Liquid Repellency and Surgical Fabric Barrier Properties

1984 ◽  
Vol 13 (1) ◽  
pp. 35-43 ◽  
Author(s):  
G M Olderman
Keyword(s):  
Comprehensive Evaluation ◽  
Barrier Properties ◽  
Penetration Resistance ◽  
Liquid Penetration ◽  
Test Procedures ◽  
Special Equipment ◽  
Barrier Material ◽  
Barrier Materials ◽  
Word Equation ◽  
Uniform Code

Those who are responsible for controlling the surgical environment require a technically sound, practical, valid, and consistent means of evaluating the barrier properties of surgical drapes and apparel. While many laboratories have, by necessity, agreed upon a limited number of test procedures to evaluate the liquid penetration resistance or repellency of a barrier material, there is no uniform code or guideline that defines the preferred method or methods of evaluation. Assuming wet bacterial transmission through a barrier material is related to the liquid penetration resistance of that material, the following paper attempts to outline the physicochemical basis of repellency in terms of a word equation, define the terminology and relevance to surgical barriers, and suggest the optimum choices of tests from among those in common usage including the group that had been under consideration by the Association for the Advancement of Medical Instrumentation (AAMI) Aseptic Barrier Materials Committee. Because the liquid penetration resistance of a barrier material is a function of both permeability and surface wettability, comprehensive evaluation must include tests for both properties. No single test has been shown to do this reproducibly. Two tests, used by a number of industrial labs, are recommended because, while each test reflects predominantly the degree of either porosity or wetting, together they have been shown to yield information on both properties reliably with results that can be reproduced. These two tests, the fixed liquid pressure test and the dynamic impact test, are simple, non-destructive, and require little special equipment, so they can be performed relatively rapidly on both linens and single-use non-wovens.

scholarly journals Impact of Backbone Amide Substitution at the Meta- and Para-Positions on the Gas Barrier Properties of Polyimide

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2097
Author(s):  
Qian Wen ◽  
Ao Tang ◽  
Chengliang Chen ◽  
Yiwu Liu ◽  
Chunguang Xiao ◽  
...  
Keyword(s):  
Transmission Rate ◽  
Barrier Properties ◽  
Polyimide Film ◽  
Flexible Display ◽  
Gas Barrier ◽  
Positron Annihilation Lifetime ◽  
Barrier Materials ◽  
Oxygen Transmission Rate ◽  
Display Technology ◽  
Gas Barrier Properties

This study designed and synthesised a meta-amide-substituted dianiline monomer (m-DABA) as a stereoisomer of DABA, a previously investigated para-amide-substituted dianiline monomer. This new monomer was polymerised with pyromellitic dianhydride (PMDA) to prepare a polyimide film (m-DABPI) in a process similar to that employed in a previous study. The relationship between the substitution positions on the monomer and the gas barrier properties of the polyimide film was investigated via molecular simulation, wide-angle X-ray diffraction (WXRD), and positron annihilation lifetime spectroscopy (PALS) to gain deeper insights into the gas barrier mechanism. The results showed that compared with the para-substituted DABPI, the m-DABPI exhibited better gas barrier properties, with a water vapour transmission rate (WVTR) and an oxygen transmission rate (OTR) as low as 2.8 g·m−2·d−1 and 3.3 cm3·m−2·d−1, respectively. This was because the meta-linked polyimide molecular chains were more tightly packed, leading to a smaller free volume and lower molecular chain mobility. These properties are not conducive to the permeation of small molecules into the film; thus, the gas barrier properties were improved. The findings have significant implications for the structural design of high-barrier materials and could promote the development of flexible display technology.

scholarly journals Comprehensive Evaluation of Composite Gene Features in Cancer Outcome Prediction

2014 ◽  
Vol 13s3 ◽  
pp. CIN.S14028
Author(s):  
Dezhi Hou ◽  
Mehmet Koyutürk
Keyword(s):  
Outcome Prediction ◽  
Comprehensive Evaluation ◽  
Test Procedures ◽  
Individual Gene ◽  
Cancer Subtypes ◽  
Cancer Types ◽  
Cancer Outcome ◽  
Robust Prediction ◽  
Microarray Datasets ◽  
Gene Feature

Owing to the heterogeneous and continuously evolving nature of cancers, classifiers based on the expression of individual genes usually do not result in robust prediction of cancer outcome. As an alternative, composite gene features that combine functionally related genes have been proposed. It is expected that such features can be more robust and reproducible since they can capture the alterations in relevant biological processes as a whole and may be less sensitive to fluctuations in the expression of individual genes. Various algorithms have been developed for the identification of composite features and inference of composite gene feature activity, which all claim to improve the prediction accuracy. However, because of the limitations of test datasets incorporated by each individual study and inconsistent test procedures, the results of these studies are sometimes conflicting and unproducible. For this reason, it is difficult to have a comprehensive understanding of the prediction performance of composite gene features, particularly across different cancers, cancer subtypes, and cohorts. In this study, we implement various algorithms for the identification of composite gene features and their utilization in cancer outcome prediction, and perform extensive comparison and evaluation using seven microarray datasets covering two cancer types and three different phenotypes. Our results show that, while some algorithms outperform others for certain classification tasks, no single algorithm consistently outperforms other algorithms and individual gene features.

scholarly journals Properties of Whey-Protein-Coated Films and Laminates as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Markus Schmid ◽  
Kerstin Dallmann ◽  
Elodie Bugnicourt ◽  
Dario Cordoni ◽  
Florian Wild ◽  
...  
Keyword(s):  
Whey Protein ◽  
Barrier Layer ◽  
Food Packaging ◽  
Mechanical Load ◽  
Barrier Properties ◽  
Packaging Materials ◽  
Renewable Materials ◽  
Multilayer Material ◽  
Ethylene Vinyl Alcohol ◽  
Barrier Materials

In case of food packaging applications, high oxygen and water vapour barriers are the prerequisite conditions for preserving the quality of the products throughout their whole lifecycle. Currently available polymers and/or biopolymer films are mostly used in combination with barrier materials derived from oil based plastics or aluminium to enhance their low barrier properties. In order to replace these non-renewable materials, current research efforts are focused on the development of sustainable coatings, while maintaining the functional properties of the resulting packaging materials. This article provides an introduction to food packaging requirements, highlights prior art on the use of whey-based coatings for their barriers properties, and describes the key properties of an innovative packaging multilayer material that includes a whey-based layer. The developed whey protein formulations had excellent barrier properties almost comparable to the ethylene vinyl alcohol copolymers (EVOH) barrier layer conventionally used in food packaging composites, with an oxygen barrier (OTR) of <2 [cm³(STP)/(m²d bar)] when normalized to a thickness of 100 μm. Further requirements of the barrier layer are good adhesion to the substrate and sufficient flexibility to withstand mechanical load while preventing delamination and/or brittle fracture. Whey-protein-based coatings have successfully met these functional and mechanical requirements.

Barrier Effect on Electroplated Cu Films

1999 ◽  
Vol 564 ◽  
Author(s):  
R. Faust ◽  
Q. Jiang
Keyword(s):  
Room Temperature ◽  
Copper Films ◽  
Barrier Effect ◽  
Barrier Material ◽  
Dramatic Effect ◽  
Cu Films ◽  
Barrier Materials ◽  
Electroplated Copper

AbstractThe effect of various barrier materials on the microstructure of electroplated Copper films was investigated. Analysis of the Cu was performed at the as-deposited, room temperature stabilized, and annealed states. It shows that the barrier material can have a dramatic effect on the properties of electroplated Cu.

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