Effect of Different Molecular Weight and Concentration of Polyethylene Glycol (PEG) on Tensile and Morphology of Sago Starch Film

Sago starch is a seasonal based plantation and widely found in Asia country. Its application mainly in cooking such as biscuits and as a thickener in jellies. To further utilize its application, bioplastic from sago starch was developed. In this study, sago starch films were prepared through a blending and casting method using polyethylene glycol (PEG) as a plasticizer by varying its molecular weights and concentrations. The interaction between starch and PEG in the blend was studied using FTIR technique. The effect on transparency, tensile stress, Young’s modulus as well as elongation percentages of the films was also examined. The results suggested that the addition of low molecular weight PEG (400 g.mol-1) increased the tensile stress of sago films from 33.51 MPa up to 39.11 MPa. Nevertheless, incorporation of high molecular weight of PEG (4000 g.mol-1) decreased the tensile strength of the film. Tensile strength and elongation at break of sago films increased with increasing of PEG concentration up to 2% and decreased with further increased of PEG content. Results indicated that there was a miscibility between these two components.

Effect of the Environment on the Characteristics of a Polymer

The polycarbonate (PC) is a highly valued polymeric material for its various characteristics and low cost. Its transparency and impact resistance justify its use in a severe radiation and temperature environment. The aim of this article is to subject this material to aging under ultraviolet (UV) radiation with a wavelength of 253 nm and a temperature of 80°C for various times. The physicochemical and mechanical characterizations of the virgin and aged material have allowed the revelation of the aging effects on the properties. The Fourier Transform Infrared Spectroscopy (FTIR) technique highlight breaks in chemical bonds in the molecular chains of the PC subjected to the combined effects of UV and heat. X-ray analysis have showed a reduction in crystallites and a tendency towards an amorphous state at short times, but the degree of crystallinity increases again at long exposure times of the material. As a result, the microhardness of the aged material is strongly affected on the exposed surface with less effect depending on the depth.

Mineral Heterogeneity Characterization of the Lacustrine Yanchang Shales, Ordos Basin Using Micro-Fourier Transform Infrared Spectroscopy (Micro-FTIR) Technique

Shale is a typical fine-grained sedimentary rock with small grain sizes of matrix components, significant lithofacies variation of rock texture and structure, and strong heterogeneity of organic matter and mineral compositions. Characterization of mineral compositions and their heterogeneity in micro- to nanoscale are the key parameters to gas shale pore structure and rock physical properties. In order to study the microscale mineralogy heterogeneity of the lacustrine shales in the Triassic Yanchang Formation in the Ordos Basin, the micro-Fourier transform infrared spectroscopy (micro-FTIR) technique was conducted. Based on the specific micro-FTIR spectra peaks, the abundance of mineral compositions can be quantitatively determined in the selected microscale areas. The results show that within the range of 80 μm micro-FTIR test interval, both massive argillaceous shale and silty interlayered shale show obvious heterogeneity; in particular, the relatively homogeneous shale observed by the naked eyes also has strong mineral heterogeneity. The results of micro-FTIR spectra are basically consistent with the bulk X-ray diffraction (XRD) data. The advantage of this micro-FTIR technique includes higher resolution (less than 100 μm) and in situ mineral characterization of shale samples at micro- and nanoscale.

Thermal Decomposition of Olive-Mill Byproducts: A TG-FTIR Approach

In this study, the combustion of olive byproducts was investigated using the TG-FTIR technique. Different types of olive biomass were considered: twigs, leaves, olive-mill waste from the two-phase decanting method, and wastewater from the three-phase system. The reaction regions, ignition, and burnout temperatures at different heating rates were determined using TG/DTG analysis and the thermogravimetry results. Comprehensive combustion, ignition, burnout, and flammability indexes were also calculated. The highest combustion index values were obtained for waste from the three-phase system, followed by the two-phase decanting method, then with leaves and small twigs. The order of the index values indicated that the sample from the three-phase process ignited more quickly and yielded faster. The changes in activation energy calculated using different model-free isoconversional methods—Friedman, Ozawa–Flynn–Wall, and Kissinger–Akahira–Sunose—fell within the range of 130–140 kJ/kmol. FTIR analyses presented differences in the exhaust gas composition for specific combustion temperature ranges.

