scholarly journals The role of interlayer adhesion in graphene oxide upon its reinforcement of nanocomposites

2016 ◽  
Vol 374 (2071) ◽  
pp. 20150283 ◽  
Author(s):  
Zheling Li ◽  
Ian A. Kinloch ◽  
Robert J. Young
Keyword(s):  
Graphene Oxide ◽  
Structural Integrity ◽  
Mechanical Reinforcement ◽  
Graphene Lattice ◽  
The Matrix ◽  
Observed Behaviour ◽  
Reinforcement Efficiency ◽  
Intrinsic Stiffness ◽  
High Degree

Graphene oxide (GO) has become a well-established reinforcement for polymer-based nanocomposites. It provides stronger interfacial interaction with the matrix when compared with that of graphene, but its intrinsic stiffness and strength are somewhat compromised because of the presence of functional groups damaging the graphene lattice and increasing its thickness, and its tendency to adopt a crumpled structure. Although the micromechanics of graphene reinforcement in nanocomposites has been studied widely, the corresponding micromechanics investigations on GO have not been undertaken in such detail. In this work, it is shown that the deformation micromechanics of GO can be followed using Raman spectroscopy and the observed behaviour can be analysed with continuum mechanics. Furthermore, it is shown that the reinforcement efficiency of GO is independent of its number of layers and stacking configurations, indicating that it is not necessary to ensure a high degree of exfoliation of GO in the polymer matrix. It also demonstrates the possibility of increasing the concentration of GO in nanocomposites without sacrificing mechanical reinforcement efficiency. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

Nucleation Ability of Thermally Reduced Graphene Oxide for Polylactide: Role of Size and Structural Integrity

2015 ◽  
Vol 119 (13) ◽  
pp. 4777-4787 ◽  
Author(s):  
Yuan-Ying Liang ◽  
Su Yang ◽  
Xin Jiang ◽  
Gan-Ji Zhong ◽  
Jia-Zhuang Xu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Structural Integrity ◽  
Reduced Graphene

scholarly journals Understanding the Matrix: The Role of Extracellular DNA in Oral Biofilms

2021 ◽  
Vol 2 ◽  
Author(s):  
Hannah J. Serrage ◽  
Mark A. Jepson ◽  
Nadia Rostami ◽  
Nicholas S. Jakubovics ◽  
Angela H. Nobbs
Keyword(s):  
Dental Plaque ◽  
Molecular Mechanisms ◽  
Structural Integrity ◽  
Extracellular Dna ◽  
Oral Disease ◽  
Diverse Range ◽  
Oral Biofilms ◽  
The Matrix ◽  
Plaque Biofilm

Dental plaque is the key etiological agent in caries formation and the development of the prevalent chronic oral inflammatory disease, periodontitis. The dental plaque biofilm comprises a diverse range of microbial species encased within a rich extracellular matrix, of which extracellular DNA (eDNA) has been identified as an important component. The molecular mechanisms of eDNA release and the structure of eDNA have yet to be fully characterized. Nonetheless, key functions that have been proposed for eDNA include maintaining biofilm structural integrity, initiating adhesion to dental surfaces, acting as a nutrient source, and facilitating horizontal gene transfer. Thus, eDNA is a potential therapeutic target for the management of oral disease–associated biofilm. This review aims to summarize advances in the understanding of the mechanisms of eDNA release from oral microorganisms and in the methods of eDNA detection and quantification within oral biofilms.

scholarly journals Key Role of the Dispersion of Carbon Nanotubes (CNTs) within Epoxy Networks on their Ability to Release

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2530
Author(s):  
Maxime Pras ◽  
Jean-François Gérard ◽  
Luana Golanski ◽  
Guilhem Quintard ◽  
Jannick Duchet-Rumeau
Keyword(s):  
Polymer Matrix ◽  
Interfacial Strength ◽  
Advanced Materials ◽  
Mechanical Reinforcement ◽  
Rheological Analysis ◽  
Polymerization Kinetic ◽  
The Matrix ◽  
Dispersion State ◽  
The Relationship

