scholarly journals Cellulose Nanocomposites of Cellulose Nanofibers and Molecular Coils

2021 ◽  
Vol 5 (8) ◽  
pp. 200
Author(s):  
Doug Henderson ◽  
Xin Zhang ◽  
Yimin Mao ◽  
Liangbing Hu ◽  
Robert M. Briber ◽  
...  
Keyword(s):  
Small Angle Neutron Scattering ◽  
Fracture Strain ◽  
Composition Range ◽  
Cellulose Nanofibers ◽  
Tensile Tests ◽  
Uptake Capacity ◽  
Amorphous Cellulose ◽  
Cellulose Composites ◽  
Water Uptake Capacity ◽  
Cellulose Nanocomposites

All-cellulose nanocomposites have been produced from cellulose nanofiber (CNF) suspensions and molecular coil solutions. Morphology and small-angle neutron scattering studies show the exfoliation and dispersion of CNFs in aqueous suspensions. Cellulose solutions in mixtures of ionic liquid and organic solvents were homogeneously mixed with CNF suspensions and subsequently dried to yield cellulose composites comprising CNF and amorphous cellulose over the entire composition range. Tensile tests show that stiffness and strength quantities of cellulose nanocomposites are the highest value at ca. 20% amorphous cellulose, while their fracture strain and toughness are the lowest. The inclusion of amorphous cellulose in cellulose nanocomposites alters their water uptake capacity, as measured in the ratio of the absorbed water to the cellulose mass, reducing from 37 for the neat CNF to less than 1 for a composite containing 35% or more amorphous cellulose. This study offers new insights into the design and production of all-cellulose nanocomposites.

scholarly journals Strengthening of Porcine Plasma Protein Superabsorbent Materials through a Solubilization-Freeze-Drying Process

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 772
Author(s):  
Estefanía Álvarez-Castillo ◽  
Carlos Bengoechea ◽  
Antonio Guerrero
Keyword(s):  
Water Uptake ◽  
Plasma Protein ◽  
Freeze Drying ◽  
Meat Industry ◽  
Drying Process ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
Protein Flour ◽  
Hydrophilic Materials ◽  
By Products

The replacement of common acrylic derivatives by biodegradable materials in the formulation of superabsorbent materials would lessen the associated environmental impact. Moreover, the use of by-products or biowastes from the food industry that are usually discarded would promote a desired circular economy. The present study deals with the development of superabsorbent materials based on a by-product from the meat industry, namely plasma protein, focusing on the effects of a freeze-drying stage before blending with glycerol and eventual injection molding. More specifically, this freeze-drying stage is carried out either directly on the protein flour or after its solubilization in deionized water (10% w/w). Superabsorbent materials obtained after this solubilization-freeze-drying process display higher Young’s modulus and tensile strength values, without affecting their water uptake capacity. As greater water uptake is commonly related to poorer mechanical properties, the proposed solubilization-freeze-drying process is a useful strategy for producing strengthened hydrophilic materials.

scholarly journals Incorporation of ZnO Nanoparticles into Soy Protein-Based Bioplastics to Improve Their Functional Properties

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 486
Author(s):  
Mercedes Jiménez-Rosado ◽  
Víctor Perez-Puyana ◽  
Pablo Sánchez-Cid ◽  
Antonio Guerrero ◽  
Alberto Romero
Keyword(s):  
Controlled Release ◽  
Environmental Impact ◽  
Soy Protein ◽  
Zno Nanoparticles ◽  
Injection Moulding ◽  
Mould Temperature ◽  
Uptake Capacity ◽  
Nanoparticle Distribution ◽  
Water Uptake Capacity ◽  
Key Factor

The union of nanoscience (nanofertilization) with controlled release bioplastic systems could be a key factor for the improvement of fertilization in horticulture, avoiding excessive contamination and reducing the price of the products found in the current market. In this context, the objective of this work was to incorporate ZnO nanoparticles in soy protein-based bioplastic processed using injection moulding. Thus, the concentration of ZnO nanoparticles (0 wt%, 1.0 wt%, 2.0 wt%, 4.5 wt%) and mould temperature (70 °C, 90 °C and 110 °C) were evaluated through a mechanical (flexural and tensile properties), morphological (microstructure and nanoparticle distribution) and functional (water uptake capacity, micronutrient release and biodegradability) characterization. The results indicate that these parameters play an important role in the final characteristics of the bioplastics, being able to modify them. Ultimately, this study increases the versatility and functionality of the use of bioplastics and nanofertilization in horticulture, helping to prevent the greatest environmental impact caused.

Synthesis and characterization of poly(glycerol sebacate)-based elastomeric copolyesters for tissue engineering applications

2016 ◽  
Vol 7 (14) ◽  
pp. 2553-2564 ◽  
Author(s):  
Yating Jia ◽  
Weizhong Wang ◽  
Xiaojun Zhou ◽  
Wei Nie ◽  
Liang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Water Uptake ◽  
Synthesis And Characterization ◽  
Uptake Capacity ◽  
Engineering Applications ◽  
Water Uptake Capacity

A poly(glycerol sebacate)-based elastomeric copolyesters with improved mechanical properties and higher water uptake capacity.

