scholarly journals Electrospinning of poly(methyl methacrylate) nanofibers in a pump-free process

2013 ◽  
Vol 33 (5) ◽  
pp. 453-461 ◽  
Author(s):  
Jasbir S. Bedi ◽  
Daniel W. Lester ◽  
Yuan X. Fang ◽  
John F.C. Turner ◽  
John Zhou ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Fiber Diameter ◽  
Solution Concentration ◽  
Prolate Spheroid ◽  
Nozzle Diameter ◽  
Solution Viscosity ◽  
Diameter Distribution ◽  
Poly Methyl Methacrylate ◽  
Voltage Bias ◽  
Free Process

Abstract The effects of processing parameters, including solution concentration, viscosity, nozzle diameter, voltage bias and the nozzle to collector distance, on the morphology and diameters of poly(methyl methacrylate) (PMMA) fibers have been systematically investigated, using a unique pump-free electrospinning method. For PMMA solution concentrations less than the critical entanglement concentration, ce, prolate spheroid-shaped droplets or beads with fibers were formed, whereas at concentrations above ce, good quality bead-free fibers were formed. Quantitative analysis revealed a linear dependence between the solution viscosity and fiber diameter. Larger fiber diameters were achieved by increasing the nozzle diameter and voltage bias. Increasing the bias voltage has the additional effect of broadening the diameter distribution, as a result of splaying and splitting. By contrast, when the strength of the electrical field was reduced by increasing the distance between the nozzle and collector, the overall fiber diameter was reduced.

scholarly journals Processing parameters for electrospinning poly(methyl methacrylate) (PMMA)/titanium isopropoxide composite in a pump-free setup

2018 ◽  
Vol 1 ◽  
pp. 27
Author(s):  
Leah Nyangasi ◽  
Dickson Andala ◽  
Charles Onindo ◽  
Alphonse Wanyonyi ◽  
Josphine Chepngetich
Keyword(s):  
Methyl Methacrylate ◽  
Polymer Solution ◽  
Solution Concentration ◽  
Titanium Isopropoxide ◽  
Processing Parameters ◽  
Solution Viscosity ◽  
Poly Methyl Methacrylate ◽  
Size And Morphology ◽  
Set Up ◽  
Almost All

Background: Electrospinning is a technique for producing nanofibers, useful in many fields of nanotechnology. The size and morphology of the nanofibers obtained depends on the polymer solution properties, the parameters of the equipment and the conditions of the surrounding. In almost all reported electrospinning set ups, a pump ,which regulates the flow of the polymer solution, has been included as one of the requirements. In this study, the effects of solution concentration, viscosity, voltage and the distance from the tip of the syringe to the aluminum collector on the morphology and diameters of poly(methyl methacrylate)(PMMA) fibers were investigated, using a pump-free electrospinning set up. Methods: Varied PMMA concentration (50 -120 mg/mL), voltage (10-18 kV) and distance (5 – 18 cm) of electrospinning were studied and the optimum electrospinning conditions identified.  PMMA/ titanium isopropoxide solution of ratio 1:2 was prepared, electrospun at optimized conditions (15 kV, 18 cm, Dichloromethane/Dimethylformamide 60:40) and the fibers obtained analyzed using a scanning electron microscope. Results: Solutions of PMMA whose concentrations were less than 50 mg/mL, produced beads on fibers, whereas those at ~ 100 mg/mL formed the best bead-free fibers of diameter 350±50 nm. The results showed a direct dependence of fiber diameter on the solution viscosity. Fibers of larger diameters were obtained when the distance from the tip of the syringe to the aluminum collector and voltage were increased but at higher distances (>18 kV) fewer fibers were collected. When the voltage was steadily increased, the fibers broadened and the diameters were non-uniform due to splaying and splitting. Increasing the distance between the pipette-tip and the collector from 10 to 18 cm resulted in reduced electric field which in turn yielded fewer fibers. Conclusions: The results obtained in a pump free set-up were comparable to those eletrospun in the presence of a pump.

scholarly journals Needleless Electrospinning of PA6 Fibers: The Effect of Solution Concentration and Electrospinning Voltage on Fiber Diameter

2020 ◽  
Vol 66 (7-8) ◽  
pp. 421-430
Author(s):  
Alexandra Aulova ◽  
Marko Bek ◽  
Leonid Kossovich ◽  
Igor Emri
Keyword(s):  
Electrical Conductivity ◽  
Surface Tension ◽  
Fiber Diameter ◽  
Polymer Concentration ◽  
Solution Concentration ◽  
Fine Tuning ◽  
Solution Viscosity ◽  
Diameter Distribution ◽  
Needleless Electrospinning ◽  
Pore Size Distributions

