The Effect of Plasticizers on the Polypyrrole-Poly(vinyl alcohol)-Based Conducting Polymer Electrolyte and Its Application in Semi-Transparent Dye-Sensitized Solar Cells.

In this work, the quasi-solid-state polymer electrolyte containing poly(vinyl alcohol)-polypyrrole as a polymer host, potassium iodide (KI), iodine (I2), and different plasticizers (EC, PC, GBL, and DBP) was successfully prepared via the solution casting technique. Fourier transform infrared spectroscopy (FTIR) was used to analyze the interaction between the polymer and the plasticizer. X-ray diffraction confirmed the reduction of crystallinity in the polymer electrolyte by plasticizer doping. The ethylene carbonate-based polymer electrolyte showed maximum electrical conductivity of 0.496 S cm-1. The lowest activation energy of 0.863 kJ mol-1 was obtained for the EC-doped polymer electrolyte. The lowest charge transfer resistance Rct1 was due to a faster charge transfer at the counter electrode/electrolyte interface. The polymer electrolyte containing the EC plasticizer exhibited an average roughness of 23.918 nm. A photo-conversion efficiency of 4.19% was recorded in the DSSC with the EC-doped polymer electrolyte under the illumination of 100 mWcm-2.

Characterization of a new cellulosic natural fiber extracted from the root of Ficus religiosa tree.

Physical, chemical, thermal and crystalline properties of new natural fiber extracted from the root of Ficus Religiosa tree(FRRF) are reported in this study. The chemical analysis and X-ray diffraction (XRD) analysis results ensured the presence of higher quantity of cellulose content (55.58 wt%) in the FRRF. Nuclear Magnetic Resonance (NMR) spectroscopy analysis is transported away to support the chemical groups present in the considered fibre. Thermal stability (325 °C), maximum degradation temperature (400 °C) and kinetic activation energy (68.02 kJ/mol.) of the FRRF areestablished by the thermo gravimetric analysis. The diameter (25.62 µm) and density (1246 kg/m3) of the FRRF have been found by the physical analysis. Scanning electron microscope analysis (SEM) and Atomic force microscope analysis (AFM) outcomes revealed that FRRF has the relatively smoothest surface. Altogether the above outcomes proved that novel FRRF is the desirable reinforcement to fabricate the fiber reinforced composite materials.

Characterization of raw and alkali treated new natural cellulosic fibres extracted from the aerial roots of banyan tree.

The objective of this investigation is to check the suitability novel cellulosic fibre extracted from the aerial roots of Banyan tree (ARBFs) as reinforcement in fibre reinforced plastics. The Fundamental properties of ARBFs such as density, tensile strength, chemical composition, crystallinity index, crystalline size, thermal stability, maximum degradation temperature and surface roughness were studied. The chemical analysis results revealed that after the alkalization cellulose content was improved while hemi-cellulose, lignin and wax content were demised. The enhancement in the crystallinity index (76.35% from 72.47%) and crystalline size (7.74 nm from 6.28 nm) of alkali treated ARBFs were evidenced by the X-ray diffraction analysis. Thermal analysis results confirmed that maximum degradation temperature (368 °C) and kinetic activation energy (75.45 kJ/mol) of alkali treated ARBFs had increased from 358 °C and 72.65 kJ/mol respectively. The results of scanning electron microscopic and atomic force microscopic analysis exhibited that impurities and wax on the outer surface of the ARBFs were removed after the alkali treatment. All the above finding concluded that ARBFs is the appropriate material to use as a reinforcement in fibre reinforced plastics.

Characterization of cellulose fibers in Thespesia populnea barks: Influence of alkali treatment.

Natural fibers are emerging as best alternatives for synthetic materials in selective applications. These fibers may not have the required properties in its raw form and hence needs some alterations in its characteristics. Likely, this article reports enhancement in surface and structural properties of Thespesia populnea bark fiber treated with NaOH under various concentration and soaking period. Fibers treated with 5% NaOH for 60 min yields noteworthy mechanical strength (678.41 ± 48.91 MPa) owing to its relatively high cellulose fraction (76.42%). Fourier transform infrared spectra endorses the removal of non-cellulosic compounds and X-ray diffraction studies reveals 13.6% growth in the size of cellulose crystals on optimally treated fibers. Weibull distribution model statistically interprets the reliability of acquired tensile test results. Finally, microscopic examinations with scanning electron microscopy and atomic force microscopy explore that fiber surface turns rough after alkali treatment and makes it appropriate for reinforcement in polymer matrices.

