scholarly journals Mechanical properties of highly porous PEEK bionanocomposites incorporated with carbon and hydroxyapatite nanoparticles for scaffold applications

2019 ◽  
Vol 8 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Md. Nizam Uddin ◽  
Puttagounder S. Dhanasekaran ◽  
Ramazan Asmatulu
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Pore Size ◽  
Mechanical Tests ◽  
Bone Diseases ◽  
Filler Materials ◽  
Test Results ◽  
Micro Computed Tomography ◽  
Carbon Particles ◽  
Highly Porous

Abstract Bone regeneration is of great importance worldwide, because of various bone diseases, such as infections, tumors, and resultant fracture, birth defects, and bone loss due to trauma, explosion, or accident. Bone regeneration can be achieved by several materials and templates manufactured through various fabrication techniques. Uses of different materials and scaffold fabrication techniques have been explored over the past 20 years. In this research, polyetheretherketone (PEEK) was used to fabricate highly porous bionanocomposite foams for bone scaffolding. Melt casting and salt porogen (200–500 µm size) leaching methods were adapted to create an adequate pore size and the necessary percent of porosity, because pore size plays a vital role in cell implantation and growth. Porosity (75% and 85%) of the prepared scaffolds was adjusted by changing salt concentrations in the PEEK powder. Hydroxyapatite (HA) and carbon particles were used to improve cell attachments and interactions with the porous PEEK and to increase the mechanical properties of the scaffold materials. Carbon fiber (CF) and carbon nanotubes (CNTs) were uniformly dispersed into the PEEK powder before melt casting to enhance the mechanical properties and to observe the influence of the carbon particles on the properties of PEEK bionanocomposite foam. Compression test results of the fabricated bionanocomposites showed that HA and carbon particles are the potential filler materials for the enhancement of bionanocomposite mechanical properties. About 186% enhancement of compression modulus and 43% enhancement of yield strength were observed while incorporating only 0.5 wt% of CNTs into PEEK/HA bionanocomposites having 75% porosity, compared to PEEK/HA 20 wt% bionanocomposites. Micro-computed tomography (micro-CT) test results reveal that pore size and interconnectivity of the nanocomposite foams are in order and within the designed sizes. Mechanical tests proved that PEEK bionanocomposite foam has the potential for use in bone scaffolding and other biomedical applications.

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

scholarly journals Effect of Melt-Derived Bioactive Glass Particles on the Properties of Chitosan Scaffolds

2019 ◽  
Vol 10 (3) ◽  
pp. 38 ◽  
Author(s):  
Hamasa Faqhiri ◽  
Markus Hannula ◽  
Minna Kellomäki ◽  
Maria Teresa Calejo ◽  
Jonathan Massera
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bioactive Glass ◽  
Pore Size ◽  
Glass Content ◽  
Micro Computed Tomography ◽  
Glass Composite ◽  
Composite Scaffolds ◽  
Bioactive Glasses

This study reports on the processing of three-dimensional (3D) chitosan/bioactive glass composite scaffolds. On the one hand, chitosan, as a natural polymer, has suitable properties for tissue engineering applications but lacks bioactivity. On the other hand, bioactive glasses are known to be bioactive and to promote a higher level of bone formation than any other biomaterial type. However, bioactive glasses are hard, brittle, and cannot be shaped easily. Therefore, in the past years, researchers have focused on the processing of new composites. Difficulties in reaching composite materials made of polymer (synthetic or natural) and bioactive glass include: (i) The high glass density, often resulting in glass segregation, and (ii) the fast bioactive glass reaction when exposed to moisture, leading to changes in the glass reactivity and/or change in the polymeric matrix. Samples were prepared with 5, 15, and 30 wt% of bioactive glass S53P4 (BonAlive ®), as confirmed using thermogravimetric analysis. MicrO–Computed tomography and optical microscopy revealed a flaky structure with porosity over 80%. The pore size decreased when increasing the glass content up to 15 wt%, but increased back when the glass content was 30 wt%. Similarly, the mechanical properties (in compression) of the scaffolds increased for glass content up to 15%, but decreased at higher loading. Ions released from the scaffolds were found to lead to precipitation of a calcium phosphate reactive layer at the scaffold surface. This is a first indication of the potential bioactivity of these materials. Overall, chitosan/bioactive glass composite scaffolds were successfully produced with pore size, machinability, and ability to promote a calcium phosphate layer, showing promise for bone tissue engineering and the mechanical properties can justify their use in non-load bearing applications.

