scholarly journals Properties of Biocomposites from Rapeseed Meal, Fruit Pomace and Microcrystalline Cellulose Made by Press Pressing: Mechanical and Physicochemical Characteristics

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 890 ◽  
Author(s):  
Tomasz Żelaziński
Keyword(s):  
Microcrystalline Cellulose ◽  
Colour Change ◽  
Rapeseed Meal ◽  
Physicochemical Characteristics ◽  
Mechanical Tests ◽  
Hydraulic Press ◽  
Electron Microscopic ◽  
Water Contact ◽  
Primary Sample ◽  
Fruit Pomace

This paper presents the results of research on biocomposites made of the mixture of post-extraction rapeseed meal, microcrystalline cellulose and various fruit pomace (chokeberry, blackcurrant, apple and raspberry pomace). The biocomposites were made in the process of mechanical thickening by means of a heated mould (die and stamp) which is located between two heating elements installed on a hydraulic press. The presented research combines mechanical engineering and material engineering issues. The physical and mechanical tests of obtained biocomposites included mechanical strength measurements, thermogravimetric analyses (TGA), colour change tests and scanning electron microscopic (SEM) tests of the internal structure after breaking the sample. In addition, Fourier transform infrared spectroscopy (FTIR) tests were carried out. Generally, the bend tests and Young’s modulus were significantly increased, for example, biocomposites with an addition of chokeberry pomace had the flexural strength higher by approximately 25% in relation to the primary sample. Furthermore, it is interesting to note the increase of water contact angle of these biocomposites by 40% in relation to the primary sample. The research indicates the potential for using fruit pomace for the needs of biocomposite production.

scholarly journals Cellulose Acetate-Based Electrospun Materials with a Variety of Biological Potentials: Antibacterial, Antifungal and Anticancer

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1631
Author(s):  
Mariya Spasova ◽  
Nevena Manolova ◽  
Iliya Rashkov ◽  
Petya Tsekova ◽  
Ani Georgieva ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Mechanical Tests ◽  
Fibrous Materials ◽  
Water Contact ◽  
Antibacterial And Antifungal Activities ◽  
3T3 Fibroblasts ◽  
Angle Measurements ◽  
Zones Of Inhibition ◽  
Model Drug ◽  
Antibacterial And Antifungal

Novel eco-friendly fibrous materials with complex activities from cellulose acetate and cellulose acetate/polyethylene glycol (CA,PEG) containing 5-chloro-8-hydroxyquinoline as a model drug were obtained by electrospinning. Several methods, including scanning electron microscopy, X-ray diffraction analysis, ultraviolet-visible spectroscopy, water contact angle measurements, and mechanical tests, were utilized to characterize the obtained materials. The incorporation of PEG into the fibers facilitated the drug release. The amounts of the released drug from CA/5-Cl8Q and CA,PEG/5-Cl8Q were 78 ± 3.38% and 86 ± 3.02%, respectively (for 175 min). The antibacterial and antifungal activities of the obtained materials were studied. The measured zones of inhibition of CA/5-Cl8Q and CA,PEG/5-Cl8Q mats were 4.0 ± 0.18 and 4.5 ± 0.2 cm against S. aureus and around 4.0 ± 0.15 and 4.1 ± 0.22 cm against E. coli, respectively. The complete inhibition of the C. albicans growth was detected. The cytotoxicity of the obtained mats was tested toward HeLa cancer cells, SH-4 melanoma skin cells, and mouse BALB/c 3T3 fibroblasts as well. The CA/5-Cl8Q and CA,PEG/5-Cl8Q materials exhibited anticancer activity and low normal cell toxicity. Thus, the obtained fibrous materials can be suitable candidates for wound dressing applications and for application in local cancer treatment.

scholarly journals PLA-Based Hybrid and Composite Electrospun Fibrous Scaffolds as Potential Materials for Tissue Engineering

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Magiera ◽  
Jarosław Markowski ◽  
Elzbieta Menaszek ◽  
Jan Pilch ◽  
Stanislaw Blazewicz
Keyword(s):  
Tissue Engineering ◽  
Mechanical Tests ◽  
Hybrid Structures ◽  
Poly Lactic Acid ◽  
Electrospinning Technique ◽  
Water Contact ◽  
Human Osteoblasts ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Normal Human

