Chitin Nanofibers / Epoxy Resin Optically Transparent Nanocomposite Films

2012 ◽  
Vol 602-604 ◽  
pp. 1479-1483 ◽  
Author(s):  
Xu Shao ◽  
Da Gang Li ◽  
Ai Jun Li ◽  
Wen Biao Gu
Keyword(s):  
Epoxy Resin ◽  
Coefficient Of Thermal Expansion ◽  
Optoelectronic Devices ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
The Novel ◽  
Flexible Displays ◽  
Novel Material ◽  
Ph Conditions ◽  
Chitin Nanofibers

Chitin nanofibers were prepared from prawn shell by a simple mechanical treatment after the removal of proteins and minerals. Since the exoskeleton of prawn is made up of a finer structure nano-fibrillation of prawn shell is easy, which allows chitin nanofibers to be prepared under neutral pH conditions. The obtained nanofibers were observed by FE-SEM and found to have a uniform width of approximately 20-40nm and high aspect ratio that more than 1000. Due to the size effect of the chitin nanofibers, the nanocomposite films had high transparency that the chitin nanofibers/epoxy resin nanocomposite transmitted 85.2% of light compared to the light transmittance of pure epoxy resin（91%）and the light transmittance of pure chitin nanofibers sheet (70.1%) at a visible wavelength of 600nm. In the study the coefficient of thermal expansion (CTE) from 20 to 160°C of the epoxy resin sheet was measured to be 170 ppm/K. By adding 40 wt% of chitin nanofibers, the CTE of the epoxy resin dropped to 22 ppm/K, approximately 1/8th of its original value. The novel material is a candidate for transparent substrates in the manufacturing optoelectronic devices such as flexible displays and solar cells.

Theoretical Ecology

2007 ◽  
Keyword(s):  
Spatial Dynamics ◽  
Theory And Practice ◽  
The Novel ◽  
Basic Principles ◽  
Theoretical Ecology ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Interacting Populations ◽  
Novel Material ◽  
Ecological Science

Robert May's seminal book has played a central role in the development of ecological science. Originally published in 1976, this influential text has overseen the transition of ecology from an observational and descriptive subject to one with a solid conceptual core. Indeed, it is a testament to its influence that a great deal of the novel material presented in the earlier editions has now been incorporated into standard undergraduate textbooks. It is now a quarter of a century since the publication of the second edition, and a thorough revision is timely. Theoretical Ecology provides a succinct, up-to-date overview of the field set in the context of applications, thereby bridging the traditional division of theory and practice. It describes the recent advances in our understanding of how interacting populations of plants and animals change over time and space, in response to natural or human-created disturbance. In an integrated way, initial chapters give an account of the basic principles governing the structure, function, and temporal and spatial dynamics of populations and communities of plants and animals. Later chapters outline applications of these ideas to practical issues including fisheries, infectious diseases, tomorrow's food supplies, climate change, and conservation biology. Throughout the book, emphasis is placed on questions which as yet remain unanswered. The editors have invited the top scientists in the field to collaborate with the next generation of theoretical ecologists. The result is an accessible, advanced textbook suitable for senior undergraduate and graduate level students as well as researchers in the fields of ecology, mathematical biology, environmental and resources management. It will also be of interest to the general reader seeking a better understanding of a range of global environmental problems.

scholarly journals Synthesis of nanocomposite films based on conjugated oligomer-2D layered MoS2 as potential candidate for optoelectronic devices

2021 ◽  
Vol 33 (3) ◽  
pp. 101389
Author(s):  
F. Barakat ◽  
Mohamad S. AlSalhi ◽  
Saradh Prasad ◽  
S. Alterary ◽  
S. Faraji ◽  
...  
Keyword(s):  
Optoelectronic Devices ◽  
Nanocomposite Films ◽  
Potential Candidate ◽  
Layered Mos2

Modeling of functionally graded materials to estimate effective thermo-mechanical properties

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Royal Madan ◽  
Shubhankar Bhowmick
Keyword(s):  
Experimental Data ◽  
Functionally Graded Materials ◽  
Coefficient Of Thermal Expansion ◽  
Functionally Graded ◽  
Graded Materials ◽  
Content Type ◽  
Wide Range ◽  
Metal Metal ◽  
Novel Material ◽  
First Time

Purpose Functionally graded materials are a special class of composites in which material are graded either continuously or layered wise depending upon its applications. With such variations of materials, the properties of structure vary either lengthwise or thickness wise. This paper aims to investigate models for effective estimation of material properties, as it is necessary for industries to identify the properties of composites or functionally graded materials (FGM’s) before manufacturing and also to develop novel material combinations. Design/methodology/approach Available models were compared for different material combinations and tested with experimental data for properties such as Young’s modulus, density, coefficient of thermal expansion (CTE) and thermal conductivity. Combinations of metal–ceramic and metal–metal were selected such that their ratios cover a wide range of materials. Findings This study reveals different models will be required depending on the material used and properties to be identified. Practical implications The results of the present work will help researchers in the effective modeling of composites or FGM’s for any analysis. Originality/value This paper presents a comparison and review of various analytical methods with experimental data graphically to find out the best suitable method. For the first time, the Halpin-Tsai model was extended in the analysis of the CTE which shows good approximations.

