DEPOSITION OF DOUBLE-LAYER COATINGS FOR PREPARING COMPOSITE MEMBRANES WITH SUPERHYDROPHOBIC PROPERTIES

PPA–PAN–AA/PAN nanofibrous composite membranes with interfacial polymerization between PIP and TMC based on a PAN–AA/PAN double-layer nanofibrous substrate.

Download Full-text

Thickness Effect on CO2/N2 Separation in Double Layer Pebax-1657®/PDMS Membranes

Membranes ◽

10.3390/membranes8040121 ◽

2018 ◽

Vol 8 (4) ◽

pp. 121 ◽

Cited By ~ 12

Author(s):

Roman Selyanchyn ◽

Miho Ariyoshi ◽

Shigenori Fujikawa

Keyword(s):

Double Layer ◽

Gas Permeability ◽

Composite Membranes ◽

Gas Permeation ◽

Thickness Effect ◽

Organic Polymer ◽

Porous Support ◽

Model Predictions ◽

Layer Membrane ◽

In Series

The effect of thickness in multilayer thin-film composite membranes on gas permeation has received little attention to date, and the gas permeances of the organic polymer membranes are believed to increase by membrane thinning. Moreover, the performance of defect-free layers with known gas permeability can be effectively described using the classical resistance in series models to predict both permeance and selectivity of the composite membrane. In this work, we have investigated the Pebax®-MH1657/PDMS double layer membrane as a selective/gutter layer combination that has the potential to achieve sufficient CO2/N2 selectivity and permeance for efficient CO2 and N2 separation. CO2 and N2 transport through membranes with different thicknesses of two layers has been investigated both experimentally and with the utilization of resistance in series models. Model prediction for permeance/selectivity corresponded perfectly with experimental data for the thicker membranes. Surprisingly, a significant decrease from model predictions was observed when the thickness of the polydimethylsiloxane (PDMS) (gutter layer) became relatively small (below 2 µm thickness). Material properties changed at low thicknesses—surface treatments and influence of porous support are discussed as possible reasons for observed deviations.

Download Full-text

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽

10.32964/tj18.2.93 ◽

2019 ◽

Vol 18 (2) ◽

pp. 93-99

Author(s):

SEYYED MOHAMMAD HASHEMI NAJAFI ◽

DOUGLAS BOUSFIELD, ◽

MEHDI TAJVIDI

Keyword(s):

Mechanical Properties ◽

Double Layer ◽

Starch Content ◽

Single Layer ◽

Double Layers ◽

Coated Paper ◽

Coated Papers ◽

Coating Layers ◽

Scanned Images ◽

Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

Download Full-text

A Survey on Crypto-Steganographic Schemes and A Use Case in Healthcare System

Journal of Engineering Technology and Applied Physics ◽

10.33093/jetap.2019.1.2.6 ◽

2019 ◽

Vol 1 (2) ◽

pp. 25-33

Author(s):

Mei Ling Phang ◽

Swee Huay Heng

Keyword(s):

Social Networking ◽

Information Sharing ◽

Healthcare System ◽

Double Layer ◽

21St Century ◽

Electronic Devices ◽

Third Party ◽

Use Case ◽

Comparison Analysis ◽

Information Assets

Information sharing has become prevalent due to the expansion of social networking in this 21st century. However, electronic devices are vulnerable to various kinds of attacks. Information might be disclosed, modified and accessed by an unauthorised third party which consequently leads to the breach of confidentiality, integrity and availability of the information. Therefore, it is of utmost importance to employ the technology of cryptography and steganography to protect information assets. Cryptography and steganography have weaknesses when they are working alone. Therefore, crypto-steganography, the combination of cryptography and steganography are introduced to overcome the weaknesses in order to provide a double layer of security and protection. This paper provides a general overview of steganography and cryptography as well as a comparison analysis of different crypto-steganographic schemes. A secure crypto-steganographic system for healthcare is then developed with the implementation and integration of the secure crypto-steganographic scheme proposed by Juneja and Sandhu. This healthcare system enables users to store and deliver message in a more secure way while achieving the main goals of both cryptography and steganography.

Download Full-text