The aim of the study was to manufacture poly(lactic acid)- (PLA-) based nanofibrous nonwovens that were modified using two types of modifiers, namely, gelatin- (GEL-) based nanofibres and carbon nanotubes (CNT). Hybrid nonwovens consisting of PLA and GEL nanofibres (PLA/GEL), as well as CNT-modified PLA nanofibres with GEL nanofibres (PLA + CNT/GEL), in the form of mats, were manufactured using concurrent-electrospinning technique (co-ES). The ability of such hybrid structures as potential scaffolds for tissue engineering was studied. Both types of hybrid samples and one-component PLA and CNTs-modified PLA mats were investigated using scanning electron microscopy (SEM), water contact angle measurements, and biological and mechanical tests. The morphology, microstructure, and selected properties of the materials were analyzed. Biocompatibility and bioactivity in contact with normal human osteoblasts (NHOst) were studied. The coelectrospun PLA and GEL nanofibres retained their structures in hybrid samples. Both types of hybrid nonwovens were not cytotoxic and showed better osteoinductivity in comparison to scaffolds made from pure PLA. These samples also showed significantly reduced hydrophobicity compared to one-component PLA nonwovens. The CNT-contained PLA nanofibres improved mechanical properties of hybrid samples and such a 3D system appears to be interesting for potential application as a tissue engineering scaffold.

scholarly journals The Rape Pomace and Microcrystalline Cellulose Composites Made by Press Processing

2020 ◽  
Vol 12 (4) ◽  
pp. 1311 ◽  
Author(s):  
Tomasz Żelaziński ◽  
Jacek Słoma ◽  
Jacek Skudlarski ◽  
Adam Ekielski
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microcrystalline Cellulose ◽  
Heating System ◽  
Rapeseed Meal ◽  
Thermomechanical Properties ◽  
Process Temperature ◽  
Stress Tests ◽  
Cellulose Composites ◽  
Scanning Electron

This paper presents the results of research on biocomposites resulting from the combination of post-extraction rapeseed meal (RP) and microcrystalline cellulose (MCC). The products were fabricated using a press machine with a mould heating system. The biocomposites were then subjected to stress tests, their surface wettability was determined and color analyses were conducted. Fourier Transform Infrared Spectroscopy (FTIR), a cross-section observed by scanning electron microscope (SEM) and thermogravimetric analysis (TGA) were used to examine the structure and thermomechanical properties of the material obtained. The research results showed that an increase in the share of MCC to 8% and increasing the process temperature to 140 °C improved the strength parameters of the products obtained, as well as their thermal resistance. It was also found that the wettability of products was affected both by process temperature and addition of cellulose; similar wettability results were obtained for MCC 8% (120 °C) and MCC 2% (140 °C). Photographs taken using a scanning electron microscope revealed that the biocomposite surface was the smoothest in the case of materials fabricated under the highest process temperature and with the highest MCC proportion.

The Effect of Substituting Metakaolin for Sand on the Thermomechanical Behaviour of Reactive Powder Concrete (RPC)

2019 ◽  
Vol 41 ◽  
pp. 115-130
Author(s):  
Nawal Siham Adamou Doumi ◽  
Hadjila Bournine Amrane ◽  
Ali Ahmed Benyahia
Keyword(s):  
Mechanical Strength ◽  
Microscopic Analysis ◽  
Mechanical Tests ◽  
Reactive Powder Concrete ◽  
Compression Tests ◽  
Electron Microscopic ◽  
Major Drawback ◽  
Thermomechanical Behaviour ◽  
Substitution Ratio ◽  
Reactive Powder

The weakening of the behavior of reactive powder concrete (RPC) under high temperature is a major drawback; therefore, it is necessary to find an ingredient that improves their resistance under rising temperatures. The present work involves the use of metakaolin as a substitute for sand in a reactive powder concrete (RPC) in order to assess its effect on the mechanical strength at high temperatures. The test specimens are preheated up to 100°, 300°, 500°, 700° and 900°C, respectively following a well-defined cycle, thereafter subjected to a three-point bending followed by compression tests. Samples of the tested specimens were used for thermal, mineralogical and microstructural analyses using the thermogravimetric and differential thermal analysis (TG / DTA), the X-ray diffraction (XRD) and the scanning electron microscopic Analysis (SEM).The heating tests revealed that all the specimens exploded before reaching 500°C. However, they can withstand 300°C before exploding for different exposure durations depending on the metakaolin substitution ratio. Therefore, the mechanical tests were applied only on unheated specimens and those heated up to 100°C. The results showed that the use of metakaolin improves the mechanical strength of the RPC, both at room temperature (25°C±1°C) and at 100°C. This result is confirmed by the microstructure analysis, which revealed the absence of portlandite. The latter did react with the metakaolin silica to form new calcium silicate hydrates (CSH) enhancing the mechanical strength.

scholarly journals Alumina sludge's Influence on the physicochemical characteristics of CPJ55 cement

