Reflectance According to Cell Size, Foaming Ratio and Refractive Index of Microcellular Foamed Amorphous Polymer

Sung Woon Cha; Soo-hyun Cho; Joo Seong Sohn; Youngjae Ryu; Jeonghun Ahn

doi:10.3390/ijms20236068

Reflectance According to Cell Size, Foaming Ratio and Refractive Index of Microcellular Foamed Amorphous Polymer

International Journal of Molecular Sciences ◽

10.3390/ijms20236068 ◽

2019 ◽

Vol 20 (23) ◽

pp. 6068 ◽

Cited By ~ 2

Author(s):

Sung Woon Cha ◽

Soo-hyun Cho ◽

Joo Seong Sohn ◽

Youngjae Ryu ◽

Jeonghun Ahn

Keyword(s):

Refractive Index ◽

Cell Size ◽

Amorphous Polymer ◽

High Specific Surface Area ◽

Polymer Materials ◽

Light Passing ◽

Foaming Process ◽

Microcellular Foaming ◽

Cell Structures ◽

A Cell

Microcellular foamed plastic has a cell size of approximately 0.1 to 10 microns inside a foamed polymer and a cell density in the range of 109 to 1015 cells/cm3. Typically, the formation of numerous uniform cells inside a polymer can be effectively used for various purposes, such as lightweight materials, insulation and sound absorbing materials. However, it has recently been reported that these dense cell structures, which are induced through microcellular foaming, can affect the light passing through the medium, which affects the haze and permeability and causes the diffused reflection of light to achieve high diffuse reflectivity. In this study, the effects of cell size, foaming ratio and refractive index on the optical performance were investigated by applying the microcellular foaming process to three types of amorphous polymer materials. Thus, this study experimentally confirmed that the advantages of porous materials can be implemented as optical properties by providing a high specific surface area as a small and uniform cell formed by inducing a high foaming ratio through a microcellular foaming process.

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Effects of Nanoclay and CO2 Content on Foaming Behaviors of PP/PS Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.898.107 ◽

2014 ◽

Vol 898 ◽

pp. 107-110

Author(s):

Ming Yi Wang ◽

Ru Min Zhu ◽

Nan Qiao Zhou ◽

Chul B. Park

Keyword(s):

Population Density ◽

Cell Size ◽

Cell Population ◽

Foaming Agent ◽

Foaming Process ◽

Microcellular Foaming ◽

Foaming Behavior ◽

Extrusion Foaming

Microcellular foaming behavior of polypropylene/polystyrene (PP/PS) composites with or without the addition of nanoclay was compared in an extrusion foaming process by using supercritical CO2 as the foaming agent. The influence of CO2 content on foaming of the composites was investigated in the study. Our experiment results demonstrated that the introduction of nanoclay dramatically improved the foaming of the PP/PS blends with increased cell-population density and decreased cell size. With the increase of CO2 injected in the foaming process, cell-population density of the foam samples further increased.

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Spindle scaling mechanisms

Essays in Biochemistry ◽

10.1042/ebc20190064 ◽

2020 ◽

Vol 64 (2) ◽

pp. 383-396

Author(s):

Lara K. Krüger ◽

Phong T. Tran

Keyword(s):

Cell Size ◽

Spindle Assembly ◽

Dependent Manner ◽

Post Translational Modification ◽

Size Dependent ◽

A Cell ◽

Chromosome Separation ◽

Spindle Elongation ◽

Protein Gradients ◽

Spindle Structure

Abstract The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.

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Faculty Opinions recommendation of A bacterial effector acts as a plant transcription factor and induces a cell size regulator.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1094879.549818 ◽

2007 ◽

Author(s):

Rino Rappuoli

Keyword(s):

Transcription Factor ◽

Cell Size ◽

A Cell

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Emulsion flow which preparation excludes a presence of mechanical impurities

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2012.2.061 ◽

2012 ◽

Vol 9 (2) ◽

pp. 118-122

Author(s):

A.A. Rakhimov

Keyword(s):

Cell Size ◽

First Case ◽

A Cell ◽

Emulsion Flow ◽

Blocking Mechanism

Experiments were carried out with waterhydrocarbon emulsions with various emulsifiers in capillaries with a length of 2 cm, diameters of 40 and 100 µm. To eliminate the influence of mechanical impurities comparable in size with the diameter of the capillary in first case emulsion components were filtered through fine-meshed filters. In second case obtained that way emulsion was additionally filtered through a system consisting of 3 filters with a cell size of 30-40 microns. In a capillary of 100 µm such emulsion came in a blocked state. Additional filtration of the emulsion through the mesh filters have led to an increase in viscosity but in 100 µm capillaries the time until the blocking 2-3 times more than the original. Rheology of used emulsions is well described by the model of Ostwald-de Waale. It was determined that emulsion blocking mechanism is due to the presence of inclusions not emulsion viscosity.

