Rapid Formation of a Lamellar Structure in an Amphiphilic Comb‐Shaped Polymer by Nanophase Separation Using Microwave–Humidity Annealing

2021 ◽  
pp. 2100404
Author(s):  
Mizuki Ohke ◽  
Jun Matsui
Keyword(s):  
Lamellar Structure ◽  
Rapid Formation ◽  
Nanophase Separation

EFFECTS OF UNTWINNING AND {1012} TWIN LAMELLAR STRUCTURE ON THE MECHANICAL PROPERTIES OF Mg ALLOY

2013 ◽  
Vol 49 (3) ◽  
pp. 291 ◽  
Author(s):  
Chao LOU ◽  
Xiyan ZHANG ◽  
Runhong WANG ◽  
Gaolin DUAN ◽  
Qing LIU
Keyword(s):  
Mechanical Properties ◽  
Lamellar Structure ◽  
Mg Alloy

Melting and Crystallization of Poly(oxyethylene) Mixtures

1995 ◽  
Vol 60 (11) ◽  
pp. 1855-1868 ◽  
Author(s):  
Ivo Lapeš ◽  
Josef Baldrian ◽  
Ján Biroš ◽  
Julius Pouchlý ◽  
Hanes Mio
Keyword(s):  
Melting Point ◽  
Lamellar Structure ◽  
Composition Dependence ◽  
Eutectic Phase ◽  
Eutectic Melting ◽  
Pure Polymer ◽  
X Ray ◽  
Long Period ◽  
Solid Liquid ◽  
Melting And Crystallization

Solid-liquid eutectic phase diagrams of mixtures of poly(oxyethylene) (M.w. 2 000) with hydroxy and methoxy endgroups, crystallizing in extended-chain macroconformation only, with glutaric acid, benzoic acid or 1,2-diphenylethane are given. The composition dependence of the melting temperature can be fitted by the Flory-Huggins equation. Interaction parameters X and interaction energy densities B evaluated from the diluent branch of the phase diagram are consistent with those obtained from the polymer branch provided the calorimetric value of enthalpy of polymer fusion is used in the latter computation. Measurements of small- and wide-angle X-ray scatterings showed a stacked lamellar structure of POE. Below the eutectic melting point, the long period of the polymer is almost independent of the diluent concentration. On raising temperature gradually from this melting point to the melting point of pure polymer, the increasing long period indicates the penetration of the diluent between the lamellae. As follows from SAXS measurements, the crystallinity of poly(oxyethylene) in the mixtures remains unchanged compared to that of the pure polymer.

scholarly journals Ripple Formation during Oblique Angle Etching

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 272
Author(s):  
Mehmet F. Cansizoglu ◽  
Mesut Yurukcu ◽  
Tansel Karabacak
Keyword(s):  
Plasma Etching ◽  
Incidence Angle ◽  
Incident Beam ◽  
Root Mean Square Roughness ◽  
Sticking Coefficient ◽  
Oblique Angle ◽  
Nano Fabrication ◽  
Ripple Formation ◽  
Rapid Formation ◽  
Roughness Analysis

Chemical removal of materials from the surface is a fundamental step in micro- and nano-fabrication processes. In conventional plasma etching, etchant molecules are non-directional and perform a uniform etching over the surface. However, using a highly directional obliquely incident beam of etching agent, it can be possible to engineer surfaces in the micro- or nano- scales. Surfaces can be patterned with periodic morphologies like ripples and mounds by controlling parameters including the incidence angle with the surface and sticking coefficient of etching particles. In this study, the dynamic evolution of a rippled morphology has been investigated during oblique angle etching (OAE) using Monte Carlo simulations. Fourier space and roughness analysis were performed on the resulting simulated surfaces. The ripple formation was observed to originate from re-emission and shadowing effects during OAE. Our results show that the ripple wavelength and root-mean-square roughness evolved at a more stable rate with accompanying quasi-periodic ripple formation at higher etching angles (θ > 60°) and at sticking coefficient values (Sc) 0.5 ≤ Sc ≤ 1. On the other hand, smaller etching angle (θ < 60°) and lower sticking coefficient values lead to a rapid formation of wider and deeper ripples. This result of this study can be helpful to develop new surface patterning techniques by etching.

