Effect of Applied Voltage on Polymer Aggregation in Electrospraying of Thermoplastic Polymer

2012 ◽  
Vol 535-537 ◽  
pp. 2522-2525 ◽  
Author(s):  
Amit Jadhav ◽  
Li Jing Wang ◽  
Rajiv Padhye
Keyword(s):  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Solution Concentration ◽  
Solution Flow Rate ◽  
Thermoplastic Polymer ◽  
Solution Flow ◽  
Polymer Liquids ◽  
Polymeric Solutions ◽  
Uniform Droplets

In an electrospraying process, the polymer solution interacts with the electric field. Charged polymeric solutions causing polymer liquids to move, break into drops or spray into fine droplets. Electrospraying has the ability to generate very small & uniform droplets of polymeric solution. It is envisaged that electrospraying is a promising technology to coat a polymer on surface at submicron range. The polymer aggregation is important while coating. The process parameters including applied voltage, nozzle-collector distance, solution flow rate, and solution concentration play an important role in polymer droplets aggregation on surface. This research paper investigates the effect of applied voltage on aggregation of polymer droplets.

Electrospinning of Polycaprolactone in Dichloromethane/Dimethylformamide Solvent System

2013 ◽  
Vol 849 ◽  
pp. 337-342 ◽  
Author(s):  
Narissara Kulpreechanan ◽  
Tanom Bunaprasert ◽  
Ratthapol Rangkupan
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Mixed Solvent ◽  
Solution Concentration ◽  
Solvent System ◽  
Fiber Formation ◽  
Solution Flow Rate ◽  
Fiber Morphology ◽  
Solution Flow ◽  
Fiber Size

Electrospinning of polycaprolactone (PCL) in a mixed solvent of dichloromethane (DCM)/dimethylformamide (DMF) with 1:1 volumetic mixing ratio was studied. The effects of solution concentration (5-30 %w/v), applied voltage (10-25 kV), solution flow rate (0.1-2.0 mL/h) and collecting distance (10, 20 cm) on fiber formation and morphology were investigated. The size of PCL fibers obtained were in the range of 10s nm-2.6 μm with either bead on string or smooth fiber morphology. In this study, the solution concentration strongly affected fiber size exponentially. The fiber size also increased with an increase in solution flow rate. The applied voltage and the collecting distance have no or minimal effect on PCL fiber size.

Effect of Field Strength on Polymer Aggregation in Electrohydrodynamic Spraying of Thermoplastic Polyurethane

2013 ◽  
Vol 328 ◽  
pp. 895-900 ◽  
Author(s):  
Amit Jadhav ◽  
Li Jing Wang ◽  
Rajiv Padhye
Keyword(s):  
Field Strength ◽  
Thermoplastic Polyurethane ◽  
Solution Concentration ◽  
Rate Of Change ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Polymeric Solution ◽  
Polymer Liquids ◽  
Uniform Droplets ◽  
Electrohydrodynamic Spraying

Polymer solution interacts with the electric field in an electrohydrodynamic (EHD) spraying process. Charged polymeric solution forces polymer liquids to move, break into spray of fine droplets. EHD spraying has the ability to generate very small & uniform droplets of polymeric solution. It is envisaged that EHD Spraying is a promising technology to coat a polymer on substrate at submicron range. The polymer aggregation is important while coating. The process parameters including applied voltage, nozzle-collector distance, solution flow rate, and solution concentration plays an important role in polymer droplets aggregation on surface. Field strength is also plays important role while EHD spraying. Field strength is the rate of change of potential with respect to distance. This research paper investigates the effect of field strength on aggregation of polymer droplets.

scholarly journals Neutralization Dialysis for Phenylalanine and Mineral Salt Separation. Simple Theory and Experiment

Membranes ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 171 ◽  
Author(s):  
Anton Kozmai ◽  
Elena Goleva ◽  
Vera Vasil’eva ◽  
Victor Nikonenko ◽  
Natalia Pismenskaya
Keyword(s):  
Amino Acid ◽  
Flow Rate ◽  
Solution Concentration ◽  
Exchange Capacity ◽  
Ion Concentration ◽  
Solution Flow Rate ◽  
Strong Electrolyte ◽  
Mineral Salts ◽  
Solution Flow ◽  
Hydrodynamic Mode

