Preparation of electrospun nanocomposite nanofibers of polyaniline/poly(methyl methacrylate) with amino-functionalized graphene

In this paper we report upon the preparation and characterization of electrospun nanofibers of doped polyaniline (PANI)/poly(methyl methacrylate) (PMMA)/amino-functionalized graphene (Am-rGO) by electrospinning technique. The successful functionalization of rGO with amino groups is examined by Fourier transforms infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and Raman microspectrometer. The strong electric field enables the liquid jet to be ejected faster and also contributes to the improved thermal and morphological homogeneity of PANI/PMMA/Am-rGO. This results in a decrease in the average diameter of the produced fibers and shows that these fibers can find promising uses in many applications such as sensors, flexible electronics, etc

Combined effect of ultrasound stimulations and autoclaving on the enhancement of antibacterial activity of ZnO and SiO₂/ZnO nanoparticles

This study investigates the antibacterial activity (ABA) of suspensions of pure ZnO nanoparticles (ZnO-NPs) and mesoporous silica doped with ZnO (ZnO-UVM7), as well as electrospun nanofibers containing those nanoparticles. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these two materials were also determined under the same conditions. The results showed a concentration-dependent effect of antibacterial nanoparticles on the viability of Escherichia coli (E. coli). Moreover, the combination of the stimulations and sterilization considerably enhanced the antimicrobial activity (AMA) of the ZnO suspensions. Poly (lactic acid) (PLA) solutions in 2,2,2-trifluoroethanol (TFE) were mixed with different contents of nanoparticles and spun into nonwoven mats by the electrospinning process. The morphology of the mats was analyzed by scanning electron microscopy (SEM). The amount of nanoparticles contained in the mats was determined by thermogravimetric analysis (TGA). The obtained PLA-based mats showed a fibrous morphology, with an average diameter ranging from 350 to 450 nm, a porosity above 85%, but with the nanoparticles agglomeration on their surface. TGA analysis showed that the loss of ZnO-NPs increased with the increase of ZnO-NPs content in the PLA solutions and reached 79% for 1 wt % of ZnO-NPs, which was mainly due to the aggregation of nanoparticles in solution. The ABA of the obtained PLA mats was evaluated by the dynamic method according to the ASTM standard E2149. The results showed that, above an optimal concentration, the nanoparticle agglomeration reduced the antimicrobial efficiency of PLA mats. These mats have potential features for use as antimicrobial food packaging material

Interactions between PLA, organo-montmorillonite and plasticizer: Synergistic effect on the barrier and mechanical properties of PLA nanocomposites blown films

ABSTRACT: In this study, the impact of incorporating a plasticizer on the compatibility between organo-montmorillonite (OMMt) and polylactic acid (PLA) is investigated, and the resulting barrier and mechanical properties are reported. Four polymers were chosen as plasticizers to prepare the PLA nanocomposite blown films: poly(ethylene glycol), poly(ethylene oxide), polycaprolactone (PCL), and random ethylene-methyl acrylate-glycidyl methacrylate terpolymer. Firstly, 5 wt% of each plasticizer and 3 wt% of OMMt (Dellite® D43B) were mixed simultaneously with PLA in a twin-screw extruder and then introduced into the hopper of a single screw extruder to produce D43B-PLA/plasticizer nanocomposite films. The compatibilization effect was examined based on microstructure observations and thermodynamic predictions. Crystallinity was evaluated using DSC and XRD measurements. The results obtained for permeability and mechanical testing showed that the improvement of barrier and mechanical properties depends directly on the degree of compatibility between plasticizer, OMMt, and PLA. Indeed, the interfacial properties, XRD diffraction, and TEM images showed that a synergistic effect can result from high interfacial interactions between different compounds

A Facile Approach for the Mass Production of Submicro/Micro Poly (Lactic Acid) Fibrous Mats and Their Cytotoxicity Test towards Neural Stem Cells