scholarly journals Biodegradation of Microplastic Derived from Poly(ethylene terephthalate) with Bacterial Whole-Cell Biocatalysts

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1326 ◽  
Author(s):  
Jixian Gong ◽  
Tongtong Kong ◽  
Yuqiang Li ◽  
Qiujin Li ◽  
Zheng Li ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
Feedback Inhibition ◽  
Culture Solution ◽  
The Novel ◽  
Whole Cell ◽  
Novel Approach ◽  
Poly Ethylene Terephthalate ◽  
Ph Conditions ◽  
Poly Ethylene ◽  
Neutral Conditions

At present, the pollution of microplastic directly threatens ecology, food safety and even human health. Polyethylene terephthalate (PET) is one of the most common of microplastics. In this study, the micro-size PET particles were employed as analog of microplastic. The engineered strain, which can growth with PET as sole carbon source, was used as biocatalyst for biodegradation of PET particles. A combinatorial processing based on whole-cell biocatalysts was constructed for biodegradation of PET. Compared with enzymes, the products can be used by strain growth and do not accumulated in culture solution. Thus, feedback inhibition of products can be avoided. When PET was treated with the alkaline strain under high pH conditions, the product concentration was higher and the size of PET particles decreased dramatically than that of the biocatalyst under neutral conditions. This shows that the method of combined processing of alkali and organisms is more efficient for biodegradation of PET. The novel approach of combinatorial processing of PET based on whole-cell biocatalysis provides an attractive avenue for the biodegradation of micplastics.

Spectroscopic and Electrical Properties of Ag2S/PVA Nanocomposite Films for Visible-Light Optoelectronic Devices

2020 ◽  
Vol 30 (10) ◽  
pp. 3878-3885 ◽  
Author(s):  
Sami S. Alharthi ◽  
Ahmed Alzahrani ◽  
M. A. N. Razvi ◽  
Ali Badawi ◽  
Mohammed G. Althobaiti
Keyword(s):  
Electrical Properties ◽  
Visible Light ◽  
Optoelectronic Devices ◽  
Nanocomposite Films

scholarly journals Improving the Performance of Feather Keratin/Polyvinyl Alcohol/Tris(hydroxymethyl)Aminomethane Nanocomposite Films by Incorporating Graphene Oxide or Graphene

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 327 ◽  
Author(s):  
Shufang Wu ◽  
Xunjun Chen ◽  
Tiehu Li ◽  
Yingde Cui ◽  
Minghao Yi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
Water Vapor Permeability ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
Vapor Permeability ◽  
Blend Films ◽  
Feather Keratin ◽  
Degradation Temperature ◽  
Bionanocomposite Films

In this study, feather keratin/polyvinyl alcohol/tris(hydroxymethyl)aminomethane (FK/PVA/Tris) bionanocomposite films containing graphene oxide (GO) (0.5, 1, 2, and 3 wt%) or graphene (0.5, 1, 2, and 3 wt%) were prepared using a solvent casting method. The scanning electron microscopy results indicated that the dispersion of GO throughout the film matrix was better than that of graphene. The successful formation of new hydrogen bonds between the film matrix and GO was confirmed through the use of Fourier-transform infrared spectroscopy. The tensile strength, elastic modulus, and initial degradation temperature of the films increased, whereas the total soluble mass, water vapor permeability, oxygen permeability, and light transmittance decreased following GO or graphene incorporation. In summary, nanoblending is an effective method to promote the application of FK/PVA/Tris-based blend films in the packaging field.

scholarly journals Preparation and characterization of novel naphthyl epoxy resin containing 4-fluorobenzoyl side chains for low-k dielectrics application

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 53970-53976 ◽  
Author(s):  
Tianyi Na ◽  
Hao Jiang ◽  
Liang Zhao ◽  
Chengji Zhao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Side Chains ◽  
The Novel ◽  
Lower Dielectric Constant ◽  
Low K

The novel naphthyl epoxy resin was synthesized and cured with MeHHPA. It showed significantly lower dielectric constant and dielectric loss than other commercial epoxy resins due to the introduction of fluorine on the side chains.

scholarly journals Study on the Properties of Transparent Bamboo Prepared by Epoxy Resin Impregnation

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 863 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang ◽  
Jing Wang ◽  
Xuehua Wang
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Visible Light ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Light Transmittance ◽  
Advantages And Disadvantages ◽  
Heat Treated ◽  
Before And After ◽  
Different Parts

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.

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