A simple non-steady state mathematical model is proposed for the process of purification of an amino acid solution from mineral salts by the method of neutralization dialysis (ND), carried out in a circulating hydrodynamic mode. The model takes into account the characteristics of membranes (thickness, exchange capacity and electric conductivity) and solution (concentration and components nature) as well as the solution flow rate in dialyzer compartments. In contrast to the known models, the new model considers a local change in the ion concentration in membranes and the adjacent diffusion layers. In addition, the model takes into consideration the ability of the amino acid to enter the protonation/deprotonation reactions. A comparison of the results of simulations with experimental data allows us to conclude that the model adequately describes the ND of a strong electrolyte (NaCl) and amino acid (phenylalanine) mixture solutions in the case where the diffusion ability of amino acids in membranes is much less, than mineral salts. An example shows the application of the model to predict the fluxes of salt ions through ion exchange membranes as well as pH of the desalination solution at a higher than in experiments flow rate of solutions in ND dialyzer compartments.

scholarly journals Comparative Study for Organic and Inorganic Draw Solutions in Forward Osmosis

2017 ◽  
Vol 13 (1) ◽  
pp. 94-102
Author(s):  
Ahmed Faiq Al-Alalawy ◽  
Talib Rashid Abbas ◽  
Hadeer Kadhim Mohammed
Keyword(s):  
Flow Rate ◽  
Water Flux ◽  
Forward Osmosis ◽  
Solution Concentration ◽  
Salt Flux ◽  
Effect Of Temperature ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Draw Solution ◽  
Reverse Salt Flux

The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell.  Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with respect to water flux. The results showed an increase in water flux with increasing feed temperature and draw solution concentrations In addition, the flux increased with increasing feed flow rate while the flux was inversely proportional with the draw solution flow rate. The results showed that reverse osmosis membranes (TFC and CA) are not suitable for using in FO process due to the relatively obtained low water flux when compared with the flux obtained by forward osmosis membrane (CTA). NaCl draw solution gave higher water flux than other draw solutions and at the same time, revealed higher reverse salt flux.

The Effect of Processing Parameters Onpoly (Lactic Acid)/Poly(Ethylene Oxide)Bicomponentultrafine Fibersby Co-Electrospinning

2013 ◽  
Vol 701 ◽  
pp. 254-258 ◽  
Author(s):  
Suttipan Pavasupree ◽  
Kawee Srikulkit ◽  
Ratthapol Rangkupan
Keyword(s):  
Lactic Acid ◽  
Flow Rate ◽  
Applied Voltage ◽  
Water Soluble ◽  
Flow Rate Ratio ◽  
Poly Lactic Acid ◽  
Solution Flow Rate ◽  
Electrospinning Technique ◽  
Solution Flow ◽  
Water Soluble Polymer

Poly (lactic acid) (PLA)/polyethylene oxide (PEO) bicomponent fibers werefabricated by co-electrospinning technique in a side by side configuration. Effect of PEO concentration, PLA and PEO solution flow rate and an applied voltage on formation, size and morphology of the fibers were investigated. The results showed that the fibers size increased with increasing PEO concentration, PEO flow rate ratio and applied voltage. The composition of the fibers was confirmed by IR spectrum. Additionally, by pairing PEO, which is a water soluble polymer, with PLA, follow by PEO phase removal in water, a C-shaped ultrafine fiber was prepared.

scholarly journals Electrospun Ocimum Sanctum Loaded Fibres With Potential Biomedical Applications – Periodontal Therapeutic Perspective

2018 ◽  
Vol 11 (3) ◽  
pp. 1731-1736 ◽  
Author(s):  
Priyanka Mariam George ◽  
Sheeja S Varghese
Keyword(s):  
Vinyl Acetate ◽  
Flow Rate ◽  
Applied Voltage ◽  
Cost Effective ◽  
Sem Analysis ◽  
Ocimum Sanctum ◽  
Solution Flow Rate ◽  
Sem Images ◽  
Solution Flow ◽  
Therapeutic Perspective

