scholarly journals Ultra-Porous Nanocellulose Foams: A Facile and Scalable Fabrication Approach

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1142 ◽  
Author(s):  
Carlo Antonini ◽  
Tingting Wu ◽  
Tanja Zimmermann ◽  
Abderrahmane Kherbeche ◽  
Marie-Jean Thoraval ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Weight Ratio ◽  
High Strength ◽  
Mechanical Tests ◽  
Immiscible Liquid ◽  
Absorption Capacity ◽  
Fabrication Process ◽  
High Porosity ◽  
Oil Absorption ◽  
Environmental Pressures

Cellulose nanofibril foams are cellulose-based porous materials with outstanding mechanical properties, resulting from the high strength-to-weight ratio of nanofibrils. Here we report the development of an optimized fabrication process for highly porous cellulose foams, based on a well-controlled freeze-thawing-drying (FTD) process at ambient pressure. This process enables the fabrication of foams with ultra-high porosity, up to 99.4%, density of 10 mg/cm3, and liquid (such as oil) absorption capacity of 100 L/kg. The proposed approach is based on the ice-templating of nanocellulose suspension in water, followed by thawing in ethanol and drying at environmental pressures. As such, the proposed fabrication route overcomes one of the major bottle-necks of the classical freeze-drying approach, by eliminating the energy-demanding vacuum drying step required to avoid wet foam collapse upon drying. As a result, the process is simple, environmentally friendly, and easily scalable. Details of the foam development fabrication process and functionalization are thoroughly discussed, highlighting the main parameters affecting the process, e.g., the concentration of nanocellulose and additives used to control the ice nucleation. The foams are also characterized by mechanical tests and oil absorption measurements, which are used to assess the foam absorption capability as well as the foam porosity. Compound water-in-oil drop impact experiments are used to demonstrate the potential of immiscible liquid separation using cellulose foams.

scholarly journals Implementation of the ultrasonic through-transmission technique for the elastic characterization of fiber-reinforced laminated composite

DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 153-161
Author(s):  
Carlos A. Meza ◽  
Ediguer E. Franco ◽  
Joao L. Ealo
Keyword(s):  
Laminated Composites ◽  
Weight Ratio ◽  
Laminated Composite ◽  
High Strength ◽  
Mechanical Tests ◽  
Fiber Reinforced ◽  
Transmission Technique ◽  
Laminated Materials

Laminated composites are widely used in applications when a high strength-to-weight ratio is required. Aeronautic, naval and automotive industries use these materials to reduce the weight of the vehicles and, consequently, fuel consumption. However, the fiber-reinforced laminated materials are anisotropic and the elastic properties can vary widely due to non-standardized manufacturing processes. The elastic characterization using mechanical tests is not easy, destructive and, in most cases, not all the elastic constants can be obtained. Therefore, alternative techniques are required to assure the quality of the mechanical parts and the evaluation of new materials. In this work, the implementation of the ultrasonic through-transmission technique and the characterization of some engineering materials is reported. Isotropic materials and laminated composites of carbon fiber and glass fiber in a polymer matrix were characterized by ultrasound and mechanical tests. An improved methodology for the transit time delay calculation is reported.

scholarly journals Mechanical assessment of polyurethane impregnated fibreglass bandages for splinting

1987 ◽  
Vol 11 (3) ◽  
pp. 128-134 ◽  
Author(s):  
R. Wytch ◽  
C. B. Mitchell ◽  
D. Wardlaw ◽  
W. M. Ledingham ◽  
I. K. Ritchie
Keyword(s):  
Weight Bearing ◽  
Setting Time ◽  
Weight Ratio ◽  
High Strength ◽  
Mechanical Tests ◽  
Wear Properties ◽  
Orthopaedic Practice ◽  
Current Range ◽  
Plaster Of Paris ◽  
Rapid Setting

The introduction of polyurethane (PU) resin impregnated fibreglass bandages is likely to have a significant effect on modern orthopaedic practice. The manufacturers of these products claim many improved properties compared to plaster of Paris bandages, such as, high strength to weight ratio, rapid setting time and high radiolucency. This paper reports on a series of mechanical tests designed to assess the strength, flexibility, working time and wear properties of the current range of fibreglass bandages and to compare them with plaster of Paris bandages. The results have clearly demonstrated that the fibreglass bandages are mechanically superior and offer numerous advantages over plaster of Paris for use as the definitive casting material for both weight-bearing and non-weight-bearing casts.