scholarly journals Effect of Pore Structure on Thermal Conductivity and Mechanical Properties of Autoclaved Aerated Concrete

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 339
Author(s):  
Gonglian Chen ◽  
Fenglan Li ◽  
Pengfei Jing ◽  
Jingya Geng ◽  
Zhengkai Si
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Pore Structure ◽  
Pore Size ◽  
Base Material ◽  
Test Results ◽  
Foam Stabilizer ◽  
Base Materials ◽  
Aerated Concrete

With the premise of investigating mechanical properties, the thermal conductivity of autoclaved aerated concrete (AAC) is a key index of self-insulation block walls for building energy conservation. This study focused on the effect of pore structures on the mechanical performance and thermal conductivity of AAC with the comparison of AAC base materials. Different kinds of AAC and their base materials were prepared and experimentally investigated. While maintaining a consistent mix proportion of the AAC base material, the pore structure of AAC was changed by the dosage of aluminum power/paste, foam stabilizer, and varying the stirring time of aluminum paste. The steam curing systems of AAC and the base material were determined based on SEM (Scanning Electronic Microscopy) and XRD (X-Ray Diffraction) tests. With almost the same apparent density, the pore size decreased with the increasing content of foam stabilizer, and the mixing time of aluminum paste and foam stabilizer has a great influence on pore size. The thermal conductivity test and compressive test results indicated that that pore size had an effect on the thermal conductivity, but it had little effect on the compressive strength, and the thermal conductivity of sand aeration AAC was 8.3% higher than that of fly ash aeration AAC; the compressive strength was 10.4% higher, too. With almost the same apparent density, the regression mathematical model indicates that the thermal conductivity of AAC increased gradually with the increase of pore size, but it had little effect on the compressive strength. From the test results of basic mechanical properties, the mechanical model of cubic compressive strength, elastic modulus, axial compressive strength, and splitting tensile strength was obtained. The proposed stress–strain relationship model could well describe the relationship of AAC and the base material at the rising section of the curve.

Particleboard Manufactured with Variation of Press Time

2015 ◽  
Vol 1088 ◽  
pp. 644-647
Author(s):  
Cristiane Inácio de Campos ◽  
Bruno Santos Ferreira ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Juliana Cortez Barbosa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Test Results ◽  
Thickness Swelling ◽  
Mean Values ◽  
Tukey Test ◽  
Press Time ◽  
Brazilian Standard

This research aimed to produce and determine physical and mechanical properties of three-layered particleboard produced with Pinussp. wood particlesand three different times of press, i.e., 3, 5 and 7 minutes. Recommendations of the Brazilian standard ABNT NBR 14810 [1] were adopted to fundament physical and mechanical tests. The properties evaluated were the modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending; internal bond; thickness swelling; water absorption; moisture content and apparent density.The mean values showed, for the physical properties, that all the panels manufactured achievedthe requirements of theBrazilian standard, and for mechanical properties, only the panelsmanufacturedwith 7minutesofpressing timemet therequirements. From the Tukey test results, timesof the pressingcycleinfluencedsignificantlyin allinvestigatedphysical and mechanicalproperties, showed better results the panels madewithseven minutesof the pressingcycle, implyingthat the time ofseven minutesof the pressingcycle is thebest among theinvestigatedperiodsin the manufactureofparticleboard.

