Bonding and Spectra of Molecules and Solids

The electronic structure of molecules includes electronic (2-10 eV, UV-Vis absorption), vibrational (10-2 - 2 eV, infrared spectroscopy & Raman scattering), and rotational (10–5 – 10–3 eV, microwave spectroscopy) energy levels that are probed by appropriate spectroscopy methods. Light, incident on a molecule or molecular solid, is either absorbed (IR, single photon, non-zero derivative of dipole moment), or elastically (Rayleigh) or inelastically (Raman, two-photon, non-zero derivative of the polarizability) scattered. Fourier transform infrared (FTIR) spectroscopy finds much use in materials characterization, including in studying the curing of polymer composites now incorporated in aircraft structures. When atoms form solids their electronic structure, particularly the energy levels of the outer electrons involved in the bonding, are significantly altered. Both occupied and unoccupied levels in solids are probed. Photoemission spectroscopy (PES) with X-rays (XPS) or ultraviolet light (UPS) incidence, and inverse PES probe occupied and unoccupied energy levels of surfaces, respectively. X-ray absorption spectroscopy (XAS) complements XPS, and probes unoccupied energy levels of solids. X-ray absorption near-edge structure (XANES) provides information on the final density of unoccupied states, the transition probabilities, and many body effects. Extended X-ray absorption fine structure (EXAFS) provides element-specific nearest neighbor distances and their coordination number.

Fabrication of Soft Sensor Using Laser Processing Techniques: For the Alternative 3D Printing Process

Recently, the rapid prototyping process was actively studied in industry and academia. The rapid prototyping process has various advantages such as a rapid processing speed, high processing freedom, high efficiency, and eco-friendly process compared to the conventional etching process. However, in general, it is difficult to directly apply to the fabrication of electric devices, as the molding made by the rapid prototyping process is usually a nonconductive polymer. Even when a conductive material is used for the rapid prototyping process, the molding is made by a single material; thus, its application is limited. In this study, we introduce a simple alternative process for the fabrication of a soft sensor using laser processing techniques. The UV laser curing of polymer resin and laser welding of nanowires are conducted and analyzed. Through the laser processing techniques, we can easily fabricate soft sensors, which is considered an alternative 3D printing process for the fabrication of soft sensors.

Investigation of the mechanical properties of polymer matrices based on adhesive binders

The paper considers methods for manufacturing polymer-matrix samples for the determination of mechanical properties outlining the basic approach to the development of modes for pouring and curing of polymer blocks. Samples were made of cured adhesive binders VSK-50, VSK-14-2m, VSK-14-2mR, VSK-14-2mRm, and tests were carried out to determine the following characteristics: tensile and flexural strength, elongation, tensile modulus when stretching and bending.

Evaluation on Curing Properties and Kinetics of Isophthalonitrile Oxide

N,N-dihydroxybenzene-1,3-dicarboximidoyl dichloride was synthesized from benzene-1,3-dicarboxaldehyde and characterized by fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H and 13C NMR). The elastomer was prepared through the 1,3-dipolar cycloaddition of reaction between liquid polybutadiene (LPB) and isophthalonitrile oxide in this work. The tensile strength of different elastomer was enhanced from 0.14 MPa to 0.33 MPa as the elongation at break decreased from 145% to 73%, and the modulus increased from 0.09 kPa to 0.47 kPa. The parameters of kinetic indicated that the curing reaction was fi rst order reaction and the apparent activation energy of each curing system was less than 10.10 kJ/mol when the content of N,N-dihydroxybenzene-1,3- dicarboximidoyl dichloride was increased from 7% to 12%. These results suggested that nitrile oxides achieved curing of polymer binders at room temperature and this work had defi nite guiding signifi cance for the application of nitrile oxides in polymer binders.

Sintering Method in Pharmaceutical Sciences: An Overview

In the pharmaceutical science, sintering has been described as the mechanism for the strengthening of the mechanical properties of consolidated pharmaceutical powders at elevated temperatures, for solid-bond formation during tablet compression, and for thermal curing of polymer-latex film coatings. The concept of sintering was applied in the investigation of the effect of heating on the mechanical properties of pharmaceutical powders. The sintering process has been used for the fabrication of controlled-release matrix tablets and for the stabilization of the drug permeability of film coatings derived from various pharmaceutical lattices. The changes in the hardness and disintegration time of tablets stored at elevated temperatures were described as a result of sintering. The formation of solid bonds within powder bed during tablet compression was also studied in terms of sintering. The concept of sintering was applied in the investigation of the effect of heating on the mechanical properties of pharmaceutical powders.

A Review on Sintering Technique in Pharmaceutical Sciences

In the pharmaceutical science, sintering has been described as the mechanism for the strengthening of the mechanical properties of consolidated pharmaceutical powders at elevated temperatures, for solid-bond formation during tablet compression, and for thermal curing of polymer-latex film -Coatings. The concept of sintering was applied in the investigation of the effect of heating on the mechanical properties of pharmaceutical powders. The formation of solid bonds within a powder bed during tablet compression was also studied in terms of sintering. The changes in the hardness and Disintegration time of tablets stored at elevated temperatures were described as a result of sintering. Furthermore, the sintering process has been used for the fabrication of sustained – release matrix tablets and for the stabilization of the drug permeability of film coatings derived from various pharmaceutical lattices.