2018 ◽  
Vol 149 ◽  
pp. 01058 ◽  
Author(s):  
M. Dahhou ◽  
R. Barbach ◽  
M. El Moussaouiti
Keyword(s):  
Portland Cement ◽  
Xrd Analysis ◽  
Physicochemical Characteristics ◽  
Mechanical Tests ◽  
Partial Replacement ◽  
Free Lime ◽  
Water Plant ◽  
Strength Tests ◽  
Characterization Of Materials

Partial replacement of the Portland cement CPJ55 ingredients by various quantities of alumina sludge (AS), produced during drinking water plant sludge, was used in the preparation of mortar mold with dimensions 40×40×160 mm. The characterization of materials is carried out by X-ray fluorescence (XRF), Xray diffraction (XRD), free lime dosing, and the mechanical tests. Analysis of the chemical composition by XRF shows that the studied alumina sludge is mainly composed of aluminum oxide, silica, which is correlated with the principal mineral phases identified in the XRD analysis results. It is demonstrated that adding 5% of the alumina sludge in Portland cement does not affect the mineralogy of final product. Nevertheless, the compression and flexural strength tests (in 28 days) conducted on mortar sample comprising 5% sludge elucidate that it belongs to cement mortar class of type 32.5 R.

scholarly journals Mechanical and Morphological Properties of Polypropylene/Nanoα-Al2O3Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
F. Mirjalili ◽  
L. Chuah ◽  
E. Salahi
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Mechanical Tests ◽  
Filler Loading ◽  
Morphological Properties ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Flexural Analysis ◽  
Flexural Tests ◽  
Internal Mixer

A nanocomposite containing polypropylene (PP) and nanoα-Al2O3particles was prepared using a Haake internal mixer. Mechanical tests, such as tensile and flexural tests, showed that mechanical properties of the composite were enhanced by addition of nanoα-Al2O3particles and dispersant agent to the polymer. Tensile strength was approximately∼16% higher than pure PP by increasing the nanoα-Al2O3loading from 1 to 4 wt% into the PP matrix. The results of flexural analysis indicated that the maximum values of flexural strength and flexural modulus for nanocomposite without dispersant were 50.5 and 1954 MPa and for nanocomposite with dispersant were 55.88 MPa and 2818 MPa, respectively. However, higher concentration of nanoα-Al2O3loading resulted in reduction of those mechanical properties that could be due to agglomeration of nanoα-Al2O3particles. Transmission and scanning electron microscopic observations of the nanocomposites also showed that fracture surface became rougher by increasing the content of filler loading from 1 to 4% wt.

scholarly journals Surface Modification of Additively Manufactured Nitinol by Wet Chemical Etching

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7683
Author(s):  
Denis Nazarov ◽  
Aida Rudakova ◽  
Evgenii Borisov ◽  
Anatoliy Popovich
Keyword(s):  
Mechanical Properties ◽  
Free Surface ◽  
Surface Energy ◽  
Surface Composition ◽  
Three Dimensional ◽  
Physicochemical Characteristics ◽  
Contact Angles ◽  
Free Surface Energy ◽  
Flat Plates ◽  
Water Contact

Three-dimensional printed nitinol (NiTi) alloys have broad prospects for application in medicine due to their unique mechanical properties (shape memory effect and superplasticity) and the possibilities of additive technologies. However, in addition to mechanical properties, specific physicochemical characteristics of the surface are necessary for successful medical applications. In this work, a comparative study of additively manufactured (AM) NiTi samples etched in H2SO4/H2O2, HCl/H2SO4, and NH4OH/H2O2 mixtures was performed. The morphology, topography, wettability, free surface energy, and chemical composition of the surface were studied in detail. It was found that etching in H2SO4/H2O2 practically does not change the surface morphology, while HCl/H2SO4 treatment leads to the formation of a developed morphology and topography. In addition, exposure of nitinol to H2SO4/H2O2 and HCl/H2SO4 contaminated its surface with sulfur and made the surface wettability unstable in air. Etching in NH4OH/H2O2 results in surface cracking and formation of flat plates (10–20 microns) due to the dissolution of titanium, but clearly increases the hydrophilicity of the surface (values of water contact angles are 32–58°). The etch duration (30 min or 120 min) significantly affects the morphology, topography, wettability and free surface energy for the HCl/H2SO4 and NH4OH/H2O2 etched samples, but has almost no effect on surface composition.

scholarly journals Mechanical behaviour of acetylated rubber wood subjected to artificial weathering

