scholarly journals The Impact of Composition and Morphology on Ionic Conductivity of Silk/Cellulose Bio-Composites Fabricated from Ionic Liquid and Varying Percentages of Coagulation Agents

2020 ◽  
Vol 21 (13) ◽  
pp. 4695 ◽  
Author(s):  
Bailey Blessing ◽  
Cory Trout ◽  
Abneris Morales ◽  
Karleena Rybacki ◽  
Stacy A. Love ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Ionic Conduction ◽  
Hydrophobic Interactions ◽  
Gravimetric Analysis ◽  
Dielectric Relaxation Spectroscopy ◽  
Scanning Calorimetry ◽  
Electrolyte Membranes ◽  
Bombyx Mori Silk ◽  
The Impact

Blended biocomposites created from the electrostatic and hydrophobic interactions between polysaccharides and structural proteins exhibit useful and unique properties. However, engineering these biopolymers into applicable forms is challenging due to the coupling of the material’s physicochemical properties to its morphology, and the undertaking that comes with controlling this. In this particular study, numerous properties of the Bombyx mori silk and microcrystalline cellulose biocomposites blended using ionic liquid and regenerated with various coagulation agents were investigated. Specifically, the relationship between the composition of polysaccharide-protein bio-electrolyte membranes and the resulting morphology and ionic conductivity is explored using numerous characterization techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray scattering, atomic force microscopy (AFM) based nanoindentation, and dielectric relaxation spectroscopy (DRS). The results revealed that when silk is the dominating component in the biocomposite, the ionic conductivity is higher, which also correlates with higher β-sheet content. However, when cellulose becomes the dominating component in the biocomposite, this relationship is not observed; instead, cellulose semicrystallinity and mechanical properties dominate the ionic conduction.

Development of ion conducting polymer gel electrolyte membranes based on polymer PVdF-HFP, BMIMTFSI ionic liquid and the Li-salt with improved electrical, thermal and structural properties

2015 ◽  
Vol 3 (28) ◽  
pp. 7305-7318 ◽  
Author(s):  
Shalu Shalu ◽  
Varun Kumar Singh ◽  
Rajendra Kumar Singh
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Ionic Conduction ◽  
Polymer Electrolyte Membranes ◽  
Polymer Gel ◽  
Polymer Gel Electrolyte ◽  
Electrolyte Membranes ◽  
Crystalline Nature ◽  
Ion Conducting ◽  
Ion Conducting Polymer

Figure (a) shows that the semi-crystalline nature of the polymer PVdF-HFP and Figure (b) shows that the polymer chain became flexible on the addition of LiTFSI salt. Furthermore, on the addition of IL in polymer electrolyte membranes, the membranes became more flexible and provide high ionic conduction (because of more availability of ions) in the system resulting in enhancement of the ionic conductivity (see Figure (c)).

Experimental Investigating the Impact of Ionic Liquid on PET’s Properties

2018 ◽  
Author(s):  
Waleed K. Ahmed
Keyword(s):  
Ionic Liquid ◽  
Thermo Gravimetric Analysis ◽  
Melt Flow Index ◽  
Nanoindentation Test ◽  
Flow Index ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Weight Percentage ◽  
Mixing Ratios ◽  
The Impact

This study presents an experimental laboratory investigation done on the Polyethylene terephthalate – PET that is used for food grade (water bottle) by mixing with ionic liquid. Both thermal and mechanical properties with a varying weight percentage of ionic liquid are investigated. Mainly, at different mixing ratios of PET-Ionic liquid of (2, 3, 5, 7 and 10%), impact of the ionic liquid on the characteristics of the PET are examined through MFI (melt flow index), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), nanoindentation methods as well as Fourier Transform Infrared (FTIR) spectroscopy. In general, the estimated results indicated that the stiffness as well as the hardness acquired from nanoindentation test for the PET blends, decrease as long as the concentration increases.