scholarly journals Gold nanoparticles grafted with chemically incompatible ligands

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9568-9571
Author(s):  
Joanna M. Wolska ◽  
Aleksandra Błażejewska ◽  
Martyna Tupikowska ◽  
Damian Pociecha ◽  
Ewa Górecka
Keyword(s):  
Gold Nanoparticles ◽  
Lamellar Structure

A Janus-type lamellar structure is formed from gold nanoparticles grafted with chemically incompatible mesogenic ligands. Metallic NP-rich sublayers are separated by ligand-rich sublayers of various composition due to the ligand segregation.

scholarly journals Rapid Formation of Stem Cell Spheroids Using Two-Dimensional MXene Particles

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 957
Author(s):  
JunHwee Jang ◽  
Eun-Jung Lee
Keyword(s):  
Stem Cell ◽  
Mass Production ◽  
Processing Time ◽  
Activity Levels ◽  
Two Dimensional ◽  
Spheroid Formation ◽  
Cell Spheroids ◽  
Tissue Healing ◽  
Rapid Formation ◽  
Cell Sources

Cell spheroids have been studied as a biomimic medicine for tissue healing using cell sources. Rapid cell spheroid production increases cell survival and activity as well as the efficiency of mass production by reducing processing time. In this study, two-dimensional MXene (Ti3C2) particles were used to form mesenchymal stem cell spheroids, and the optimal MXene concentration, spheroid-production times, and bioactivity levels of spheroid cells during this process were assessed. A MXene concentration range of 1 to 10 μg/mL induced spheroid formation within 6 h. The MXene-induced spheroids exhibited osteogenic-differentiation behavior, with the highest activity levels at a concentration of 5 μg/mL. We report a novel and effective method for the rapid formation of stem cell spheroids using MXene.

Membrane Alterations Induced by Amphiphiles

1989 ◽  
Vol 16 (3) ◽  
pp. 274-280
Author(s):  
Boris Isomaa ◽  
Henry Hägerstrand ◽  
Gun I.L. Paatero
Keyword(s):  
Ion Transport ◽  
Lipid Bilayer ◽  
Erythrocyte Membrane ◽  
Cell Shape ◽  
Osmotic Fragility ◽  
Molecular Shape ◽  
Specific Interactions ◽  
Amphiphilic Compounds ◽  
Rapid Formation ◽  
Polar Parts

Amphiphilic compounds with distinct apolar and polar parts are readily intercalated into the erythrocyte membrane. When intercalated into the membrane, amphiphiles are probably orientated so that the polar head is at the polar-apolar interface of the lipid bilayer and the hydrophobic part within the apolar core of the bilayer. However, by virtue of their difference in molecular shape from the bulk lipids of the lipid bilayer, it is possible that the intercalated amphiphiles are partly segregated from bulk lipids and accumulate at protein-lipid interfaces in the bilayer, where the packing of the bilayer lipids may be less ordered. Our studies show that amphiphiles, when intercalated into the erythrocyte membrane, trigger alterations in several membrane-connected functions. Some of the alterations induced (decreased osmotic fragility, increased passive potassium fluxes) seem to be due to non-specific interactions of the amphiphiles with the membrane, whereas other functions (ion transport mediated by membrane proteins, regulation of cell shape) seem to be sensitive to particular features of the amphiphiles. Our studies indicate that the intercalation of amphiphiles into the erythrocyte membrane must involve rearrangements within the lipid bilayer. We have suggested that, when intercalated into the lipid bilayer, amphiphiles trigger a rapid formation of non-bilayer phases, which protect the bilayer against a collapse and bring about a trans-bilayer redistribution of intercalated amphiphiles as well as of bilayer lipids. At high sublytic concentrations, this process may also involve a release of microvesicles from the membrane.

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