The Behavior of Particle Agglomerate in a Newtonian Molten Polymer in the Dispersion and Re-Agglomeration Processes

2008 ◽  
Author(s):  
Yoshiyuki Komoda ◽  
Kanako Kameyama ◽  
Emi Hasegawa ◽  
Hiroshi Suzuki ◽  
Hiromoto Usui ◽  
...  
Keyword(s):  
Molten Polymer ◽  
Particle Agglomerate

scholarly journals Photocatalytic Conversion of Organic Pollutants in Air: Quantum Yields Using a Silver/Nitrogen/TiO2 Mesoporous Semiconductor under Visible Light

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 529
Author(s):  
Adilah Sirivallop ◽  
Salvador Escobedo ◽  
Thanita Areerob ◽  
Hugo de Lasa ◽  
Siriluk Chiarakorn
Keyword(s):  
Visible Light ◽  
Solvothermal Method ◽  
Methanol Conversion ◽  
Quantum Yields ◽  
Tio2 Photocatalyst ◽  
Silver Surface ◽  
Technical Literature ◽  
Volatile Organic ◽  
Irradiation Period ◽  
Particle Agglomerate

This research studies the photocatalytic conversion of methanol (25–90 µmol/L range) as a volatile organic compound (VOC) surrogate into CO2, using a N/Ag/TiO2 photocatalyst under visible light irradiation in a Photo-CREC Air unit. The N/Ag/TiO2 mesh supported photocatalyst is prepared via the solvothermal method. While the bare-TiO2 is inactive under visible light, the N/Ag/TiO2 2 wt.% loaded stainless-steel woven mesh displays 35% quantum yields, with 80% absorbed photons and 60% methanol conversion in a 110 min irradiation period. Results obtained are assigned to silver surface plasmon resonance, silver and nitrogen species synergistic impacts on band gap, and their influence on particle agglomerate size and semiconductor acidity. The determined quantum yields under visible light in a Photo-CREC Air unit, are the highest reported in the technical literature, that these authors are aware of, with this opening unique opportunity for the use of visible light for the purification of air from VOC contaminants.

Non-isothermal flow of a molten polymer in a narrow rectangular cavity

1982 ◽  
Vol 11 (1-2) ◽  
pp. 175-199 ◽  
Author(s):  
H. Van Wijngaarden ◽  
J.F. Dijksman ◽  
P. Wesseling
Keyword(s):  
Isothermal Flow ◽  
Rectangular Cavity ◽  
Molten Polymer

scholarly journals Interface in molten polymer mixtures near the consolute point

1978 ◽  
Vol 39 (9) ◽  
pp. 951-953 ◽  
Author(s):  
J.F. Joanny ◽  
L. Leibler
Keyword(s):  
Polymer Mixtures ◽  
Molten Polymer ◽  
Consolute Point

Theoretical and experimental study of the flow of a molten polymer in a micro‐compounder

2021 ◽  
Author(s):  
Irène Berton ◽  
Romain Castellani ◽  
Lucas Sardo ◽  
Rudy Valette ◽  
Bruno Vergnes
Keyword(s):  
Experimental Study ◽  
Molten Polymer

Rheology of Molten Polymers with Solubilized Gaseous Component

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Bubble Dynamics ◽  
High Pressures ◽  
Polymer Solutions ◽  
Polymer Melts ◽  
Gas Bubbles ◽  
Structural Foam ◽  
Molten Polymer ◽  
Gaseous Component ◽  
Molten Polymers ◽  
Thermoplastic Foam