Preparation by solution mixing and characterization of condensation type poly(dimethyl siloxane)/graphene nanoplatelets composites

2021 ◽  
pp. 002199832110558
Author(s):  
Panayiotis Ketikis ◽  
Efthimios Damopoulos ◽  
Georgios Pilatos ◽  
Panagiotis Klonos ◽  
Apostolos Kyritsis ◽  
...  
Keyword(s):  
Graphene Nanoplatelets ◽  
Matrix Composites ◽  
Dielectric Relaxation Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Dimethyl Siloxane ◽  
Diffraction Patterns ◽  
The Impact

The impact of the incorporation of graphene nanoplatelets (GN) on the properties of hydroxyl-terminated poly(dimethylsiloxane) (PDMS) matrices was investigated. The composites were prepared by solution mixing, using tetrahydrofuran (THF) as a solvent. Brookfield viscosimetry, implemented during the vulcanization process, revealed that GN increases the viscosity of the system, compared to pristine PDMS, proportionally to its concentration. X-ray diffraction patterns suggested an efficient dispersion of GN in the polysiloxane matrix. The D and G bands ratio (ID/IG) calculation, based on RAMAN spectra of GN/PDMS specimens, revealed more defects in graphene nanoplatelets when incorporated in the PDMS matrix. By differential scanning calorimetry (DSC), a marginal increase in crystallization, glass transition and melting temperatures of PDMS in GN/PDMS composites was observed. Improvement of the thermal stability of LMW PDMS composites, especially for higher GN concentrations (3 and 5 phr), was noticed by thermogravimetric analysis (TGA). Additionally, GN enhanced the tensile strength of composites, up to 73% for the 3 phr GN/LMW PDMS composite. A significant increase in the elongation at break was recorded, whereas no effect on the modulus of elasticity was recorded. The decrease in toluene-swelling, for the LMW PDMS matrix composites, was attributed to the increase in the tortuosity path because of the efficient dispersion of GN. A decrease in oxygen permeability of 55–65% and 44–58% was measured in membranes made of PDMS composites containing 0.5 phr and 1 phr GN, respectively. Dielectric relaxation spectroscopy (DRS) measurements recorded a significant increase in the conductivity of the higher graphene content composites.

Preparation of Two Novel Ionic Electroconductive Polyurethanes Functionalized with the Backbone of Ionic Liquid

2013 ◽  
Vol 668 ◽  
pp. 259-262
Author(s):  
Ding Jun Zhang ◽  
Chao Yun Qu ◽  
Yu Xian Chen
Keyword(s):  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Ionic Liquid ◽  
Surface Resistance ◽  
High Yield ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Facile Synthesis ◽  
Scanning Calorimetry ◽  
Structures And Properties

The facile synthesis of two new Ionic electroconductive polyurethanes with the framework of ionic liquids, i.e., PUR-T: synthesized with isocyanate TDI; PUR-H: synthesized with isocyanate HDL, are described. Their structures and properties were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC) and the surface resistance meter. The effects of the different kinds of isocyanate on electrical conductivity of PUR were also investigated. It was found that their electrical conductivity can be optimized by changing the reaction temperature. The PUR-H, which exhibits an electrical conductivity of 1.0×104 Ω surface resistance, could be obtained in high yield, up to 65% at 90 oC for 12h.

scholarly journals Fluoropolymer/Glycidyl Azide Polymer (GAP) Block Copolyurethane as New Energetic Binders: Synthesis, Mechanical Properties, and Thermal Performance

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2706
Author(s):  
Minghui Xu ◽  
Xianming Lu ◽  
Ning Liu ◽  
Qian Zhang ◽  
Hongchang Mo ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Mechanical Performance ◽  
Gel Permeation Chromatography ◽  
Raw Material ◽  
Toluene Diisocyanate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Glycidyl Azide Polymer ◽  
The Impact ◽  
Glycidyl Azide

