Process Parameters for Production of Pectinase using Bacillus Subtilis MF447840.1

2019 ◽  
Vol 13 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Ram Balak Mahto ◽  
Mukesh Yadav ◽  
Soumya Sasmal ◽  
Biswnath Bhunia
Keyword(s):  
Bacillus Subtilis ◽  
Process Parameters ◽  
Volume Ratio ◽  
Optimum Process ◽  
Agitation Rate ◽  
Fermentation Condition ◽  
Optimization Of Process Parameters ◽  
Food And Beverage ◽  
Pectinase Production ◽  
Sterile Product

Background: Pectinase enzyme has immense industrial prospects in the food and beverage industries. </P><P> Objective: In our investigation, we find out the optimum process parameters suitable for better pectinase generation by Bacillus subtilis MF447840.1 using submerged fermentation. </P><P> Method: 2% (OD600 nm = 0.2) of pure Bacillus subtilis MF447840.1 bacterial culture was inoculated in sterile product production media. The production media components used for this study were 1 g/l of pectin, 2 g/l of (NH4)2SO4, 1 g/l of NaCl, 0.25 g/l of K2HPO4, 0.25 g/l of KH2PO4 and 1 g/l of MgSO4 for pectinase generation. We reviewed all recent patents on pectinase production and utilization. The various process parameters were observed by changing one variable time method. </P><P> Results: The optimum fermentation condition of different parameters was noticed to be 5% inoculums, 25% volume ratio, temperature (37°C), pH (7.4) and agitation rate (120 rpm) following 4 days incubation. </P><P> Conclusion: Maximum pectinase generation was noticed as 345 ± 12.35 U following 4 days incubation.

scholarly journals Cellulose Nanofibrils/Xyloglucan Bio-Based Aerogels with Shape Recovery

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Samuel Mandin ◽  
Samuel Moreau ◽  
Malika Talantikite ◽  
Bruno Novalès ◽  
Jean-Eudes Maigret ◽  
...  
Keyword(s):  
Water Absorption ◽  
Shape Recovery ◽  
Cellulose Nanofibrils ◽  
High Water ◽  
Absorption Capacity ◽  
Absorption Properties ◽  
High Affinity ◽  
High Water Absorption ◽  
Freezing Procedure ◽  
The Impact

Bio-based aerogels containing cellulose nanofibrils (CNFs) are promising materials due to the inherent physical properties of CNF. The high affinity of cellulose to plant hemicelluloses (xyloglucan, xylan, pectin) is also an opportunity to develop biomaterials with new properties. Here, we prepared aerogels from gelled dispersions of CNFs and xyloglucan (XG) at different ratios by using a freeze-casting procedure in unidirectional (UD) and non-directional (ND) manners. As showed by rheology analysis, CNF and CNF/XG dispersions behave as true gels. We investigated the impact of the freezing procedure and the gel’s composition on the microstructure and the water absorption properties. The introduction of XG greatly affects the microstructure of the aerogel from lamellar to cellular morphology. Bio-based aerogels showed high water absorption capacity with shape recovery after compression. The relation between morphology and aerogel compositions is discussed.

scholarly journals Influence of nanoparticles on the morphology, thermal stability and air permeability of electrospun polylactic-acid fibres

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Jenny Alongi ◽  
Merima Pošković
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Polylactic Acid ◽  
Polymer Matrix ◽  
Fibre Diameter ◽  
Air Permeability ◽  
Solution Viscosity ◽  
Polymer Molecular Weight ◽  
Neat Polymer ◽  
Lower Permeability

AbstractPolylactic-acid (PLA) and PLA-clay fibres have been produced from solution of 1,1,1,3,3,3-hexafluoro-2-propanol by electrospinning. Nanoclays having different aspect ratio, namely a montmorillonite and a sepiolite, have been added and dispersed within the polymer matrix in order to enhance the thermal stability and air permeability of PLA. The influence of the polymer molecular weight, the solution viscosity and conductivity on the morphology of the fibres has been investigated. Electron microscopy has shown that fibre diameter and the presence of beads defects in the fibres depend on the type of clay added to the polymer matrix. The thermal stability in nitrogen and in air has been drastically enhanced for the presence of the clays as compared with neat polymer. Finally, permeability tests performed on the electrospun condensed fibres pointed out that PLA-clay fibres exhibit a lower permeability to air (up to 90%) with respect to neat PLA fibres.