scholarly journals Analysing the mechanical behavior of A6061/SiC/B4C/Flyash composite fabricated through stir casting

2018 ◽  
Vol 7 (2.8) ◽  
pp. 424
Author(s):  
N Subramani ◽  
R Krishnan
Keyword(s):  
Mechanical Behavior ◽  
Experimental Studies ◽  
Weight Ratio ◽  
High Strength ◽  
Stir Casting ◽  
Mechanical Tests ◽  
Nano Composite ◽  
Reinforcement Distribution ◽  
Particulate Reinforced ◽  
Carbide Particles

Alloys of Aluminium are prominently used in automobiles, aerospace and ship building industries because of their high strength to weight ratio. The aim of this work is to manufacture the particulate reinforced metal matrix composite (PRMMC) materials by using Aluminium 6061 and reinforcing Boron Carbide, particles of silicon and fly ash. The study helps to fabricate an optimized composite material through the best methodology which is identified at the end of the experimental studies which is going to be carried out. This study helps the current researches carried on the nano-composite materials and PRMMC. In this paper, the Aluminium 6061 and its reinforcements are discussed and it gives a methodology to select the optimized method. The specimens fabricated by stir casting are analyzed and categorized according to their mechanical behavior by conducting mechanical tests. The Micro-structure of the specimen is examined by scanning electron microscopy (SEM) and spectrum analysis is done to the reinforcement distribution percentage.

Preparation and Characterization of Hydrophobic Ceramic Foam

2016 ◽  
Vol 840 ◽  
pp. 77-81
Author(s):  
Nur Syazana Suparman ◽  
Khadijah Ahmad Alwi ◽  
Mohd Al Amin Muhamad Nor
Keyword(s):  
Hydrophobic Effect ◽  
Absorption Capacity ◽  
Solid Content ◽  
Ceramic Foam ◽  
High Porosity ◽  
Oil Absorption ◽  
Foam Ceramic ◽  
Replication Method

Ceramic foam are a class of high porosity materials that are used for various applications. In this study, foam ceramic porcelain powder was produced by using polymeric sponge replication method at different solid content ranging from 30 to 50 wt. %. Properties of ceramic foam was characterized for porosity and density. Ceramic foam then grafted with methyltriethoxysilane (MTMS) at different concentration ranging from 0 to 9.0% v/v to determine hydrophobic effect and oil absorption capacity. From the results, it was found that the density of ceramic foam increased while porosity was decreased with increasing solid contents. It is clearly seen that, MTMS grafting contribute to hydrophobic effect of ceramic foam which enable repelling of water. The amount of oil absorbed by ceramic was found increased by increasing concentration of MTMS for all solid contents. As conclusion, MTMS give significant effects on hyrdophobic ceramic foam and produce good absorption capacity. The lower solid content produced better oil absorption compared to higher solid content due to presence of higher porosity.

Experimental investigation on the mechanical properties of aluminium sandwiched sisal/kenaf/aloevera/jute/flax natural fibre-reinforced epoxy LY556/GY250 composites

2020 ◽  
pp. 096739112097350
Author(s):  
Jeswin Arputhabalan ◽  
L Karunamoorthy ◽  
K Palanikumar
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Fibre Composite ◽  
Matrix Material ◽  
Aloe Vera ◽  
Weight Ratio ◽  
High Strength ◽  
Natural Fibre ◽  
Mechanical Tests ◽  
Natural Fibres