In order to enhance the application performance of glycidyl azide polymer (GAP) in solid propellant, an energetic copolyurethane binder, (poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane] glycol-block-glycidylazide polymer (PBFMO-b-GAP) was synthesized using poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane] glycol (PBFMO), which was prepared from cationic polymerization with GAP as the raw material and toluene diisocyanate (TDI) as the coupling agent via a prepolymer process. The molecular structure of copolyurethanes was confirmed by attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR–FTIR), nuclear magnetic resonance spectrometry (NMR), and gel permeation chromatography (GPC). The impact sensitivity, mechanical performance, and thermal behavior of PBFMO-b-GAP were studied by drop weight test, X-ray photoelectron spectroscopic (XPS), tensile test, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA), respectively. The results demonstrated that the introduction of fluoropolymers could evidently reduce the sensitivity of GAP-based polyurethane and enhance its mechanical behavior (the tensile strength up to 5.75 MPa with a breaking elongation of 1660%). Besides, PBFMO-b-GAP exhibited excellent resistance to thermal decomposition up to 200 °C and good compatibility with Al and cyclotetramethylene tetranitramine (HMX). The thermal performance of the PBFMO-b-GAP/Al complex was investigated by a cook-off test, and the results indicated that the complex has specific reaction energy. Therefore, PBFMO-b-GAP may serve as a promising energetic binder for future propellant formulations.

scholarly journals Optimization of the Electrochemical Performance of a Composite Polymer Electrolyte Based on PVA-K2CO3-SiO2 Composite

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 92
Author(s):  
Bashir Abubakar Abdulkadir ◽  
John Ojur Dennis ◽  
Yas Al-Hadeethi ◽  
Muhammad Fadhlullah Bin Abd. Shukur ◽  
E. M. Mkawi ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Ionic Conduction ◽  
Electrochemical Impedance ◽  
Physicochemical Characterization ◽  
Composite Polymer Electrolyte ◽  
Composite Polymer ◽  
Energy Storage Devices ◽  
Scanning Calorimetry ◽  
Thermal Stabilities

Composite polymer electrolyte (CPE) based on polyvinyl alcohol (PVA) polymer, potassium carbonate (K2CO3) salt, and silica (SiO2) filler was investigated and optimized in this study for improved ionic conductivity and potential window for use in electrochemical devices. Various quantities of SiO2 in wt.% were incorporated into PVA-K2CO3 complex to prepare the CPEs. To study the effect of SiO2 on PVA-K2CO3 composites, the developed electrolytes were characterized for their chemical structure (FTIR), morphology (FESEM), thermal stabilities (TGA), glass transition temperature (differential scanning calorimetry (DSC)), ionic conductivity using electrochemical impedance spectroscopy (EIS), and potential window using linear sweep voltammetry (LSV). Physicochemical characterization results based on thermal and structural analysis indicated that the addition of SiO2 enhanced the amorphous region of the PVA-K2CO3 composites which enhanced the dissociation of the K2CO3 salt into K+ and CO32− and thus resulting in an increase of the ionic conduction of the electrolyte. An optimum ionic conductivity of 3.25 × 10−4 and 7.86 × 10−3 mScm−1 at ambient temperature and at 373.15 K, respectively, at a potential window of 3.35 V was observed at a composition of 15 wt.% SiO2. From FESEM micrographs, the white granules and aggregate seen on the surface of the samples confirm that SiO2 particles have been successfully dispersed into the PVA-K2CO3 matrix. The observed ionic conductivity increased linearly with increase in temperature confirming the electrolyte as temperature-dependent. Based on the observed performance, it can be concluded that the CPEs based on PVA-K2CO3-SiO2 composites could serve as promising candidate for portable and flexible next generation energy storage devices.

Effects of Natural Clay on Ionic Conductivity, Crystallinity and Thermal Properties of PEO-LiCF3SO3-Natural Clay as Solid Polymer Electrolyte Nanocomposites

2019 ◽  
Vol 803 ◽  
pp. 98-103 ◽  
Author(s):  
Pattranuch Pongsuk ◽  
Jantrawan Pumchusak
Keyword(s):  
Thermal Properties ◽  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Solid Polymer Electrolyte ◽  
Solid Polymer ◽  
Natural Clay ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Halloysite Nanotube ◽  
Electrolyte Membranes