Development of green nanocomposites reinforced by cellulose nanofibers extracted from paper sludge

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540025 ◽  
Author(s):  
Hitoshi Takagi ◽  
Antonio N. Nakagaito ◽  
Kazuya Kusaka ◽  
Yuya Muneta
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Mechanical Treatment ◽  
Raw Materials ◽  
Cellulose Nanofibers ◽  
Tensile Tests ◽  
Cellulose Nanofiber ◽  
Paper Sludge ◽  
Reinforcing Effect ◽  
Mechanical And Physical Properties

Cellulose nanofibers have been showing much greater potential to enhance the mechanical and physical properties of polymer-based composite materials. The purpose of this study is to extract the cellulose nanofibers from waste bio-resources; such as waste newspaper and paper sludge. The cellulosic raw materials were treated chemically and physically in order to extract individualized cellulose nanofiber. The combination of acid hydrolysis and following mechanical treatment resulted in the extraction of cellulose nanofibers having diameter of about 40 nm. In order to examine the reinforcing effect of the extracted cellulose nanofibers, fully biodegradable green nanocomposites were fabricated by composing polyvinyl alcohol (PVA) resin with the extracted cellulose nanofibers, and then the tensile tests were conducted. The results showed that the enhancement in mechanical properties was successfully obtained in the cellulose nanofiber/PVA green nanocomposites.

Preparation and Property of Waterborne Polyurethane/Cellulose Nanofiber Nanocomposite Films

2020 ◽  
Vol 993 ◽  
pp. 631-637
Author(s):  
Yu Zhe Lin ◽  
Jia Min Zeng ◽  
Jing Hong Ma ◽  
Jing Hua Gong
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibers ◽  
Waterborne Polyurethane ◽  
Tensile Tests ◽  
Environmental Safety ◽  
Nanocomposite Films ◽  
Solution Blending ◽  
Low Weight ◽  
New Type ◽  
Dispersing Medium

Waterborne polyurethane (WPU) is a new type of polyurethane system, which using water instead of organic solvent as dispersing medium. Because of its non-toxicity and environmental safety, WPU is considered as the development direction of coatings and adhesives. However, the mechanical properties of WPU are worse than that of solvent-based polyurethane, therefore, the modification of WPU has received increasingly attention. Meanwhile numerous evidences demonstrate the excellent properties of cellulose nanofibers (CNFs) such as high aspect ratio, low weight and outstanding mechanical strength. Therefore, there is a high expectation for CNFs to be introduced into WPU as reinforcing filler. In this work, a series of CNFs/WPU nanocomposite films were prepared by solution blending. The structure, morphology, thermal behavior and mechanical properties were investigated. SEM results showed that CNFs were evenly dispersed in the WPU matrix. Tensile tests indicated that the modulus and tensile strength of CNFs/WPU nanocomposite films were improved compared with the neat film. While the break elongation of the nanocomposite films decreased with the increase of CNFs content. The synergistic interaction between CNFs and WPU matrix plays an important role in the enhancement of mechanical properties.

scholarly journals Electroactive Hydrogels Made with Polyvinyl Alcohol/Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1615 ◽  
Author(s):  
Tippabattini Jayaramudu ◽  
Hyun-U Ko ◽  
Hyun Kim ◽  
Jung Kim ◽  
Ruth Muthoka ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Active Drug ◽  
X Ray Diffraction ◽  
Uptake Capacity ◽  
X Ray ◽  
Freeze Thaw ◽  
Actuation Mechanism ◽  
Water Uptake Capacity ◽  
Electrostatic Effect ◽  
Scanning Electron

This paper reports a nontoxic, soft and electroactive hydrogel made with polyvinyl alcohol (PVA) and cellulose nanocrystal (CNC). The CNC incorporating PVA-CNC hydrogels were prepared using a freeze–thaw technique with different CNC concentrations. Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy results proved the good miscibility of CNCs with PVA. The optical transparency, water uptake capacity and mechanical properties of the prepared hydrogels were investigated in this study. The CNC incorporating PVA-CNC hydrogels showed improved displacement output in the presence of an electric field and the displacement increased with an increase in the CNC concentration. The possible actuation mechanism was an electrostatic effect and the displacement improvement of the hydrogel associated with its enhanced dielectric properties and softness. Since the prepared PVA-CNC hydrogel is nontoxic and electroactive, it can be used for biomimetic soft robots, actively reconfigurable lenses and active drug-release applications.

Bentonites -

2021 ◽  
Author(s):  
Wen-An Chiou ◽  
Helmut Coutelle ◽  
Andreas Decher ◽  
Michael Dörschug ◽  
Reiner Dohrmann ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Bentonite Clay ◽  
Drilling Mud ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
High Level Nuclear Waste ◽  
And Performance ◽  
Swelling Clay Minerals ◽  
High Level ◽  
And Control

<p><b>Bentonites</b> are rocks mostly consisting of swelling clay minerals. They were first described from the Cretaceous Benton Shale near Rock River, Wyoming, USA. </p> <p> Because of their useful properties (e.g. highly adsorbent, cation exchanging, swelling), bentonites have many uses, in industry (among them as drilling mud, purification agent, binder, adsorbent, paper production), culture (for e.g. pottery) and medicine/cosmetics/cat litter, civil engineering, and in the future even in the disposal of high-level nuclear waste. </p> <p> Particular chemical characteristics of bentonite clay minerals are rather variable but critically determine their suitability for a particular application. </p> <p> The 15 specialist authors discuss bentonite terminology, classification and genesis and use in eight chapters. Individual chapters deal with the methods bentonites are analysed with, their properties and performance in terms of parameters such as cation exchange capactiy, rheology, coagulation concentraion, water uptake capacity, free swelling, and electrical resistivity (amongst others). </p> <p> A chapter is dedicated to the sources of bentonites, the technology employed to produce them, and how quality control is carried out both in the mine and the laboratory. A further chapter is dedicated to methods of processing the mined material, different activation methods, drying, grinding, and purification. </p> <P> Use cases for bentonites are discussed in a chapter of its own. References, a section on norms and standards, and a list of abbreviations complete the text. </p> <p> The volume addresses students, researchers, and professionals in the mineral industry dealing with bentonite and their clay-mineral constituents, quality assessement and control, and persons that use bentonites in their products. </p>

Sign in / Sign up

Export Citation Format

Share Document