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 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.

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.

scholarly journals Gel electrolytes based on poly(vinylidenefluoride-co-hexafluoropropylene)/thermoplastic polyurethane/poly(methyl methacrylate) with in situ SiO2 for polymer lithium batteries

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3240-3248 ◽  
Author(s):  
Zeyue He ◽  
Qi Cao ◽  
Bo Jing ◽  
Xianyou Wang ◽  
Yuanyuan Deng
Keyword(s):  
Methyl Methacrylate ◽  
Polymer Solution ◽  
Polymer Electrolyte ◽  
Lithium Batteries ◽  
Room Temperature ◽  
Thermoplastic Polyurethane ◽  
Gel Polymer Electrolyte ◽  
Poly Methyl Methacrylate ◽  
Gel Electrolytes

Gel polymer electrolyte films based on poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF–HFP), thermoplastic polyurethane (TPU) and poly(methyl methacrylate) (PMMA) with and without in situ SiO2 fillers are prepared by electrospinning polymer solution at room temperature.

Effects of Processing Parameters on the Morphology and Size of Electrospun PHBV Micro- and Nano-Fibers

2007 ◽  
Vol 334-335 ◽  
pp. 1233-1236 ◽  
Author(s):  
Ho Wang Tong ◽  
Min Wang
Keyword(s):  
Tissue Engineering ◽  
Polymer Solution ◽  
Polymer Concentration ◽  
Solution Concentration ◽  
Processing Parameters ◽  
Electrospun Fibers ◽  
Effective Technique ◽  
Electrospinning Technique ◽  
Needle Diameter ◽  
Short Time

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was used to fabricate micro- and nano-fibrous, non-woven mats by electrospinning for potential tissue engineering applications. The morphology and size of electrospun fibers were assessed systematically by varying the processing parameters. It was found that the diameter of the fibers produced generally increased with electrospinning voltage, needle diameter for the polymer jet and polymer solution concentration. Beaded fibers were readily produced at low PHBV concentrations, whereas the needle was blocked within a very short time during electrospinning when the PHBV concentration was too high. At the polymer concentration of 7.5 % w/v, it was shown that beadless PHBV fibers could be generated continuously by adjusting the electrospinning parameters to appropriate values. This study has clearly demonstrated that electrospinning can be an effective technique to produce PHBV micro- and nano-fibers. It has also been shown that composite fibers containing hydroxyapatite (HA) can be produced using the electrospinning technique.

Micro/Nanofabrication by Spin Dewetting on a Poly(Dimethylsiloxane) Mold

2007 ◽  
Vol 1002 ◽  
Author(s):  
Nicholas Ferrell ◽  
Aimee Bross ◽  
Derek Hansford
Keyword(s):  
Aqueous Solution ◽  
Methyl Methacrylate ◽  
Polymer Solution ◽  
Spin Coating ◽  
Solution Concentration ◽  
Tetramethylammonium Hydroxide ◽  
Pdms Mold ◽  
Feature Size ◽  
Propyl Methacrylate ◽  
Glass Substrates

ABSTRACTThe process of spin dewetting was used to fabricate polymer micro and nanostructures from poly(methyl methacrylate) (PMMA), poly (propyl methacrylate) (PPMA), and polystyrene (PS). Polymer structures were formed on poly(dimethylsiloxane) (PDMS) molds by dewetting of a polymer solution during spin coating. Features were removed from the mold using heat and pressure to transfer the polymer to silicon or glass substrates. By varying the coating conditions, a variety of different polymer feature morphologies were obtained for a given PDMS mold geometry. In this study, the ability to fabrication polymer micro and nanostructures using spin dewetting was demonstrated on a variety of PDMS mold geometries. The effects of polymer solution concentration and mold feature size on the resulting polymer structures were examined. In addition, microfabricated PMMA structures were used as etch masks for anisotropic etching of silicon in an aqueous solution of tetramethylammonium hydroxide (TMAH).

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 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.

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
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