The polymer nanocomposites of PEO-LiCF3SO3 based solid polymer electrolyte were prepared using two kinds of natural clays, which are halloysite nanotube (HNT) and montmorillonite (MMT) nanoparticle. Different contents (0, 1, 5 and 10wt %) of halloysite nanotube (HNT) and montmorillonite (MMT) nanoparticle were explored. Solid polymer electrolyte nanocomposite film was prepared by solution casting method. The ionic conductivity, crystallinity and thermal properties of solid polymer electrolyte membranes were studied by impedance spectroscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. It was found that HNT provided higher ionic conductivity for solid polymer electrolyte nanocomposite than what MMT did. The highest ionic conductivity at room temperature was found at 5% HNT as 2.068 x 10-5 S.cm-1. The ion-polymer interactions between PEO-LiCF3SO3 and natural clay nanoparticle were investigated by using Fourier transform infrared (FTIR) spectra. The PEO-LiCF3SO3-5%HNT showed good oxidative stability than PEO-LiCF3SO3 composite.

scholarly journals Improvement of Proton-ExchangeMembranes Based on(1x)(H3PO2/PVA)-xTiO2

2017 ◽  
Vol 13 (25) ◽  
pp. 153-166 ◽  
Author(s):  
M E Fernandez ◽  
G Murillo ◽  
R A Vargas ◽  
D Peña Lara ◽  
J E Diosa
Keyword(s):  
Ionic Conductivity ◽  
Molar Fraction ◽  
Weight Percent ◽  
Polymer Electrolyte Membranes ◽  
Conductivity Measurements ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Hypophosphorous Acid ◽  
Polymer Systems ◽  
Electrolyte Membranes

Using impedance spectroscopy (IS), differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), and infrared spectroscopy (IR) tech-niques to study the polymer electrolyte membranes based on poly(vinylalcohol) (PVA) and hypophosphorous acid (H3PO2) with different tita-nium oxide nanoparticles (TiO2) concentrations. The polymer systems(1−x)(H3PO2/ PVA) +xTiO2were prepared using the sol-casting methodand different weight percent of TiO2,x≤10.0œ. The DSC results showthat the glass transition for molar fraction P/OH = 0.3 appears around 75°Cand for the samples doped with TiO2around 35°C; the melting pointfor all membranes appear around 175°C. The FTIR spectra show changesin the profiles of the absorption bands with the addition of H3PO2andthe different concentrations of TiO2. The IS results show dielectric andconductivity relaxations as well as a change in DC ionic conductivity withthe TiO2content. The order of the ionic conductivity is about10−2S/cmfor 5.0œof TiO2. The TGA in the heating run shows water loss that is inagreement with DC conductivity measurements.

scholarly journals Silk-Cellulose Acetate Biocomposite Materials Regenerated from Ionic Liquid

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2911
Author(s):  
Ashley Rivera-Galletti ◽  
Christopher R. Gough ◽  
Farhan Kaleem ◽  
Michael Burch ◽  
Chris Ratcliffe ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Cellulose Acetate ◽  
Biomedical Applications ◽  
Strong Interactions ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Pure Cellulose ◽  
Secondary Structure Analysis ◽  
Bombyx Mori Silk ◽  
Protein Molecular Weight

The novel use of ionic liquid as a solvent for biodegradable and natural organic biomaterials has increasingly sparked interest in the biomedical field. As compared to more volatile traditional solvents that rapidly degrade the protein molecular weight, the capability of polysaccharides and proteins to dissolve seamlessly in ionic liquid and form fine and tunable biomaterials after regeneration is the key interest of this study. Here, a blended system consisting of Bombyx Mori silk fibroin protein and a cellulose derivative, cellulose acetate (CA), in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIMAc) was regenerated and underwent characterization to understand the structure and physical properties of the films. The change in the morphology of the biocomposites (by scanning electron microscope, SEM) and their secondary structure analysis (by Fourier-transform infrared spectroscopy, FTIR) showed that the samples underwent a wavering conformational change on a microscopic level, resulting in strong interactions and changes in their crystalline structures such as the CA crystalline and silk beta-pleated sheets once the different ratios were applied. Differential scanning calorimetry (DSC) results demonstrated that strong molecular interactions were generated between CA and silk chains, providing the blended films lower glass transitions than those of the pure silk or cellulose acetate. All films that were blended had higher thermal stability than the pure cellulose acetate sample but presented gradual changes amongst the changing of ratios, as demonstrated by thermogravimetric analysis (TGA). This study provides the basis for the comprehension of the protein-polysaccharide composites for various biomedical applications.

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