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Electrically Induced Liquid–Liquid Phase Transition in a Floating Water Bridge Identified by Refractive Index Variations

Water ◽

10.3390/w13050602 ◽

2021 ◽

Vol 13 (5) ◽

pp. 602

Author(s):

Elmar C. Fuchs ◽

Jakob Woisetschläger ◽

Adam D. Wexler ◽

Rene Pecnik ◽

Giuseppe Vitiello

Keyword(s):

Phase Transition ◽

Refractive Index ◽

Liquid Phase ◽

Pure Water ◽

Resonance Effect ◽

Water Bridge ◽

Liquid Phase Transition ◽

Light Passing ◽

Floating Water Bridge ◽

Set Up

A horizontal electrohydrodynamic (EHD) liquid bridge (also known as a “floating water bridge”) is a phenomenon that forms when high voltage DC (kV·cm−1) is applied to pure water in two separate beakers. The bridge, a free-floating connection between the beakers, acts as a cylindrical lens and refracts light. Using an interferometric set-up with a line pattern placed in the background of the bridge, the light passing through is split into a horizontally and a vertically polarized component which are both projected into the image space in front of the bridge with a small vertical offset (shear). Apart from a 100 Hz waviness due to a resonance effect between the power supply and vortical structures at the onset of the bridge, spikes with an increased refractive index moving through the bridge were observed. These spikes can be explained by an electrically induced liquid–liquid phase transition in which the vibrational modes of the water molecules couple coherently.

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Warpage Reduction of Glass Fiber Reinforced Plastic Using Microcellular Foaming Process Applied Injection Molding

Polymers ◽

10.3390/polym11020360 ◽

2019 ◽

Vol 11 (2) ◽

pp. 360 ◽

Cited By ~ 5

Author(s):

Hyun Kim ◽

Joo Sohn ◽

Youngjae Ryu ◽

Shin Kim ◽

Sung Cha

Keyword(s):

Injection Molding ◽

Glass Fiber ◽

Fiber Orientation ◽

Mechanical And Thermal Properties ◽

Micro Ct ◽

Fiber Reinforced ◽

Foaming Process ◽

Microcellular Foaming ◽

Glass Fiber Reinforced ◽

The Impact

This study analyzes the fundamental principles and characteristics of the microcellular foaming process (MCP) to minimize warpage in glass fiber reinforced polymer (GFRP), which is typically worse than that of a solid polymer. In order to confirm the tendency for warpage and the improvement of this phenomenon according to the glass fiber content (GFC), two factors associated with the reduction of the shrinkage difference and the non-directionalized fiber orientation were set as variables. The shrinkage was measured in the flow direction and transverse direction, and it was confirmed that the shrinkage difference between these two directions is the cause of warpage of GFRP specimens. In addition, by applying the MCP to injection molding, it was confirmed that warpage was improved by reducing the shrinkage difference. To further confirm these results, the effects of cell formation on shrinkage and fiber orientation were investigated using scanning electron microscopy, micro-CT observation, and cell morphology analysis. The micro-CT observations revealed that the fiber orientation was non-directional for the MCP. Moreover, it was determined that the mechanical and thermal properties were improved, based on measurements of the impact strength, tensile strength, flexural strength, and deflection temperature for the MCP.

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Higher-order structure of polymer melt described by persistent homology

Scientific Reports ◽

10.1038/s41598-021-80975-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yohei Shimizu ◽

Takanori Kurokawa ◽

Hirokazu Arai ◽

Hitoshi Washizu

Keyword(s):

Cell Size ◽

Md Simulation ◽

Persistent Homology ◽

Polymer Melt ◽

Higher Order ◽

Polymer Materials ◽

Order Structure ◽

Materials Informatics ◽

Optimal Method ◽

Amorphous Nature

AbstractThe optimal method of the polymer Materials Informatics (MI) has not been developed because the amorphous nature of the higher-order structure affects these properties. We have now tried to develop the polymer MI’s descriptor of the higher-order structure using persistent homology as the topological method. We have experimentally studied the influence of the MD simulation cell size as the higher-order structure of the polymer on its electrical properties important for a soft material sensor or actuator device. The all-atom MD simulation of the polymer has been calculated and the obtained atomic coordinate has been analyzed by the persistent homology. The change in the higher-order structure by different cell size simulations affects the dielectric constant, although these changes are not described by a radial distribution function (RDF). On the other hand, using the 2nd order persistent diagram (PD), it was found that when the cell size is small, the island-shaped distribution become smoother as the cell size increased. There is the same tendency for the condition of change in the monomer ratio, the polymer chain length or temperature. As a result, the persistent homology may express the higher-order structure generated by the MD simulation as a descriptor of the polymer MI.

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