STUDY OF BETULIN STABILITY BY ELECTROKINETIC POTENTIAL DETERMINATION

Исследование стабильности бетулина методом определения электрокинетического потенциала. На сегодняшний день бетулин интересен в области медицины, косметики и пищевой промышленности, ведь он обладает огромным спектром биологических действий. Из него можно получить производные, которые, в свою очередь, имеют определенное хорошо выраженное действие и используются для производства различных медикаментов. И чтобы интенсифицировать процесс очистки и фильтрования бетулина для экономии времени и затрат на энергию, необходимо узнать его заряд коллоидной частицы и стабильность в водном растворе. Для этого было проведено определение электрокинетического потенциала. Найден ξ-потенциал бетулина в водном растворе, который показал, что с увеличением концентрации водного раствора бетулина вероятность разрушения дисперсии и возможность образования хлопьев при добавлении коагулянта или флогулянта повышаются. Определен заряд поверхности коллоидной частицы бетулина. Investigation of the stability of betulin by the method of determining the electrokinetic potential.Today betulin is interesting in the field of medicine, cosmetics and food industry, because it has a huge range of biological actions. From it, you can get derivatives, which in turn have a certain well-defined effect and are used for the production of various medicines. In order to intensify the process of cleaning and filtering betulin to save time and energy costs, we need to know its colloidal particle charge and stability in an aqueous solution. To do this, we conducted a method for determining the electrokinetic potential. we determined the zeta potential of betulin in an aqueous solution, which showed that with an increase in the concentration of betulin in water, the probability of destruction of the dispersion and the possibility of flocculation when adding a coagulant or flogulant increases. We determined the surface charge of a colloidal betulin particle.

SODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY, PROPERTIES

SODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY PROPERTIES. The α-PbO nanocrystals were successfully decorated using sodium laureth sulfate (SLS) anionic surfactant. The method used is one-pot synthesis approach. The precursor used is lead nitrate (Pb(NO3)2). The UV-Vis spectrophotometer showed the absorption peak of α-PbO nanocrystals was seen at wavelength of 237 nm and an absorbance value of 0.7. The optical properties of PbO nanocrystals can be seen at the bandgap value of 4.2 eV. FT-IR spectroscopy showed the shift of absorption peak at the wavenumber of 1358 cm-1. XRD spectroscopy showed the crystals of PbO at diffraction angles (2θ) of 10-80o: 29.17, 32.54, 37.85, 39.62, 45.16, 46.21, 56.12, and 61.73 with miller indices of (111), (200), (201), (121), (220), (030), (311), and (032), respectively. The crystal size average of PbO was 56.32 nm. The results of PSA and PZC shows the particle size distribution of PbO is 71.5 nm with inter-particle charge of -25 mV. SEM-EDX data shows the PbO nanocrystals have an irregularly spherical with a compounds composition of Pb (83.12%) and O (16.88%). From the data of characterization, it can be concluded the PbO nanocrystals was successfully decorated using the surfactant anionic of sodium laureth sulfate.

Effect of External Charging on Nanoparticle Formation in a Flame

This paper attempts to demonstrate the importance of the nanoparticle charge in the synthesis flame, for the mechanism of their evolution during formation processes. An investigation was made of MgO nanoparticles formed during combustion of magnesium particles. The cubic shape of nanoparticles in an unaffected flame allows for direct interpretation of results on the external flame charging, using a continuous unipolar emission of ions. It was found that the emission of negative ions applied to the flame strongly affects the nanoparticle shape, while the positive ions do not lead to any noticeable change. The demonstrated effect emphasizes the need to take into account all of the phenomena responsible for the particle charge when modeling the nanoparticle formation in flames.

Fractional Coulomb blockade for quasi-particle tunneling between edge channels

In the fractional quantum Hall effect, the elementary excitations are quasi-particles with fractional charges as predicted by theory and demonstrated by noise and interference experiments. We observe Coulomb blockade of fractional charges in the measured magneto-conductance of a 1.4-micron-wide quantum dot. Interaction-driven edge reconstruction separates the dot into concentric compressible regions with fractionally charged excitations and incompressible regions acting as tunnel barriers for quasi-particles. Our data show the formation of incompressible regions of filling factors 2/3 and 1/3. Comparing data at fractional filling factors to filling factor 2, we extract the fractional quasi-particle charge e*/e = 0.32 ± 0.03 and 0.35 ± 0.05. Our investigations extend and complement quantum Hall Fabry-Pérot interference experiments investigating the nature of anyonic fractional quasi-particles.

Publisher Correction: Measuring the α-particle charge radius with muonic helium-4 ions

A Correction to this paper has been published: https://doi.org/10.1038/s41586-021-03360-2.

Comparison of the Effects of the Cationization of Raw, Bio- and Alkali-Scoured Cotton Knitted Fabric with Different Surface Charge Density

Modification of cotton with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) has been studied extensively and can be operated by means of exhaustion, cold pad-batch, and continuous and pad-steam methods. Most of the research addresses the cationization of cotton fabric after bleaching or mercerization, or during the mercerization process. In our studies, we performed a comparison of the cationization effects on raw, enzymatic, and alkali-scoured cotton knitted fabrics applying CHPTAC according to the exhaustion method. The charge density of the cotton surface was measured using a Muetek Particle Charge Detector and a “back titration” method with polyelectrolytes. These results were compared with the nitrogen content in the samples, K/S measurements of tested samples after dyeing with anionic dye (Acid Yellow 194), and other physicochemical parameters such as weight loss, whiteness, and wettability.