Needleless electrospinning is the process of forming thin material fibers from the open surface of its solution or melt in a strong electrostatic field. Electrospun non-woven materials are used in various applications that require specific fiber diameters and pore size distributions. Fiber diameter depends on the properties of the polymer solution and manufacturing conditions. A needleless electrospinning process using the Nanospider setup was investigated using the commonly used polyamide 6 (PA6) solution in a mixture of acetic and formic acids. Polymer solutions with different polymer concentrations were characterized by viscosity, surface tension and electrical conductivity. An increase in polymer content in the solution resulted in the exponential increase of the solution viscosity, polynomial increase of electrical conductivity and had almost no effect on surface tension. The effect of the polymer concentration in the solution, as well as electrospinning voltage on fiber diameter and diameter distribution, was investigated using scanning electron microscopy images. The average fiber diameter linearly increases with the increased polymer concentration and also demonstrates an increase with increased electrospinning voltage, although less pronounced. Therefore, a change in the PA6 solution concentration should be used for the robust adjustment of fiber diameter, while changes in electrospinning voltage are more appropriate for fine tuning the fiber diameter during the process of needleless electrospinning.

PROTON MAGNETIC RESONANCE LINE WIDTH AS A FUNCTION OF POLYMER TACTICITY

1966 ◽  
Vol 44 (2) ◽  
pp. 153-156 ◽  
Author(s):  
S. Brownstein ◽  
D. M. Wiles
Keyword(s):  
Magnetic Resonance ◽  
Methyl Methacrylate ◽  
Proton Magnetic Resonance ◽  
Chloroform Solution ◽  
Spin Coupling ◽  
Solution Viscosity ◽  
Dilute Solution ◽  
Poly Methyl Methacrylate ◽  
Resonance Line Width ◽  
Polymer Tacticity

The high resolution proton magnetic resonance spectra of five samples of poly(methyl methacrylate) in chloroform solution have been measured with 100 Mc/s equipment. The widths of the absorption lines arising from the protons of the α-methyl and the methoxyl groups have been compared. The widths are greater when the polymer is predominantly syndiotactic than when it is predominantly isotactic. It is concluded that isotactic samples have the more extended conformation in chloroform solution. An analogy with dilute solution viscosity measurements is outlined in support of this conclusion. Differences between the widths of the lines of the methylene protons in a completely isotactic poly(methyl methacrylate) sample are attributed to long range spin coupling.

Preparation and Characterization of Poly(Methyl Methacrylate) (PMMA) Fibers by Electrospinning

2019 ◽  
Vol 811 ◽  
pp. 163-169 ◽  
Author(s):  
Ervin Tri Suryandari ◽  
Muhammad Ali Zulfikar ◽  
Rino R. Mukti ◽  
Muhamad Nasir
Keyword(s):  
Methyl Methacrylate ◽  
Flow Rate ◽  
Supply Voltage ◽  
High Surface ◽  
Polymer Concentration ◽  
Diameter Distribution ◽  
Solution Flow Rate ◽  
Simple Method ◽  
Poly Methyl Methacrylate ◽  
Small Pore

Fibers are materials with advantageous properties such as lightweight material properties, has small pore size, and has high surface area, porosity,and permeability. An easy and simple method to prepare fibers is electrospinning. Using this method poly(methyl methacrylate) (PMMA) fibers were prepared. Several parameters include polymer concentration, solution flow rate, the distance of the nozzle tip to the collector, and the applied voltage were investigated to control the morphology, structure, and diameter of PMMA fibers. The Optimal electrospinning conditions for PMMA fibers production were a PMMA concentration is 8% (w/v), a power supply voltage is 20 kV, a distance of the tip of the nozzle to the ground collector is 15 cm, and a flow rate is 0.004 mL/min. The diameter distribution and morphology of the fibers were determined and characterized by Optical Microscopy and Scanning Electron Microscope (SEM), which showed that the produced fiber had an average diameter of 1.4925 µm, the contact angle of fiber PMMA is 125.307o and the spreading time of fibers PMMA is about 360 minutes

scholarly journals Evolution of Surface Morphology of Spin-Coated Poly(methyl methacrylate) Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2184
Author(s):  
Navid Chapman ◽  
Mingyu Chapman ◽  
William B. Euler
Keyword(s):  
Surface Morphology ◽  
Methyl Methacrylate ◽  
Spin Coating ◽  
Film Surface ◽  
Solution Concentration ◽  
Poly Methyl Methacrylate ◽  
Thin Film Surface ◽  
Aspect Ratios ◽  
Convective Instabilities ◽  
Rayleigh Benard

The morphology of sub-micron poly(methyl methacrylate) films coated to glass supports by spin coating from toluene is examined using surface profilometry. Wrinkled surfaces with local quasi-sinusoidal periodicity were seen on the surfaces of films with thicknesses of larger than 75 nm. The surface wrinkles had large aspect ratios with wavelengths in the tens of microns and amplitudes in the tens of nanometers. Wrinkles that formed during spin-coating are attributed to surface perturbations caused by Rayleigh–Bénard–Marangoni convective instabilities. The effects of film thickness, coating solution concentration, and drying rate on the thin film surface morphology are investigated. The results can be used to prepare surfaces with controlled morphology, either smooth or with periodic wrinkles.

scholarly journals The Effect of Flow Rate on Morphology and Deposition Area of Electrospun Nylon 6 Nanofiber