In engineering, composites have indicated a more profound influence in the recent development of materials with high strength to weight ratio. The purpose of this work is to identify the different and specific properties which a composite possesses when various reinforcement fibres are used in different epoxy matrix material. Composite materials have a major role to play with meeting that requirement. Many natural fibre composite materials possess good mechanical properties but still lack in satisfying applications requirements and alternate for which is seen as sandwich natural fibre composites. In this investigation, an effort has been made to study the mechanical properties exhibited by sandwich epoxy composite reinforced with various commonly used natural fibres, namely Aloevera, Kenaf, Sisal, Jute and Flax. The polymer resin used as matrix is also varied using Epoxy LY556 and Epoxy GY250. The originality of this work is in the use of Epoxy GY250 to fabricate sandwich composites with five commonly available natural fibres and compare its performance to the more widely used Epoxy LY556. It has been determined through various mechanical tests, which particular epoxy resin bonds better with the natural fibres namely, jute, sisal, aloe vera, kenaf and flax thereby providing better tensile, impact and flexural properties. The investigation is hoped to provide an insight into how the environmentally friendly natural fibres interact with the varying matrix resins and how this interaction affects the mechanical properties of said composites.

scholarly journals Mechanical behavior of sandwich structure composites for helicopters

2020 ◽  
Vol 12 (4) ◽  
pp. 155-162
Author(s):  
George PELIN ◽  
Cristina-Elisabeta PELIN ◽  
Adriana STEFAN ◽  
Alexandra PETRE ◽  
Alina DRAGOMIRESCU
Keyword(s):  
Mechanical Behavior ◽  
Composite Structure ◽  
Weight Ratio ◽  
High Strength ◽  
Mechanical Tests ◽  
Impact Behavior ◽  
Sandwich Composite ◽  
Maximum Efficiency ◽  
Commercial Aircraft ◽  
Sandwich Composite Structure

The visible part of the floors of a commercial aircraft has long been a standard issue for virtually every commercial aircraft, mainly due to the weight of the materials from which they were made. Floor parts must provide mechanical strength and dimensional stability, while keeping the weight of the aircraft as low as possible for maximum efficiency. The design of the 787 Dreamliner and the Airbus A380 aircraft brought new opportunities in the use of the sandwich composite structure, mainly due to their light weight and high strength-to-weight ratio. Thus, this paper investigates the mechanical behavior of sandwich composite panels composed of two sides of carbon fiber laminate and Nomex honeycomb core obtained in the autoclave and developed under the RoRCraft CompAct grant. The technical approaches of this work are mainly focused on the compression behavior and especially on the compression after impact behavior of the hybrid sandwich composite structure, for defining and obtaining an optimal structure for the floors. These mechanical tests are decisive for such materials and have been performed in accordance with international ASTM standards.

scholarly journals Investigations into Manufacturing Composite Profiles Having Local Magnesium-Foam Reinforcements

2010 ◽  
Vol 137 ◽  
pp. 129-160 ◽  
Author(s):  
Tillmann Plorin ◽  
Dirk Bormann ◽  
Torsten Heidenblut ◽  
Friedrich Wilhelm Bach
Keyword(s):  
High Strength ◽  
Mechanical Tests ◽  
Absorption Capacity ◽  
Roll Forming ◽  
Metallic Foams ◽  
Forming Process ◽  
Research Results ◽  
Foaming Process ◽  
Local Material ◽  
Local Material Properties

Owing to their mechanical properties, metallic foams possess the outstanding ability to considerably improve a structure's stiffness and energy absorption capacity with low increases in weight. In the research results from the sub project A4 "Foam filled, rolled, closed profiles” of the CRC 675 "Creation of high strength metallic structures and joints by setting up scaled local material properties" introduced here, both the manufacture as well as the reinforcement of magnesium foams, which are produced by means of powder metallurgy, are described. The potential for increasing their strengths using reinforcements are demonstrated and the results of mechanical tests are presented. In addition to this, research results are presented which have contributed to achieving the main objectives of developing a combined technology for producing profiles which are locally reinforced using magnesium foam. The developed technology is characterised by integrating the foaming process into the roll forming process.

scholarly journals Fabrication and Properties of Hybrid Coffee-Cellulose Aerogels from Spent Coffee Grounds

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1942 ◽  
Author(s):  
Xiwen Zhang ◽  
Li Ping Kwek ◽  
Duyen K. Le ◽  
Men Shu Tan ◽  
Hai Minh Duong
Keyword(s):  
Absorption Capacity ◽  
Cotton Fibers ◽  
High Porosity ◽  
Oil Absorption ◽  
Spent Coffee Grounds ◽  
Water Contact ◽  
Coffee Grounds ◽  
Coffee Ground ◽  
Average Water ◽  
Hybrid Aerogels

