Ultrathin Free-Standing Polyelectrolyte Nanocomposites:  A Novel Method for Preparation and Characterization of Assembly Dynamics

2005 ◽  
Vol 109 (31) ◽  
pp. 14764-14768 ◽  
Author(s):  
James K. Ferri ◽  
Wen-Fei Dong ◽  
Reinhard Miller
Keyword(s):  
Free Standing ◽  
Novel Method

Mechanics of free-standing inorganic and molecular 2D materials

Nanoscale ◽  
2021 ◽  
Author(s):  
Xianghui Zhang ◽  
Andre Beyer
Keyword(s):  
Recent Progress ◽  
Mechanical Characterization ◽  
2D Materials ◽  
Two Dimensional ◽  
Free Standing ◽  
Inorganic As

The discovery of graphene has triggered a great interest in inorganic as well as molecular two-dimensional (2D) materials. In this review, we summarize recent progress in the mechanical characterization of...

scholarly journals Creation of Ionically Crosslinked Tri-Layered Chitosan Membranes to Simulate Different Human Skin Properties

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1807
Author(s):  
Rocío Guerle-Cavero ◽  
Blanca Lleal-Fontàs ◽  
Albert Balfagón-Costa
Keyword(s):  
Elastic Modulus ◽  
Human Skin ◽  
Sodium Tripolyphosphate ◽  
Snow Crab ◽  
Suitable Material ◽  
Cosmetic Industry ◽  
Novel Method ◽  
Current Article ◽  
Chitosan Membranes

In 2023, new legislation will ban the use of animals in the cosmetic industry worldwide. This fact, together with ethical considerations concerning the use of animals or humans in scientific research, highlights the need to propose new alternatives for replacing their use. The aim of this study is to create a tri-layered chitosan membrane ionically crosslinked with sodium tripolyphosphate (TPP) in order to simulate the number of layers in human skin. The current article highlights the creation of a membrane where pores were induced by a novel method. Swelling index, pore creation, and mechanical property measurements revealed that the swelling index of chitosan membranes decreased and, their pore formation and elasticity increased with an increase in the Deacetylation Grade (DDA). Additionally, the results demonstrate that chitosan’s origin can influence the elastic modulus value and reproducibility, with higher values being obtained with seashell than snow crab or shrimp shells. Furthermore, the data show that the addition of each layer, until reaching three layers, increases the elastic modulus. Moreover, if layers are crosslinked, the elastic modulus increases to a much greater extent. The characterization of three kinds of chitosan membranes was performed to find the most suitable material for studying different human skin properties.

Polycrystalline Silicon Gettering Layers with Controlled Residual Stress

2013 ◽  
Vol 205-206 ◽  
pp. 284-289 ◽  
Author(s):  
David Lysáček ◽  
Petr Kostelník ◽  
Petr Pánek
Keyword(s):  
Residual Stress ◽  
Vapor Deposition ◽  
Polycrystalline Silicon ◽  
Opposite Sign ◽  
Chemical Vapor ◽  
Pressure Chemical ◽  
Novel Method ◽  
The Individual ◽  
Scanning Electron

We report on a novel method of low pressure chemical vapor deposition of polycrystalline silicon layers used for external gettering in silicon substrate for semiconductor applications. The proposed method allowed us to produce layers of polycrystalline silicon with pre-determined residual stress. The method is based on the deposition of a multilayer system formed by two layers. The first layer is intentionally designed to have tensile stress while the second layer has compressive stress. Opposite sign of the residual stresses of the individual layers enables to pre-determine the residual stress of the gettering stack. We used scanning electron microscopy for structural characterization of the layers and intentional contamination for demonstration of the gettering properties. Residual stress of the layers was calculated from the wafer curvature.

Characterization of free standing GaN grown by HVPE on a LiAlO2substrate

2006 ◽  
Vol 203 (7) ◽  
pp. 1663-1666 ◽  
Author(s):  
Lijun Wang ◽  
U. Zeimer ◽  
E. Richter ◽  
Ch. Hennig ◽  
M. Herms ◽  
...  
Keyword(s):  
Free Standing

Graphite/UPE Nanocomposite: Transport, Thermal, Mechanical and Viscoelastic Properties

2019 ◽  
Vol 23 ◽  
pp. 201-212
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia
Keyword(s):  
Transport Properties ◽  
Unsaturated Polyester ◽  
Homogeneous Distribution ◽  
Thermo Gravimetric ◽  
New Class ◽  
The Matrix ◽  
Novel Method ◽  
Water Transport Properties ◽  
First Time

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.

scholarly journals Regiodivergent Biocatalytic Hydroxylation of L-Glutamine Facilitated by Characterization of Non-Heme Dioxygenases from Non-Ribosomal Peptide Biosyntheses

2021 ◽  
Author(s):  
Hans Renata ◽  
Emily Shimizu ◽  
Christian Zwick
Keyword(s):  
Amino Acid ◽  
Building Block ◽  
Solid Phase ◽  
Functional Characterization ◽  
Free Standing ◽  
Substrate Specificities ◽  
Total Turnover

We report the functional characterization of two iron- and a-ketoglutarate-dependent dioxygenases that are capable of hydroxylating free-standing glutamine at its C3 and C4 position respectively. In particular, the C4 hydroxylase, Q4Ox, catalyzes the reaction with approximately 4,300 total turnover numbers, facilitating synthesis of a solid-phase compatible building block and stereochemical elucidation at the C4 position of the hydroxylated product. This work will enable the development of novel synthetic strategies to prepare useful glutamine derivatives and stimulate further discoveries of new amino acid hydroxylases with distinct substrate specificities.<br>

scholarly journals Regiodivergent Biocatalytic Hydroxylation of L-Glutamine Facilitated by Characterization of Non-Heme Dioxygenases from Non-Ribosomal Peptide Biosyntheses

2021 ◽  
Author(s):  
Hans Renata ◽  
Emily Shimizu ◽  
Christian Zwick
Keyword(s):  
Amino Acid ◽  
Building Block ◽  
Solid Phase ◽  
Functional Characterization ◽  
Free Standing ◽  
Substrate Specificities ◽  
Total Turnover

We report the functional characterization of two iron- and a-ketoglutarate-dependent dioxygenases that are capable of hydroxylating free-standing glutamine at its C3 and C4 position respectively. In particular, the C4 hydroxylase, Q4Ox, catalyzes the reaction with approximately 4,300 total turnover numbers, facilitating synthesis of a solid-phase compatible building block and stereochemical elucidation at the C4 position of the hydroxylated product. This work will enable the development of novel synthetic strategies to prepare useful glutamine derivatives and stimulate further discoveries of new amino acid hydroxylases with distinct substrate specificities.<br>

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