Experimental Study on Mechanical Properties of Steel and Polypropylene Fiber-Reinforced Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1355-1361 ◽  
Author(s):  
Liang Shan ◽  
Liang Zhang
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Mechanical Tests ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Polypropylene Fiber Reinforced Concrete

The mechanical tests of normal concrete (NC) specimens, steel fiber reinforced concrete (SFRC) specimens and polypropylene fiber reinforced concrete (PPFRC) specimens have been carried out. Fiber-reinforced concretes containing different volume fraction and aspect ratio of steel and polypropylene fibers were compared in terms of compressive, splitting tensile, ultimate tensile properties. Test results indicate that the mechanical properties of NC can be improved by addition of steel fibers and can be enhanced with the increase of fiber content. However, polypropylene fiber may cause opposite effect, if volume fraction too high.

scholarly journals Evaluation of Mechanical Properties of GFRP Composites with Fillers

2019 ◽  
Vol 8 (11) ◽  
pp. 3997-4001
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Environmental Conditions ◽  
Mechanical Tests ◽  
Flexural Properties ◽  
Filler Materials ◽  
Gfrp Composites ◽  
Gfrp Composite ◽  
The Matrix ◽  
Day By Day

The usage of GFRP composites are gradually increasing day by day because of its unique properties over conventional metals. GFRP composite materials are much stronger and contain less weight than the metals which are using in more industries like Automobiles. And it was noticed that the properties of the GFRP composites are decreasing noticeably in certain environmental conditions. So, it is important to improve the quality and mechanical properties of the GFRP composites that they use to odder environmental conditions. From the farmer literature it was observed that adding filler materials to the composite adhesive can enhance the strength and properties of the composite material. In this investigation two filler materials (Znso4, talc) are added to the composites in certain ratios (1%,3%,5% and 7%). And to observe the mechanical properties specimens are placed in water for 30 days, and mechanical tests were performed on the specimens. And It was observed when fillers are added to the matrix of the composite the mechanical properties are increased when it compares to the no filler added composites. Properties are enhanced when the certain ratio of filler were added. Again properties are decreased when the high amount of fillers were added. And high tensile properties were observed when the 3% of filler added. And flexural properties and ILSS properties are enhanced when 1% of filler added.

A Novel Biodegradable Poly(Lactic-Co-Glycolic Acid) Foam for Bone Regeneration

1993 ◽  
Vol 331 ◽  
Author(s):  
Robert C. Thomson ◽  
Michael J. Yaszemski ◽  
John M. Powers ◽  
Antonios G. Mikos
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Composite Material ◽  
Bone Regeneration ◽  
Pore Size ◽  
Glycolic Acid ◽  
Average Molecular Weight ◽  
Gelatin Microspheres ◽  
Degradable Polymer ◽  
Biodegradable Poly

AbstractWe present a novel method for manufacturing three-dimensional, biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) foam scaffolds for use in bone regeneration. The technique involves the formation of a composite material consisting of gelatin microspheres surrounded by a PLGA matrix. The gelatin microspheres are leached out leaving an open-cell foam with a pore size and morphology defined by the gelatin microspheres. The foam porosity can be controlled by altering the volume fraction of gelatin used to make the composite material. PLGA 50:50 was used as a model degradable polymer to establish the effect of porosity, pore size, and degradation on foam mechanical properties. The compressive strengths and moduli of PLGA 50:50 foams were found to decrease with increasing porosity but were largely unaffected by pore size. Foams with compressive strengths up to 2.5 MPa were manufactured. From in vitro degradation studies we established that for PLGA 50:50 foams the mechanical properties declined in parallel with the decrease in molecular weight. Below a weight average molecular weight of 10,000 the foam had very little mechanical strength (0.02 MPa). These results indicate that PLGA 50:50 would not be suitable as a scaffold material for bone regeneration. However, the dependence of mechanical properties on porosity, pore size, and degree of degradation which we have determined will aid us in designing a PLGA foam (with a comonomer ratio other than 50:50) suitable for bone regeneration.

Unconfined Compressive and Splitting Tensile Strength of Dredged Sediments Stabilized with Cement and Fly Ash

2020 ◽  
Vol 856 ◽  
pp. 367-375
Author(s):  
Hatairat Poorahong ◽  
Nunthanis Wongvatana ◽  
Pitthaya Jamsawang ◽  
Kamolwan Lueprasert ◽  
Kullachai Tantayopin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Building Materials ◽  
Mechanical Tests ◽  
Splitting Tensile Strength ◽  
Type I ◽  
Test Results ◽  
Dredged Sediments

The main objective of this study is to investigate the mechanical properties of dredged sediments, which are considered as waste from the process of removing sediments from the bottom of a dam's reservoir. The dredged sediments with stabilization can to be reused as construction and building materials in civil engineering works. The mechanical tests included unconfined compressive strength (UCS) and splitting tensile strength (STS) to understand the behavior of the dredged sediments stabilized with ordinary portland cement (OPC) type I and fly ash (FA). The overall test results indicated that OPC type I and FA were effective in stabilizing the sampled dredged sediments from two dams in northern Thailand. The stabilization with 10% FA content was found to be most effective for improving mechanical properties of the stabilized samples.