Marginal Adaptation Assessment for Two Composite Layering Techniques Using Dye Penetration, AFM, SEM and FTIR: An In-Vitro Comparative Study

Do the new, modern dental resin composites improve the sealing in cavities restorations? The present study was designed to compare the effect of two different, but most used layering techniques of the dental composite in reducing the marginal microleakage when a brand-new material is used; Class I black cavities were prepared on 120 human extracted teeth and then restored using oblique and horizontal layering technique. The dye penetration analysis, the atomic force microscopy (AFM), scanning electron microscopy (SEM) together with energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infra-red spectroscopy (FTIR) technique were used to assess the adaptation of the restorative material to the dental structures. Some better results were obtained for oblique layering technique, but the differences to the other method have not been statistically validated. The composite layering technique still remains an open quest and, moreover, in vivo studies should be designed in order to assess microleakage in real conditions of the oral environment.

Chemical Functionalization of Bacterial Cellulose Film for Enhancing Output Performance of Bio-Triboelectric Nanogenerator

Triboelectric nanogenerator (TENG) is a promising technology for converting mechanical energy into electrical energy. In the present research, a bio-TENG based on bacterial cellulose (BC) was fabricated, and the performance was improved by surface modification. The BC films were chemically functionalized by phosphorylation and sulfonation processes. The FTIR technique confirmed the functional groups on the phosphorylated and sulfonated BCs. The hydrophobic/hydrophilic properties were studied and found that the unmodified BC, as well as the functionalized BC, were both hydrophilic. The structure and morphology of the BC nanofibers were investigated by SEM imaging. It was shown that after phosphorylation and sulfonation, the BC nanofiber surface became rougher, and the fibers were densely packed. The pores between the nanofibers almost disappeared. These have resulted from the coating of the phosphate and sulfonic functional groups on the BC nanofibers. For TENG measurement, the BC film was paired with PTFE under a single-electrode measuring mode. The functionalized BC showed improved output performance compared to the unmodified BC, possibly due to the rougher and denser BC surface and the change in the BC triboelectric potential. This research demonstrated a novel but straightforward way to enhance the output performance of the bio-TENG.

Experimental Investigation on Green Synthesis of FeNPs using Azadirachta indica leaves

In the field of nanotechnology, developing an environmentally friendly method for the synthesis of iron nanoparticles (FeNPs) an important aspect. The use of secondary metabolites from plant leaf extract has recently emerged as a novel technology for the synthesis of various nanoparticles, according to recent studies. The leaf extract of Azadirachta indica was used to synthesize iron nanoparticles in this research. The effects of reactant concentrations, reaction temperature and pH of the solution on the synthesis process of iron nanoparticles were studied. The formation of iron nanoparticles in dispersion was monitored using a UV-Visible Spectrophotometer that analyzed absorbance spectra. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) characterized the morphology of iron nanoparticles and results reveal the particles are spherical in shape with an average size of 48 nm. The following are the ideal conditions for synthesis: leaf extract 15%, [FeCl 3 ] = 1.0 mM, pH 6.0 and temperature 60◦C. The plant biomolecules induce the reduction of Fe 3+ ions to FeNPs and act as a capping and stabilizing agent, which is confirmed by the FTIR technique. Therefore, they have good stability for various applications.

Analysis of luminescence, morphological and thermal behaviour of conjugated polymer/CdS electrospun nanofiber

Electro spun composite nanofibers of three series were prepared using different polymers (P1, P2, P3) and cadmium sulphide (CdS). Organic polymers of carbazole based quinoline (P1), quinoxaline (P2), and pyrazine (P3) hybrid with inorganic CdS nanofibers were characterized by XRD and FTIR technique. Collective arrangement of spiderweb-like morphology was observed for all nanofibers. Deviations of absorption and photoluminescence were monitored and a significant blue shift was found after doping CdS and PVA. It was found that the changes in the PL spectra of polymers originated from the chemical interactions between polymer and CdS. The diameter of nanofibers was observed as 127-347 nm from SEM analysis and 66-213 nm from TEM analysis. Optimum thermal stability of the composite nanofibers was achieved up to 200 °C. Compared with pure polymers and CdS, present nanofibers were good thermal stability, apparent blue shift with bluish emission which is suitable for optoelectronics application.

IR SPECTRA OF γ-IRRADIATED NANOCOMPOSITES ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE / α-SiO2

The effect on concentration of the nanofiller α-SiO2 filler and irradiation on the FTIR spectra of pure films polymer (ultra-high molecular weight polyethylene (UHMWPE)) and doped them this α-SiO2 with different concentration (0, 1, 3, 5 vol.%) were investigated using FTIR technique. The samples were irradiated for different doses like 0, 50, and 100 kGy by 60Co source with a dose rate of approximately 3.3∙10-3 kGy/h at room temperature. The correlation of absorption bands with occurrence of corresponding groups was carried out. The occurrence of a series of a characteristic absorptions bands of composites was shown.