Electrospun nanofibre materials to filter air pollutants – A review

2016 ◽  
Vol 47 (8) ◽  
pp. 2253-2280 ◽  
Author(s):  
Vinod V Kadam ◽  
Lijing Wang ◽  
Rajiv Padhye
Keyword(s):  
Particulate Matter ◽  
Air Pollutants ◽  
Fibre Diameter ◽  
Active Surface ◽  
High Specific Surface Area ◽  
Gaseous Pollutants ◽  
Air Filtration ◽  
Small Fibre ◽  
Small Pore ◽  
Characteristic Features

This review presents an overview of electrospun nanomembranes produced from various polymers to filter air pollutants. Air pollutants can be categorised as particulate matter and gaseous pollutants. Both differ from each other in terms of size and chemical composition. Hence, the filter characterisation techniques and capture mechanism also vary. Particulate matter can be effectively captured in nanomembranes, in relation to microfibres, due to its small fibre diameter, small pore size and high specific surface area. Recently, electrospun nanomembranes have been used to filter gaseous pollutants owing to their potential of active surface modification. Different additives which functionalised the nanofibre surface for gaseous pollutant adsorption are also highlighted in this review. The characteristic features of nanofibres influencing the filtration efficiency have been discussed. Furthermore, various research challenges and future trends of electrospun nanomembranes in air filtration have been discussed.

Steel Slag as a Substitute for Natural Aggregate in the Production of Concrete

2015 ◽  
Vol 244 ◽  
pp. 77-87 ◽  
Author(s):  
Vojtěch Václavík ◽  
Tomáš Dvorský ◽  
Vojtěch Šimíček ◽  
Marcela Ondová ◽  
Jan Valíček ◽  
...  
Keyword(s):  
Experimental Research ◽  
Steel Slag ◽  
Volume Ratio ◽  
Shape Index ◽  
Specific Weight ◽  
Strength Properties ◽  
Absorption Capacity ◽  
Concrete Mixture ◽  
Powder Density ◽  
Natural Aggregates

This article presents the results of an experimental research dealing with the use of steel slag as a partial substitute for natural aggregates in the production of concrete composite. Comparative mixture based on natural aggregates was prepared from the fractions of 0/4, 4/8 and 8/16 mm, which were represented in the volume ratio of 40:30:30. During the experimental research, natural aggregates with the fractions of 4/8 mm, 8/16 mm were replaced with steel slag of the same faction. We have tested the input properties of natural aggregates and steel slag for the designed experimental mixtures (grain size, density, specific weight, powder density, absorption capacity, resistance to crushing, shape index). In case of concrete mixture prepared according to the experimental recipes, we have monitored the following characteristics: density of fresh concrete mixture, consistency of concrete mixture, strength characteristics - cube strength after 3, 7, 14, 21, 28 and 90 days, prism strength after 28 days. The research has discovered that substitution of natural aggregates with steel slag of the same fraction in concrete mixture is possible, without significantly affecting the strength properties of the concrete based on steel slag in comparison with the concrete based on natural aggregates.

Fabrication of Copolymer PMMA-BMA Oil Absorption Resin

2016 ◽  
Vol 848 ◽  
pp. 120-124
Author(s):  
Lei Chen ◽  
Yu Fei Tang ◽  
Xu Liu ◽  
Kang Zhao
Keyword(s):  
Porous Material ◽  
Dispersion Polymerization ◽  
Retention Rate ◽  
Crosslinking Agent ◽  
Absorption Capacity ◽  
Oil Absorption ◽  
Absorption Properties ◽  
Oil Retention ◽  
Monomer Ratio ◽  
Polyurethane Sponge

PMMA-BMA oil absorption resin was prepared by dispersion polymerization. Oil absorption properties were adjusted by changing the monomer ratio, content of initiator and crosslinking agent. Absorption capacity of porous material, which PMMA-BMA oil absorption resin adhesive in the polyurethane surface, was also investigated. The experimental results show that the best oil absorption ratio of PMMA-BMA copolymer resin was obtained when the MMA/BMA mole ratio was1:1.5, and the initiator and crosslinking agent was 0.4% and 0.35% of the copolymer resin respectively. The porous material was fabricated using the porous polyurethane sponge dipped in the liquid copolymer resin. The porous material resin can be reused since its low oil retention rate, and it can be used as absorption container of oil vapor.

Sign in / Sign up

Export Citation Format

Share Document