The Impact of Mineral Fillers on the Mechanical and the Thermal Properties of Polyester

2014 ◽  
Vol 600 ◽  
pp. 783-791
Author(s):  
Khaled M. Shokry
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Cost Reduction ◽  
Polyester Resin ◽  
Filler Materials ◽  
Test Results ◽  
Polyester Resins ◽  
Quantitative Measurements ◽  
Mineral Fillers ◽  
The Impact

Polyester resins has found a wide spread in many applications. Filler materials are used extensively with polyester resin for a variety of reasons like cost reduction, and more importantly to enhance some physical and/or mechanical properties. Through the present work several types of inorganic fillers (cement, silica fume, and sand) were incorporated into the polyester resin. Their effects on the mechanical and the thermal properties were investigated. Quantitative measurements and qualitative observations were made to recognize the different aspects related to their employment in attempt to find an appropriate means to enhance a prescribed property. Test results revealed that although a pronounced enhancement of the mechanical properties was achieved, but a specific filler type may not has the same effect on each mechanical property. Therefore, in real applications where only some of the properties are of concern, the proper filler type and content should be specified accordingly. Anyhow, employing a combination of filler types (mixed fillers) is an efficient way to utilize the benefits of each of the employed fillers.

Physiochemical characterization and biological effect of anorganic bovine bone matrix and organic-containing bovine bone matrix in comparison with Bio-Oss in rabbits

2018 ◽  
Vol 33 (4) ◽  
pp. 566-575 ◽  
Author(s):  
Yan-Pin Fan ◽  
Jian-Feng Lu ◽  
An-Tian Xu ◽  
Fu-Ming He
Keyword(s):  
Bone Regeneration ◽  
Pore Size ◽  
Surface Area ◽  
Pore Volume ◽  
Biological Effects ◽  
Bone Matrix ◽  
Clinical Applications ◽  
Organic N ◽  
Bovine Bone ◽  
Micro Computed Tomography

Bovine origin matrix has been widely used in clinical applications and investigated by various research institutions. However, the potential factors that influence bone regeneration are still not thoroughly understood and need further investigations. In this study, bone regeneration properties of anorganic bovine bone matrix (ABBM), organic-containing bovine bone matrix (OBBM), and widely acknowledged anorganic bovine bone matrix (Bio-Oss) were compared. Besides, the correlations between physiochemical characterizations and bone regeneration properties of the three xenografts were also investigated. Physiochemical characterizations were measured by special instrumentations. In animal studies, the three xenografts were implanted into 8-mm-diameter cranial defects of 16 New Zealand white rabbits. The biological effects were evaluated by micro-computed tomography and histomorphometric analysis after 6 and 12 weeks of implantation. The physical characterizations showed that anorganic bovine bone matrix and Bio-Oss had more nanostructures, larger surface area, bigger pore volume, and bigger pore size than that of organic-containing bovine bone matrix. The chemical characterizations showed that anorganic bovine bone matrix and Bio-Oss had higher crystallinity than that of organic-containing bovine bone matrix, and organic-containing bovine bone matrix contained organic nitrogen (N) component. In vivo, anorganic bovine bone matrix and Bio-Oss possessed better bone regeneration properties than that of organic-containing bovine bone matrix. Taken together, nanostructures, larger surface area, bigger pore volume, and bigger pore size of xenografts played an active role in new bone formation. Besides, lower crystallinity and organic N element of xenografts produced a positive effect on graft degradation. The abovementioned findings could provide theoretical basis for better choice in clinical applications and better manufacturing hydroxyapatite-derived bone graft in the future.

Sign in / Sign up

Export Citation Format

Share Document