Abstract Although microplastics are ubiquitous in today’s natural environments, our understanding of the materials, quantities, and particle sizes involved remains limited. The recovery from different types environmental matrices requires standardized matrix digestion protocols that allow inter-laboratory comparisons have no effect on polymers themselves. A number commonly used methods rely oxidation with concentrated hydrogen peroxide solutions to remove organic matter matrix. However, this...

Understanding the occurrence and transformation of microplastics when released into environment is essential for risk assessment. The use biodegradable polymers in agriculture can help to reduce microplastic accumulation soil, since fragments such materials are not persistent further transformed CO2 biomass (Wohlleben et al., 2023). To be able monitor fragmentation biodegradation these a validated extraction protocol needed, which does induce changes chemical particle properties,...

Abstract Silica‐like nanoparticles are produced from four different organosilicon monomers HMDSO, TMDSO, TEOS and TMOS in a continuous non‐equilibrium plasma reactor. The nanoparticle synthesis is studied as function of the process pressure, power, gas velocity,and composition (Ar:O 2 :monomer). morphology, mass production,and chemical formed particlesare investigated. An adapted particle growth model for reactor introduced which explains influence parameters on evolution. morphology...

The moisture transport in fabrics determines its cooling effect and therefore the wearing comfort during sudorific activities. When liquid sweat is present, absorption by a fabric characterized in-plane transplanar wicking. We investigated of structure fiber count on wicking X-ray projection images using four different polyester knit structures (rib, eyelet, interlock modified interlock, all hydrophilic), as well five rib knits with counts per yarn (24–192, quasi-hydrophobic water contact...

The surface activation of high-density polyethylene powder using a remote plasma process at atmospheric pressure is investigated. developed circulating fluidized bed reactor enables to carry fine-grained particles repetitively through the afterglow 64 dielectric barrier discharges argon with O2 and CO2 admixtures. evolution particle size distribution during conveying in monitored by laser diffraction reveals that only small fraction lost process. contact angle activated samples steadily...

Abstract The surface of fine lactose powder particulates was modified by direct‐plasma exposure in a radio frequency (RF) discharge, mixture oxygen and hexamethyldisiloxane (HMDSO) diluted argon. Besides, the RF power (100–500 W) HMDSO flow rate (0–68 sccm) at constant oxygen‐to‐HMDSO ratio 10 varied this study. Apart from relatively high pressure 2 mbar, plasma process adopted is very much alike enhanced chemical vapor deposition silica‐like material descending plasma‐chemical reaction...

Cold model investigations were performed into bottom blowing involving two-phase and three-phase systems. The – with interrelated variation of the test parameters: nozzle arrangement, number nozzles, eccentricity rate, geometry reactor addition a slag simulation phase reveal series specific vortex patterns in bath. most favourable overall degree mixing is achieved an eccentric triangular arrangement nozzles. Increasing nozzles on one hand, spacing further apart other, improves flow...

Abstract The tubular plasma reactor was designed for the continuous surface modification of fine powders in non-equilibrium RF discharges. So far, little has been known about characteristics this inductively coupled system. Therefore, moderate pressure argon–oxygen discharges, commonly used powder processing, are investigated with tailor-made probe techniques. influence power, system pressure, gas composition and mean velocity on axial profiles parameters studied. Electron temperature...

Abstract A plasma downstream reactor for the continuous treatment of dry, cohesive, and temperature sensitive powders is investigated by means fiber optic measurements. method to determine different heat flux terms (plasma heating, radiation, convection) introduced applied calculate inner wall neutral gas at several positions within reactor. By this undesirable discharge regions zone are found. Consequently, thermal characterization allows optimization design confine downer tube avoid hot spots.

The energy influx in a non-equilibrium plasma the afterglow of downstream reactor has been measured by two different calorimetric probe types. radio frequency discharge is investigated for oxygen (10–100%)–argon (90–0%) mixtures at relatively high gas flow rates (750–3000 sccm) and pressures (100–350 Pa). main process parameters influencing are power, system pressure total rate. Even though size, geometry material composition used types different, comparable flux values achieved. Depending...

A dielectric barrier discharge containing argon and oxygen is used to dissociate HMDSO with the purpose of producing silica‐like particles. Solid material deposited in an electrostatic precipitator analyzed SEM, FTIR, weight measurements. The variation concentration shows optimum for particle yield at oxygen‐to‐monomer ratio 20. Increasing nanoparticle formation are also found increasing excitation frequency explained corresponding higher power input survival rates from aerosol theory....

The flowability of micropowders can be improved by depositing a non‐continuous coating on the micropowder surface, which reduces interparticle van der Waals forces causing cohesion native powder. Such achieved via plasma enhanced chemical vapor deposition in tubular, inductively‐coupled RF glow‐discharge‐plasma reactor fed plasma‐polymerizable gases. Here we systematically study influence user‐set parameters feed gas flow rate and power resulting powder flowability. We find quasi‐Arrhenius...

Cold model investigations were performed during top and combined blowing in metallurgical processes. The include 2‐ 3‐phase systems with gas, water oil phase. results of tests can be used to arrange optimise the fluid flow. Further, conclusions drawn for spraying emulsification process, if slag thickness is known. Under conditions a small amount stirring gas injected from bottom has great influence on mixing. According thickness, combination power momentum, flow dominated by or blowing. If...

For the first time, an atmospheric‐pressure plasma process is presented that enables continuous flowability improvement of cohesive, temperature‐sensitive, and fine‐grained powder. this, atmospheric pressure dielectric barrier discharge operating with argon oxygen used to dissociate HMDSO form nanoparticles. The nanoparticles are directly deposited on surface cohesive lactose These decrease distance‐dependent attractive van der Waals forces in between particles therefore, improve its...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTField Kit for Estimating Moisture in Acrylic Molding Powder by Small Sealed Vessel TechniqueC. F. Roth and John. MitchellCite this: Anal. Chem. 1956, 28, 9, 1502–1504Publication Date (Print):August 21, 1956Publication History Published online1 May 2002Published inissue 21 August 1956https://doi.org/10.1021/ac60117a051RIGHTS & PERMISSIONSArticle Views9Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full...

Treatment time-dependent contact angles of polyethylene samples activated in the afterglow a dielectric barrier discharge are investigated. A semi-empirical model is proposed describing angle behavior by two simultaneously occurring exponential decay processes. Fitted parameters used to examine influence thickness, gas flow rate and electrode length on decay. Results reveal faster decrease with reduced thickness higher rate. The each activation process varies when changed. different speed...

Cold model investigations were performed in two and three phase systems, including water-, slag- gas-phase. The following nozzle-arrangements chosen: single central nozzle, centric row, eccentric row triangle. show an intensive vortex formation the bath as a result of coupled variation parameters like blowing rate existence slag simulation phase. A clear-cut is evident at undercritical rate. buoyant free jets do not describe stable path to surface. Two liquid zones with mutually distinct...

AbstractThe triple-helical content of gelatin measured in dilute solution correlates with the brittleness its cold-dried layer. The layer is low and, accordingly, elasticity high for a small and vice versa. This effect discussed on basis moisture Triple-helical domains contain part it as "structural" water. residue "layer" water which determines