Polymer melts (or polymer solutions) with a solubilized gaseous component (which occur under sufficiently high pressures, thus forming homogeneous mixtures), and polymer melts (or polymer solutions) with dispersed gas bubbles (thus forming heterogeneous mixtures of polymeric fluid and gas bubbles) are encountered in thermoplastic foam processing and polymer devolatilization. Thus, a good understanding of the rheological behavior of such mixtures is very important to the design of processing equipment and successful optimization of such polymer processing operations. From the 1950s through the 1970s, the dynamics of a single, spherical gas bubble dispersed in a stationary Newtonian or viscoelastic medium was extensively reported in the literature (Barlow and Langlois 1962; Duda and Vrentas 1969; Epstein and Plesset 1950; Folger and Goddard 1970; Marique and Houghton 1962; Plessst and Zwick 1952; Rosner and Epstein 1972; Ruckenstein and Davis 1970; Scriven 1959; Street 1968; Street et al. 1971; Tanasawa and Yang 1970; Ting 1975; Yang and Yeh 1966; Yoo and Han 1982; Zana and Leal 1975). While such investigations are of fundamental importance in their own right, they are not much help to describe bubble dynamics in thermoplastic foam extrusion or structural foam injection molding, for instance. There is no question that an investigation of bubble dynamics in a flowing molten polymer with dispersed gas bubbles is a very difficult subject by any measure. Thus, understandably, a relatively small number of research publications on bubble dynamics in a flowing molten polymer have been reported (Han and Villamizar 1978; Han et al. 1976; Yoo and Han 1981). The complexity of the problem arises from other related issues, such as the solubility and diffusivity of gaseous component(s) in a flowing molten polymer, which in turn depend on temperature and pressure of the system. Further, a gaseous component solubilized in molten polymer in the upstream side of a die, for instance, may nucleate as the pressure of the fluid stream decreases along the die axis, after which they could grow continuously as the molten polymer with dispersed gas bubbles flows through the rest of the die.

scholarly journals Nanocomposite of Poly(l-Lactic Acid) with Inorganic Nanotubes of WS2

Lubricants ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 28 ◽  
Author(s):  
Hila Shalom ◽  
XiaoMeng Sui ◽  
Olga Elianov ◽  
Vlad Brumfeld ◽  
Rita Rosentsveig ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Considerable Increase ◽  
Complex Viscosity ◽  
Inorganic Nanotubes ◽  
Molten Polymer ◽  
X Ray ◽  
Mechanical And Tribological Properties ◽  
Surface Active Agents ◽  
Surface Active ◽  
Surface Modified

Composites of poly(l-lactic acid) (PLLA) reinforced by adding inorganic nanotubes of tungsten disulfide (INT–WS2) were prepared by solvent casting. In addition to the pristine nanotubes, PLLA nanocomposites containing surface modified nanotubes were studied as well. Several surface-active agents, including polyethylene imine (PEI), were studied in this context. In addition, other biocompatible polymers, like poly d,l-lactic acid (PDLLA) and others were considered in combination with the INT–WS2. The nanotubes were added to the polymer in different proportions up to 3 wt %. The dispersion of the nanotubes in the nanocomposites were analyzed by several techniques, including X-ray tomography microscopy (Micro-XCT). Moreover, high-temperature rheological measurements of the molten polymer were conducted. In contrast to other nanoparticles, which lead to a considerable increase of the viscosity of the molten polymer, the WS2 nanotubes did not affect the viscosity significantly. They did not affect the complex viscosity of the molten PLLA phase, either. The mechanical and tribological properties of the nanocomposites were found to improve considerably by adding the nanotubes. A direct correlation was observed between the dispersion of the nanotubes in the polymer matrix and its mechanical properties.

Effect of engine operating conditions on soot layer permeability and density in diesel particulate filters

2019 ◽  
Vol 22 (1) ◽  
pp. 50-63
Author(s):  
Christian Zöllner ◽  
Onoufrios Haralampous ◽  
Dieter Brüggemann
Keyword(s):  
Flow Rate ◽  
Large Particle ◽  
Operating Conditions ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Agglomerate Size ◽  
Diesel Particulate Filters ◽  
Particulate Filters ◽  
Operating Points ◽  
Particle Agglomerate

Understanding the variation of soot deposit properties in diesel particulate filters is necessary for their real-life modeling and onboard control. In this study, the effect of exhaust mass flow rate and particle agglomerate size on the soot layer permeability and density was investigated experimentally and analyzed using a well-validated model. A bare and a coated diesel particulate filter were loaded at five different engine operating points, specially selected to explore these effects in a heavily used part of the diesel engine map. Particle emissions were characterized in terms of particle agglomerate size distribution and primary particle diameter, while soot layer permeability and density were estimated indirectly by fitting the model to the pressure drop recordings. To this end, an automatic calibration procedure was applied to obtain values in a consistent and repeatable manner. The results showed considerable variation in both permeability and density. Furthermore, some trends could be identified after depicting the particle characterization data and soot layer properties in contour plots. Increased permeability appeared at the engine operating point with high flow rate and large particle agglomerate size. Lower density was obtained at the operating points with large particle agglomerate diameter.

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