A fully biodegradable hybrid coffee-cotton aerogel has been successfully developed from spent coffee grounds, 100% cotton fiber and polyvinyl alcohol (PVA) flakes via environmental friendly processes. The cotton fibers in coffee aerogel help to maintain the structure and improve the overall properties of the new hybrid coffee-cotton aerogel. The results show that increasing the concentration of fibers, while keeping the concentration of spent coffee grounds constant, the sinking of coffee ground particles in solution and shrinking effect on the aerogels are minimized and the overall mechanical and oil absorption properties are improved. The developed hybrid aerogels possess high porosity of 92–95% and super-hydrophobicity with an average water contact angle of 139°. Oil absorption capacity achieves 16 g/g with 0.50 wt.% of cotton fibers inside the coffee aerogel. Their thermal conductivity is in the range of 0.037–0.045 W/mK and compressive Young’s modulus achieves highest at 15.6 kPa. The properties of the hybrid aerogel indicate it as a potential material in several applications such as thermal insulation, oil absorption and filtration.

Fabrication technique using a core and cavity mold of a hybrid composite ballistic helmet

2021 ◽  
Vol 21 (3) ◽  
pp. 623-629
Author(s):  
M.S.A.M. Alim ◽  
F. Mustapha ◽  
M.N. Abdullah ◽  
M.T.H. Sultan ◽  
M.K.H. Muda
Keyword(s):  
Room Temperature ◽  
Impact Resistance ◽  
Weight Ratio ◽  
High Strength ◽  
Fabrication Process ◽  
Mold Design ◽  
Molding Process ◽  
Thermoset Resin ◽  
Shaping Process ◽  
Curing Methods

Material used for helmet technology has transformed moderately little since the introduction of aramids, which ballistic helmets still uses woven aramids with a thermoset resin system. Most widely used strengthening material for ballistic helmet is Kevlar fibers which comprise outstanding impact resistance and high strength to weight ratio. For Kevlar reinforcement and resin shaping process, composite materials uses molding process in the fabrication methods. The most vital fabrication method is the hand lay-up process. Hand lay-up process normally consists of laying a dry fabric layer by hand onto a mold to shape into desirable design and shape. After the lay-up process is done, resin is then applied to the dry plies. There are several accessible curing methods and the most commonly used method is to let the product to cure at room temperature. This paper presents the fabrication process of ballistic helmet using a hand lay-up fabrication process with a core and cavity mold. This paper also describes the helmet mold design, materials and processing methods.

Fabrication and Comparison of Mechanical Properties of Jute and Glass Fibre Reinforced Composites

2014 ◽  
Vol 592-594 ◽  
pp. 344-348
Author(s):  
Ram Rohit ◽  
Linford Pinto ◽  
K.Mallikharjuna Babu ◽  
Martin Jebraj ◽  
Harsha R. Gudi
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Fibre Composite ◽  
Damping Ratio ◽  
Weight Ratio ◽  
High Strength ◽  
Natural Fibre ◽  
Mechanical Tests ◽  
Reinforced Composites ◽  
Artificial Fibre

The properties of fiber reinforced composites (FRP) like high strength to weight ratio, high stiffness to weight ratio, flexibility in design, ease of fabrication with economical savings as compared to metal alloys, make it an excellent choice for various range of products from building materials, sporting equipment, appliances, automotive parts, boats, canoe hulls to bodies for recreational vehicles. In this study the properties of natural fibre composite are compared with composite made of artificial fibres. The natural fibre chosen is jute fibre and the artificial fibre chosen is glass fiber. Polyester resin was the matrix used because of compatibility, cost effectiveness and easy availability. The composites were fabricated by Hand Layup technique and the number of layers of composite laminate was varied as three, four and five. The specimens were subjected to mechanical tests and Young’s Modulus, Ultimate Strength were evaluated. Modal analysis was carried out to determine the damping characteristics through damping ratio. A comparison of the two composites in terms of mechanical properties is made and the results are tabulated.

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