Carbon nanotube (CNT)-reinforced nanocomposites represent a unique opportunity in terms of designing advanced materials with mechanical reinforcement and improvements in the electrical and thermal conductivities. However, the toxic effects of these composites on human health have been studied, and very soon, some regulations on CNTs and on composites based on CNTs will be enacted. That is why the release of CNTs during the nanocomposite lifecycle must be controlled. As the releasing depends on the interfacial strength that is stronger between CNTs and polymers compared to CNTs in a CNT agglomerate, two dispersion states—one poorly dispersed versus another well dispersed—are generated and finely described. So, the main aim of this study is to check if the CNT dispersion state has an influence on the CNT releasing potential in the nanocomposite. To well tailor and characterize the CNT dispersion state in the polymer matrix, electronic microscopies (SEM and TEM) and also rheological analysis are carried out to identify whether CNTs are isolated, in bundles, or in agglomerates. When the dispersion state is known and controlled, its influence on the polymerization kinetic and on mechanical properties is discussed. It appears clearly that in the case of a good dispersion state, strong interfaces are generated, linking the isolated nanotubes with the polymer, whereas the CNT cohesion in an agglomerate seems much more weak, and it does not provide any improvement to the polymer matrix. Raman spectroscopy is relevant to analyze the interfacial properties and allows the relationship with the releasing ability of nanocomposites; i.e., CNTs poorly dispersed in the matrix are more readily released when compared to well-dispersed nanocomposites. The tribological tests confirm from released particles granulometry and observations that a CNT dispersion state sufficiently achieved in the nanocomposite avoids single CNT releasing under those solicitations.

scholarly journals Experimental study of the three-dimensional flow structure in matrix channels

2021 ◽  
Vol 2057 (1) ◽  
pp. 012027
Author(s):  
M V Philippov ◽  
I A Chokhar ◽  
A V Zolotukhin ◽  
A V Barsukov ◽  
V V Terekhov ◽  
...  
Keyword(s):  
Experimental Study ◽  
Three Dimensional ◽  
Decisive Role ◽  
Three Dimensional Flow ◽  
Matrix Channel ◽  
Dimensional Flow ◽  
The Matrix ◽  
Role Based ◽  
High Degree

Abstract The article presents an experimental study of the turbulent flow in matrix channels. Using the modern optical contactless laser Doppler anemometer (LDA) method, an idea of the turbulent three-dimensional flow inside the cells of matrix channels is developed. The results of the study of the matrix channel show that the so-called vortex matrix effect is not formed. The most important factor that causes a high degree of heat transfer from the walls is the intense spiral motion between the matrix cells. The measurements also show that the effects associated with the lateral boundaries of the channel play a significant role. Based on the assumption of the decisive role of the spiral flow between the cells of the matrix channel, a formula for the integral pressure loss is proposed.

Role of graphene oxide on the tribological properties of CF reinforcement high strength glass fabric/phenolic laminate composites in water environment

2020 ◽  
Vol 72 (7) ◽  
pp. 873-879
Author(s):  
Fengxiang Cao ◽  
Fengyuan Yan ◽  
Jianzhang Wang
Keyword(s):  
Graphene Oxide ◽  
Peer Review ◽  
Tribological Properties ◽  
Water Environment ◽  
High Strength ◽  
Glass Fabric ◽  
Laminate Composites ◽  
Content Type ◽  
The Matrix

Purpose This paper aims to study the tribological properties of high strength glass fabric/phenolic laminate composites reinforced by carbon fiber (CF) with and without graphene oxide (GO) modified. Design/methodology/approach In this study, the tribological performance tests of the composites were conducted on a block-on-ring tester (MRH-03). The applied load, linear velocity and duration of time are 200 N, 0.5 m/s and 120 min, respectively. The friction coefficient and specific wear rate were shown. Findings The optimal content of GO on CFs is 0.2 per cent mass fraction. The optimal content of GO addition means the strongest interfacial adhesion between the CF and the matrix. Originality/value The main originality of this paper is to reveal the effect of surface GO on CF on the tribological properties of fabric-reinforced composites. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0273/

Extracellular matrix: the gatekeeper of tumor angiogenesis

2019 ◽  
Vol 47 (5) ◽  
pp. 1543-1555 ◽  
Author(s):  
Maurizio Mongiat ◽  
Simone Buraschi ◽  
Eva Andreuzzi ◽  
Thomas Neill ◽  
Renato V. Iozzo
Keyword(s):  
Extracellular Matrix ◽  
Tumor Angiogenesis ◽  
Signaling Cascades ◽  
Cancer Growth ◽  
Cell Behavior ◽  
Metastatic Progression ◽  
Surface Receptors ◽  
The Matrix ◽  
Multiple Signaling