Despite many of the studies being conducted, the electrospinning of poly (lactic acid) (PLA), dissolved in its common solvents, is difficult to be continuously processed for mass production. This is due to the polymer solution droplet drying. Besides, the poor stretching capability of the polymer solution limits the production of small diameter fibers. To address these issues, we have examined the two following objectives: first, using an appropriate solvent system for the mass production of fibrousmats with fine tunable fiber diameters; second, nontoxicity of the mats towards Neural Stem Cell (NSC). To this aim, TFA(trifluoroacetic acid) was used as a cosolvent, in a mixture with DCM(dichloromethane), and the solution viscosity, surface tension, electrical conductivity, and the continuity of the electrospinning process were compared with the solutions prepared with common single solvents. The binary solvent facilitated PLA electrospinning, resulting in a long lasting, stable electrospinning condition, due to the low surface tension and high conductivity of the binary-solvent system. The fiber diameter was tailored from nano to micro by varying effective parameters and examined by scanning electron microscopy (SEM) and image-processing software. Laminin-coated electrospun mats supported NSC expansion and spreading, as examined using AlamarBlue assay and fluorescent microscopy, respectively

A Facile Approach for the Mass Production of Submicro/Micro Poly (Lactic Acid) Fibrous Mats and Their Cytotoxicity Test towards Neural Stem Cells

Despite many of the studies being conducted, the electrospinning of poly (lactic acid) (PLA), dissolved in its common solvents, is difficult to be continuously processed for mass production. This is due to the polymer solution droplet drying. Besides, the poor stretching capability of the polymer solution limits the production of small diameter fibers. To address these issues, we have examined the two following objectives: first, using an appropriate solvent system for the mass production of fibrous mats with fine-tunable fiber diameters; second, nontoxicity of the mats towards Neural Stem Cell (NSC). To this aim, TFA (trifluoroacetic acid) was used as a cosolvent, in a mixture with DCM (dichloromethane), and the solution viscosity, surface tension, electrical conductivity, and the continuity of the electrospinning process were compared with the solutions prepared with common single solvents. The binary solvent facilitated PLA electrospinning, resulting in a long lasting, stable electrospinning condition, due to the low surface tension and high conductivity of the binary-solvent system. The fiber diameter was tailored from nano to micro by varying effective parameters and examined by scanning electron microscopy (SEM) and image-processing software. Laminin-coated electrospun mats supported NSC expansion and spreading, as examined using AlamarBlue assay and fluorescent microscopy, respectively

Experimental investigation on the consolidation of polypropylene-clay nanocomposite fibers

Peer reviewed: YesNRC publication: Ye

Development of conductive polymeric fibers for flexible electronics applications

Conductive micro and nanofibers have been produced by melt-spinning and electrospinning. Melt-spinning uses mechanical forces to stretch fibers while electrospinning allows the production of fibers using the force of an electric field to stretch them. Alternatively, textile multifilament fibers were coated with intrinsically conducting polymers (ICPs). The fibers were characterized by electron microscopy (SEM, TEM) as well as 4-point probe conductivity measurements.On a produit des nanofibres et des microfibres conductrices par filage par fusion et par \ue9lectrofilature. Le filage par fusion fonctionne gr\ue2ce \ue0 des forces m\ue9caniques pour \ue9tirer les fibres, alors que l\u2019\ue9lectrofilature permet la production de fibres gr\ue2ce \ue0 la force d\u2019un champ \ue9lectrique qui les \ue9tire. Autrement, des fibres textiles multifilaments ont \ue9t\ue9 recouvertes de polym\ue8res intrins\ue8quement conducteurs. Les fibres ont \ue9t\ue9 caract\ue9ris\ue9es par microscopie \ue9lectronique (MEB, MET), ainsi qu\u2019au moyen de mesures de conductivit\ue9 avec une sonde \ue0 quatre points.Peer reviewed: YesNRC publication: Ye

Nano and Micro Fibers for Conductive Applications

Peer reviewed: YesNRC publication: Ye

Strategies for the Fabrication and Characterization of Conductive Fibers Using Electrospinning and Melt-spinning Techniques

Peer reviewed: YesNRC publication: Ye

Experimental investigation on the consolidation of polypropylene-clay nanocomposites fibers

Peer reviewed: YesNRC publication: Ye