Assessment of cellulose in bark fibers of Thespesia populnea: Influence of stem maturity on fiber characterization.

Cellulose is the key constituent of natural fibers and its proportion significantly varies with the growth of the plant. Hence, a study on the influence of plant maturity on fiber properties is essential to recognize optimal fiber source. In this investigation, cellulose fibers were successfully extracted from Thespesia populnea tree barks of approximately 10 mm-80 mm diameter stem and the influence of stem growth on physiochemical, thermal, mechanical and morphological characteristics of the fiber were investigated. The diameter of fiber increased from 150 µm to 200 µm with stem growth meanwhile its water uptake capability decreases by 13.8%. FTIR spectra and thermal analysis confirm the presence of cellulose compound in fiber structure, also the fiber can be stable up to 318 °C. The XRD outcome estimates 44-49% crystallinity index with an average crystallite size of 29.625 Å. Under the tensile load, fiber fails primarily by brittle fracture and its tensile strength ranges from 559 MPa to 329 MPa with an average elongation between 2.9% and 1.7%. Morphology analysis illustrates that fiber surface is becoming rough on maturity and can offer good interfacial strength when reinforced with composites.

Isolation and characterization of cellulose fibers from Thespesia populnea barks: A study on physicochemical and structural properties.

Cellulose, a major proportion of all plant resources are not utilized at its best. Hence, this investigation explores the potential of cellulose fraction in bark fibers of Thespesia populnea for real time use by evaluating its anatomical, physicochemical, mechanical, thermal and morphological properties. Anatomical studies confirm two types of phloem fiber cells based on dimensions of secondary cell wall and lumen. Significant concentration of cellulose (70.12%) helps to attain favorable outcomes in tensile strength (557.82 ±â€¯56.29 MPa). FTIR spectra confirm the presence of cellulosic compound in fiber structure and the size of crystalline cellulose is estimated as 35.76 Šusing XRD results. Thermal profile of TGA and DSC validates that fiber is steady up to 245.4 °C and cellulose degradation befalling between 250 °C and 370 °C accounts for major weight loss in fiber. Images acquired through SEM and AFM depict that the fiber surface is smooth with average roughness of 3.002 nm.

Effect of bio-additives on physico-chemical properties of fly ash-ground granulated blast furnace slag based self cured geopolymer mortars.

Heat curing catalyzed the geopolymerization reaction in geopolymers whereas the practical challenges in applying heat curing process limited the applications of geopolymers to precast elements alone. Bio-additives inclusion could facilitate ambient temperature curing that lead to environment friendly self cured geopolymers. Natural sugars (molasses/palm jaggery/honey) and terminalia chebula were used as bio-additives in fly ash (FA) and ground granulated blast furnace slag (GGBS) based geopolymer mortars. X-ray diffraction (XRD), Fourier transform infrared spectral (FTIR), thermogravimetric (TG/DTG) and scanning electron microscopic (SEM) studies were used for the characterization for all geopolymer mortar samples. Physico-chemical test results of bio-additives added FA-GGBS based self cured geopolymer mortar samples showed XRD peaks at 2θ = 20°, 26°, 39°, 48°, 66° and 75°, FTIR bands at 3430, 2922, 1390, 1270, 1120 and 881cm-1, DTG peaks at 120 °C, 126 °C and 134 °C that led to the conclusion that development of differences in geopolymer reaction products, intense structural reorganization leading to stable geopolymer matrix and more ordered geopolymer gels. Further SEM observations revealed compact and dense microstructure development in bio-additives added FA-GGBS based self cured geopolymer mortar samples.

Characterization of a novel natural cellulosic fiber from Prosopis juliflora bark.

Natural fibers from plants are ideal choice for producing polymer composites. Bark fibers of Prosopis juliflora (PJ), an evergreen plant have not been utilized for making polymer composites yet. Hence, a study was undertaken to evaluate their suitability as a novel reinforcement for composite structures. PJ fiber (PJF) was analyzed extensively to understand its chemical and physical properties. The PJF belonged to gelatinous or mucilaginous type. Its lignin content (17.11%) and density (580 kg/m(3)) were relatively higher and lower, respectively in comparison to bark fibers of other plants. The free chemical groups on it were studied by FTIR and XRD. It had a tensile strength of 558±13.4 MPa with an average strain rate of 1.77±0.04% and microfibril angle of 10.64°±0.45°. Thermal analyses (TG and DTG) showed that it started degrading at a temperature of 217 °C with kinetic activation energy of 76.72 kJ/mol.