Selective detection of microcracks under the surface of glass substrates by non-contact stress-induced light-scattering method with temperature variations

Demand for flexible electronics is increasing due to recent global movements related to IoT. In particular, the ultra-thin glass substrate can be bent, its use is expanding for various applications such as thin liquid crystal panels. On the other hand, fine-polishing techniques such as chemical mechanical polishing treatments, are important techniques in glass substrate manufacturing. However, these techniques may cause microcracks under the surface of glass substrates because they use mechanical friction. We propose a novel non-contact thermal stress-induced light-scattering method (N-SILSM) using a heating device for inspecting surfaces to detect polishing-induced microcracks. In this report, we carry out the selective detection of microcracks and tiny particles using a N-SILSM with temperature variation. Our results show that microcracks and tiny particles can be distinguished and measured by a N-SILSM utilizing temperature change, and that microcrack size can be estimated based on the change in light-scattering intensity.

The study of light-scattering intensity on the dew-bubble curve of a binary mixture in the framework of scaling theory

In the framework of scaling theory and the principle of isomorphism of critical phenomena in mixtures, the analytical expression for the light-scattering intensity in a binary fluid mixture has been obtained in rather wide vicinity of its liquid–gas critical point. The deduced validity condition for the light-scattering intensity as an explicit function of temperature or density reveals the adequacy of the description of the obtained experimental data for the methane–pentane binary mixture. The good agreement between the theory and the experiment has been demonstrated. The critical temperature and density values were obtained as a result of optimization procedure.

Association Behavior of Amphiphilic ABA Triblock Copolymer Composed of Poly(2-methoxyethyl acrylate) (A) and Poly(ethylene oxide) (B) in Aqueous Solution

Poly(2-methoxyethyl acrylate) (PMEA) and poly(ethylene oxide) (PEO) have protein-antifouling properties and blood compatibility. ABA triblock copolymers (PMEAn-PEO11340-PMEAn (MEOMn)) were prepared using single-electron transfer-living radical polymerization (SET-LRP) using a bi-functional PEO macroinitiator. Two types of MEOMn composed of PMEA blocks with a degree of polymerization (DP = n) of 85 and 777 were prepared using the same PEO macroinitiator. MEOMn formed flower micelles with a hydrophobic PMEA (A) core and hydrophilic PEO (B) loop shells in diluted water with a similar appearance to petals. The hydrodynamic radii of MEOM85 and MEOM777 were 151 and 108 nm, respectively. The PMEA block with a large DP formed a tightly packed core. The aggregation number (Nagg) of the PMEA block in a single flower micelle for MEOM85 and MEOM777 was 156 and 164, respectively, which were estimated using a light scat-tering technique. The critical micelle concentrations (CMCs) for MEOM85 and MEOM777 were 0.01 and 0.002 g/L, respectively, as determined by the light scattering intensity and fluorescence probe techniques. The size, Nagg, and CMC for MEOM85 and MEOM777 were almost the same inde-pendent of hydrophobic DP of the PMEA block.

Light Scattering as an Easy Tool to Measure Vesicles Weight Concentration

Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the elastic band obtained from a standard spectrofluorimeter. To validate the method, the measured concentrations of vesicles of different matrix compositions and sizes, measured by light scattering with different angles and instruments, were compared to the data obtained by the standard Stewart assay. Consistent results were obtained. The light scattering assay is based on the assessment of the mass fraction lost in the preparation, and can be applied for methods such as extrusion, homogenization, French press and other microfluidic procedures.

Comparative Study of Properties of New Packing Materials Based on Polyvinyl Chloride with Various Additives

New methods is described for assessing the resistance of packaging and other materials to destruction caused by the action of various factors (such as mechanical stress, moisture, and the vital activity of microorganisms etc.). This method include comparing the strength of samples of the studied materials (SSM), determined before and after 9-day incubation of SSM in liquid nutrient medium (NM) with and without test microorganisms (TM) by day-to-day replacement of 40 vol. % NM on steril medium. Resistance to various types of degradation of a number of new polymer materials based on polyvinyl chloride (PVC) with the addition of 0 to 30 mass. % starch, pectin, polyhydroxybutyrate and bentonite was investigated by the method described. The effect of SSM on the growth and metabolic activity in liquid NM of Lactobacillus acidophilus was also studied (according to the dynamics of changes in the elastic light scattering intensity, pH, and electrical conductivity of NM during the first 9 hours of its incubation in the presence of SSM and TM). As a result, it was shown that if it is necessary to increase the overall degradability of such materials (including biodegradability), it is better to use from 5 to 10 mass. % starch as additives to their PVC base. If it is necessary to increase the biodegradability of such materials, it is better to use from 5 to 10 mass. % polyhydroxybutyrate as additives to their PVC base. Аnd if it is necessary to increase the biostability of constructed PVC-materials, it is better to use from 5 to 15 mass .% bentonite as additives to their PVC base.