Abstract The extracellular matrix is a network of secreted macromolecules that provides a harmonious meshwork for the growth and homeostatic development of organisms. It conveys multiple signaling cascades affecting specific surface receptors that impact cell behavior. During cancer growth, this bioactive meshwork is remodeled and enriched in newly formed blood vessels, which provide nutrients and oxygen to the growing tumor cells. Remodeling of the tumor microenvironment leads to the formation of bioactive fragments that may have a distinct function from their parent molecules, and the balance among these factors directly influence cell viability and metastatic progression. Indeed, the matrix acts as a gatekeeper by regulating the access of cancer cells to nutrients. Here, we will critically evaluate the role of selected matrix constituents in regulating tumor angiogenesis and provide up-to-date information concerning their primary mechanisms of action.

Perancangan aplikasi multi criteria decision making dalam penerimaan beasiswa kepada dosen studi lanjut STMIK Balikpapan menggunakan metode SAW

2018 ◽  
Vol 1 (1) ◽  
pp. 35-42
Author(s):  
Muslimin B ◽  
Sumardi Sumardi
Keyword(s):  
Decision Making ◽  
Learning Process ◽  
Teaching And Learning ◽  
Teaching Assistants ◽  
Multi Criteria Decision Making ◽  
Scholarship Recipients ◽  
The Matrix ◽  
Application Decision ◽  
High Degree ◽  
New Student

 Interests and number of STMIK Balikpapan new student enrollments are increasing every year. The balance of the ratio of lecturers to students is one of the most important components in improving the quality and teaching and learning process of a university. Avoiding shortages in the number of lecturers can be realized by providing scholarship programs to alumni and teaching assistants. This study aims to build a multi criteria decision making application that can assist the Head of HRD in the process of receiving scholarships to advanced and effective study lecturers. The multi criteria decision making application developed in this study uses the SAW method. The implementation of the SAW method includes the process of evaluating the weighting of criteria, evaluating alternative weights, the matrix process, the results of decision making preferences, resulting in the weighting and ranking of each alternative candidate for the scholarship recipient. The results of the evaluation of multi-criteria application decision making in the study are expected to produce modeling with a high degree of accuracy. The results of the analysis carried out can provide alternative recommendations for prospective scholarship recipients to advanced study lecturers in STMIK Balikpapan.

scholarly journals A Novel Composite with Structural Health Monitoring Functionality via 2D and 3D Impedance Mapping Topography

2021 ◽  
Vol 11 (4) ◽  
pp. 1647
Author(s):  
Georgios Foteinidis ◽  
Alkiviadis S. Paipetis
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Carbon Fabric ◽  
Structural Health ◽  
The Matrix ◽  
Junction Points ◽  
Sinusoidal Electric Field ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We report the transformation of a conventional composite material into a multifunctional structure able to provide information about its structural integrity. A purposely positioned grid of carbon fabric strips located within a glass fibre laminate in alternating 0/90 configuration combined with a ternary nanomodified epoxy matrix imparted structural health monitoring (SHM) topographic capabilities to the composite using the impedance spectroscopy (IS) technique. The matrix was reinforced with homogenously dispersed multi-walled carbon nanotubes (MWCNTs) and carbon black (CB). A sinusoidal electric field was applied locally over a frequency range from 1 Hz to 100 kHz between the junction points of the grid of carbon fabric strips. The proposed design enabled topographic damage assessment after a high-velocity impact via the local monitoring of the impedance. The data obtained from the IS measurements were depicted by magnitude and phase delay Bode plots and Nyquist plots. The impedance values were used to create a 2D and a multi-layer (3D) contour topographical image of the damaged area, which revealed crucial information about the structural integrity of the composite.

scholarly journals The Interactions between Polyphenols and Microorganisms, Especially Gut Microbiota

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 188
Author(s):  
Małgorzata Makarewicz ◽  
Iwona Drożdż ◽  
Tomasz Tarko ◽  
Aleksandra Duda-Chodak
Keyword(s):  
Intestinal Bacteria ◽  
Research Data ◽  
Bioactive Metabolites ◽  
Human Organism ◽  
Comprehensive Knowledge ◽  
Bidirectional Relationship ◽  
The Matrix ◽  
Intestinal Pathogens ◽  
The Impact

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols’ impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole “microbiota” and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).

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