Electro spinning is a technique that is simple, unique, cost effective and versatile. The nanofibers obtained are to be non woven with high tunable porosity and a large surface area. The parameters decide the morphology of the resultant fibers, such as tip to collector distance, viscosity of the solution, diameter of the needle. By controlling or tuning the parameters it is possible to obtain or fabricate fibers for the desired function. To establish ideal spinning parameters so as to formulate a nanoscale resorbable system for local periodontal therapy based on electro spinning of Ocimum sanctum(Tulsi) loaded resorbable Poly vinyl acetate (PVA) fibers. Ocimum sanctum (Tulsi) extract prepared was incorporated by electro spinning (HOLAMRC’S HO-SPLF4) into Poly vinyl acetate (PVA) at different concentrations (1-20%w/w). Electrospinning was performed at different paremeters: applied voltage of 13,15,20,55Kv.Tip- to- collector distance was set at 12, 22, 16-18.5cm .solution flow rate was 500µl/hr0.8ml/hr,1ml/hr,1.5ml/hr, tip diameter was 12mm,22m,0.91mm,.4mm. volume of the solutions were 2.5, 1ml, duration was of 5 or 3 hours. The fibers obtained were subjected to SEM analysis. Electro spinning of 10% concentration tulsi done under the following conditions resulted in formation of uniform and beadless fibers. Applied voltage of 13kV, tip- to- collector distance at 12cm, solution flow rate of 500µl/hr, tip diameter of 12mm, volume of 2.5ml and duration of 5hrs. SEM images revealed that the textures of all resultant samples were homogenous and free of heterogeneities or artefacts’ The study revealed that Ocimum sanctum (Tulsi) 10wt% incorporated into PVA can be electrospun into nonfibers at an applied voltage of 13kV, tip- to- collector distance of 12cm, solution flow rate at 500µl/hr, and a tip diameter of 12mm.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Effect of Tin Oxide Coatings by Spray Pyrolysis Process on Mechanical Properties of Aluminium, Brass and Mild Steel

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
M. Shunmugasundaram ◽  
A. Praveenkumar ◽  
L. Ponraj Sankar ◽  
S. Sivasankar
Keyword(s):  
Mechanical Properties ◽  
Mild Steel ◽  
Substrate Temperature ◽  
Spray Pyrolysis ◽  
Tin Oxide ◽  
Microstructural Analysis ◽  
Solution Concentration ◽  
Solution Flow Rate ◽  
Spray Pyrolysis Method ◽  
Solution Flow

Mechanical properties of materials are enhanced by different methods to increase the usage of the materials. In this research spray pyrolysis method is employed to increase the mechanical characteristics of three different materials. The tin oxide is chosen as coated material and aluminium, brass, mild steel are selected as substrate materials. The 500nm thin film is developed over the substrate materials by spray pyrolysis. The substrate temperature are chosen as 300? C for aluminium, 400? C for brass and mildsteel. Nozzle to substrate distance is 0.4 m, substrate temperature is 300? C for aluminium and 400? C for solution concentration as 0.2 mole and solution flow rate is 1ml/min are selected for constant deposition parameters. The hardness and tensile strength result clearly shows that strength is increased by adding the coating over the surface. The material is heated above crystallization temperature and SnO2 increases the tensile and hardness strength of the materials. The triangular metrological microscope is used to examine the microstructure of non coated and coated substrate materials. The microstructural analysis is showed that the uncoated surface of the substrate material is full of rough and pores. And displays that the tin oxide coated surface of the substrates after the initial deposition disclosed a surface with a agglomeration of tin oxide in homogeneous and uniform than the uncoated substrates.

scholarly journals Pellet Softening Process for the Removal of the Groundwater Hardness; Modelling and Experimentation

2019 ◽  
Vol 12 (3) ◽  
pp. 135-143 ◽  
Author(s):  
Fatin Abdul_kareem Ashoor ◽  
Amer D. Zmat ◽  
Muthanna H. AlDahhan
Keyword(s):  
Calcium Carbonate ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Solution Flow Rate ◽  
Pellet Size ◽  
Solution Flow ◽  
Bed Height ◽  
Naoh Solution ◽  
Softening Process ◽  
Calcium And Magnesium Ions

A lab scale pellet reactor (PR) was designed and fabricated to carry out extensive investigations on the removal efficiency of the hardness of groundwater.  The groundwater of 2200 – 2600 mg/L hardness was collected from Abdulla Ibnalhassan wells area located at the west desert of Al-Shinafiyah district (70 km to the southwest of Al-Dewaniyah city, Iraq). Both hydrodynamic parameters of the pellet reactor (porosity and fluidized bed height) and the parameters of calcium carbonate crystallization process (calcium carbonate equilibrium, pellet size, and density) were modeled and compared with the experimental results of the lab scale pellet reactor. The comparison showed that fair agreement between modeled and measured results was observed. The removal efficiency of both calcium and magnesium ions were 62.5-99% and 83-99% respectively. The removal efficiency was found to be strongly dependent on pH and the ratio of NaOH solution flow rate to the groundwater flow rate in the pellet reactor.

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