2012 ◽  
Vol 7 (4) ◽  
pp. 155892501200700 ◽  
Author(s):  
Shamim Zargham ◽  
Saeed Bazgir ◽  
Amir Tavakoli ◽  
Abo Saied Rashidi ◽  
Rogheih Damerchely
Keyword(s):  
Droplet Size ◽  
Flow Rate ◽  
Fiber Diameter ◽  
Electrospun Nanofibers ◽  
Solution Concentration ◽  
Nylon 6 ◽  
Taylor Cone ◽  
Diameter Distribution ◽  
Deposition Area ◽  
Fiber Diameter Distribution

Electrospinning is a process that produces continuous polymer fibers with diameters of a nanometric scale. Nylon 6 in formic acid was electrospun to obtain the nanofibers. Fibers with different diameters were obtained using flow rates of 0.1, 0.5, 1 and 1.5 mL/hr, 20 wt% solution concentration, with an applied voltage of 20 kV and 15 cm spinning distance. Flow rate influenced the fiber diameter distribution, droplet size and its initiating shape at the capillary tip, the trajectory of the jet, maintenance of Taylor cone, areal density and nanofiber morphology. The morphology of the electrospun nanofibers was analyzed by using the scanning electron microscope (SEM). The effect of flow rate on the deposition area was also investigated for better control of the process. It was observed that a stabilized Taylor cone, small average droplet size, narrowest fiber diameter distribution, more stability in the originating jet, and uniform morphology of nanofiber is obtained at a flow rate of 0.5 mL/hr.

scholarly journals Preparation of hydrophobic nanofibers by electrospinning of PMMA dissolved in 2-propanol and water

2019 ◽  
Vol 264 ◽  
pp. 03004 ◽  
Author(s):  
Hui-Yi Chang ◽  
Chao-Ching Chang ◽  
Liao-Ping Cheng
Keyword(s):  
Methyl Methacrylate ◽  
Room Temperature ◽  
Water Resistance ◽  
Environmentally Friendly ◽  
Solution Concentration ◽  
Contact Angles ◽  
Poly Methyl Methacrylate ◽  
Submicron Scale

In this study, we adopted rubbing alcohol (2-propanol/water = 7.8/2) as the solvent to prepare hydrophobic poly(methyl methacrylate) (PMMA) nanofibers (with submicron scale diameters) by electrospinning. In the literature, the general solvents, such as acetone, tetrahydrofuran, chloroform, toluene, etc., to dissolve PMMA are harmful and not environmentally friendly. 2-Propanol and water are both not hazardous to humans and the environment. PMMA dissolved in rubbing alcohol can be electrospun near room temperature. The solutions were heated at ~60 °C and allowed to cool to room temperature. Controlling the solution concentration and electrospinning parameters, fibers with diameters of 0.65~0.85 μm were obtained. The electrospun PMMA mats were hydrophobic with contact angles > 130 ° and showed good water resistance.

Preparation of Tetracycline Microparticles Based on Supercritical Fluid Technique

2011 ◽  
Vol 236-238 ◽  
pp. 1707-1711 ◽  
Author(s):  
Yan Jie Zhang ◽  
Xue Wu Liu ◽  
Yan Fang Yang ◽  
Zhi Zun Zhou
Keyword(s):  
Continuous Process ◽  
Solution Concentration ◽  
Nozzle Diameter ◽  
Nano Particles ◽  
Diameter Distribution ◽  
Micro Particles ◽  
Temperature Solution ◽  
Operation Parameters ◽  
Inhalation Administration ◽  
Narrow Diameter Distribution

Inhalation administration requests the microparticles with appropriate average diameters and narrow diameter distribution. In this paper, the tetracycline microparticles suitable for inhalation administration were prepared successfully by Supercritical anti-solvent (SAS) process developed in recent years. A continuous SAS process had been adopted to prepare the micro-particles of tetracycline using ethanol as solvent and supercritical CO2 as anti-solvent. The effects of pressure, temperature, solution concentration and nozzle diameter on the morphology, size and size distribution of the particles were investigated. The results showed that tetracycline micro-particles with diameters range of 20nm to 40nm could be obtained by SAS continuous process when ethanol was used as organic solvent at the experimental operation parameters of the pressure of 15MPa, the temperature of 35°C, the solution concentration of 5mg/ml and the nozzle diameter of 75µm. The nano-particles of tetracycline prepared by the above continuous SAS process can be used for alveolus targeting drug delivery and the preparation of sustained-releases micro-spheres

Characterization of Highly Branched Poly(methyl methacrylate) by Solution Viscosity and Viscoelastic Spectroscopy

2001 ◽  
Vol 34 (6) ◽  
pp. 1677-1684 ◽  
Author(s):  
Peter F. W. Simon ◽  
Axel H. E. Müller ◽  
Tadeusz Pakula
Keyword(s):  
Methyl Methacrylate ◽  
Solution Viscosity ◽  
Poly Methyl Methacrylate
Sign in / Sign up

Export Citation Format

Share Document