Holzforschung ◽  
2019 ◽  
Vol 73 (11) ◽  
pp. 1005-1016 ◽  
Author(s):  
Samuel Oluyinka Olaniran ◽  
Cabane Etienne ◽  
Tobias Keplinger ◽  
Babatola Olufemi ◽  
Markus Rüggeberg
Keyword(s):  
Mechanical Properties ◽  
Reaction Times ◽  
Colour Change ◽  
Middle Lamella ◽  
Weight Percent ◽  
Mechanical Tests ◽  
Native Form ◽  
Rubber Wood ◽  
Strain Pattern ◽  
Over Exploitation

Abstract Rubber wood utilization in Nigeria has become a viable alternative because of over-exploitation of more durable species. The use of rubber wood in its native form has some disadvantages including dimensional instability, low durability and susceptibility to weathering in outdoor uses. However, it may be improved through chemical modification such as acetylation. In this study, we revealed the effectiveness of acetylation on the protection of rubber wood against weathering in terms of weight loss (WL), colour change, lignin degradation, and mechanical properties. Acetylation was carried out using two different reaction times to achieve weight percent gains (WPG) of around 7% and 10%. Understanding of the effect of acetylation and subsequent weathering on mechanical properties was enabled by analysing wood chemistry with Fourier transform infrared (FTIR) analysis and Raman spectroscopy. The mechanical tests of weathered unmodified and acetylated rubber wood revealed a decrease of tensile stiffness of the unmodified samples as a function of weathering time, while stiffness was retained for the acetylated samples. Weathered unmodified samples showed a bi-phasic stress-strain pattern with a high strain at breakage indicating a slippage of fibres under stress due to degradation of the middle lamella. This was hardly visible for acetylated samples. Thus, acetylation was shown to be effective for protecting rubber wood used in outdoor conditions.

Mechanical Study and Microscopic Characterization of Lignin/PE Composites

2011 ◽  
Vol 335-336 ◽  
pp. 191-194 ◽  
Author(s):  
Xin Ying Lv ◽  
Zhen Hua Gao ◽  
Yan Hua Zhang ◽  
Ming Wei Di
Keyword(s):  
Tensile Properties ◽  
Weight Ratio ◽  
Mechanical Tests ◽  
Electron Microscopic ◽  
Mechanical Study ◽  
Scanning Electron Microscopic ◽  
Compatibilizing Agent ◽  
Scanning Electron

The lignin/PE composites with different compatibilizing agents were extruded and the tensile properties have been tested. The weight ratio of PE, ligin and PE-a-MAH were 7.5%, 10%and 12.5wt%; the weight ratio of PE, ligin and PP-a-MAH were 5%, 7.5% and 10wt% respectively. Scanning Electron Microscopic (SEM) was used to characterize the morphology of the composites. The tensile strengths of lignin/PE composites with PE-g-MAH were higher than that one with PP-g-MAH. Both of them were higher than that one without any compatibilizing agent. And PE-g-MAH was the better compatibilizing agent confirmed by the mechanical tests and SEM results.

scholarly journals Effect of an Ionic Liquid on the Flexural and Fracture Mechanical Properties of EP/MWCNT Nanocomposites

2017 ◽  
Vol 885 ◽  
pp. 19-24 ◽  
Author(s):  
Gábor Szebényi ◽  
Levente Ferenc Tóth ◽  
József Karger-Kocsis
Keyword(s):  
Ionic Liquid ◽  
Interfacial Adhesion ◽  
Bending Strength ◽  
Mechanical Tests ◽  
Critical Force ◽  
Electron Microscopic ◽  
Adhesion Promoter ◽  
Multiwalled Carbon ◽  
Three Point Bending ◽  
Bending Modulus

The improvement of interfacial adhesion between multiwalled carbon nanotubes (MWCNTs) and epoxy resin (EP) was investigated in nanocomposites with the addition of an ionic liquid (IL, 1-Ethyl-3-methyl imidazolium tetrafluoroborate - EMIM BF4) as interfacial adhesion promoter. MWCNT (0, 0.3 and 0.5 weight%) was dispersed in EP through diluting an MWCNT-rich masterbatch prepared in presence and absence of IL. Three point bending and compact tension (CT) fracture mechanical tests were performed on specimens with different MWCNT contents with and without IL surfactant. IL addition resulted in easier dispersion of MWCNT in the EP masterbatch. With the addition of the IL the three point bending strength, the bending modulus of elasticity and the critical force required for crack propagation have increased significantly at the optimal, 0.3 weight% MWCNT content. Scanning electron microscopic (SEM) investigation of the fracture surfaces of the CT specimens revealed that incorporation of MWCNTs and its IL-assisted dispersion produced rougher surfaces suggesting higher fracture toughness than the reference EP.

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