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Nanomaterials (Basel, Switzerland) Mar 2022Binary and ternary composites (CM) based on M-type hexaferrite (HF), polymer matrix (PVDF) and carbon nanomaterials (quasi-one-dimensional carbon nanotubes-CNT and...
Binary and ternary composites (CM) based on M-type hexaferrite (HF), polymer matrix (PVDF) and carbon nanomaterials (quasi-one-dimensional carbon nanotubes-CNT and quasi-two-dimensional carbon nanoflakes-CNF) were prepared and investigated for establishing the impact of the different nanosized carbon on magnetic and electrodynamic properties. The ratio between HF and PVDF in HF + PVDF composite was fixed (85 wt% HF and 15 wt% PVDF). The concentration of CNT and CNF in CM was fixed (5 wt% from total HF + PVDF weight). The phase composition and microstructural features were investigated using XRD and SEM, respectively. It was observed that CM contains single-phase HF, γ- and β-PVDF and carbon nanomaterials. Thus, we produced composites that consist of mixed different phases (organic insulator matrix-PDVF; functional magnetic fillers-HF and highly electroconductive additives-CNT/CNF) in the required ratio. VSM data demonstrate that the main contribution in main magnetic characteristics belongs to magnetic fillers (HF). The principal difference in magnetic and electrodynamic properties was shown for CNT- and CNF-based composites. That confirms that the shape of nanosized carbon nanomaterials impact on physical properties of the ternary composited-based magnetic fillers in polymer dielectric matrix.
PubMed: 35269356
DOI: 10.3390/nano12050868 -
RSC Advances Oct 2021There is a growing interest in replacing fossil-based polymers and composites with more sustainable and renewable fully biobased composite materials in automotive,... (Review)
Review
There is a growing interest in replacing fossil-based polymers and composites with more sustainable and renewable fully biobased composite materials in automotive, aerospace and marine applications. There is an effort to develop components with a reduced carbon footprint and environmental impact, and materials based on biocomposites could provide such solutions. Structural components can be subjected to different marine conditions, therefore assessment of their long-term durability according to their marine applications is necessary, highlighting related degradation mechanisms. Through an up-to-date review, this work critically discusses relevant literature on the long-term durability of biocomposites specific for marine environments. Importantly, in this review we report the effects of abiotic parameters, such as the influence of hygrothermal exposures (temperatures and UV radiation) on physical, mechanical and thermal characteristics of biocomposites. Furthermore, we identify and discuss the potential ecotoxicological effects of leaching substances and microplastics derived from biocomposites, as well as the change in mechanical, physical and thermal behaviours correlated to degradation in the fibre matrix interface, surface defects and overall deterioration of the composite's properties. Finally, the combined effects of various environmental exposures on the long-term durability of the biocomposites are critically reviewed.
PubMed: 35493549
DOI: 10.1039/d1ra03023j -
Molecules (Basel, Switzerland) Dec 2023Pectin has recently drawn much attention in biomedical applications due to its distinctive chemical and biological properties. Polymers like pectin with cell-instructive... (Review)
Review
Pectin has recently drawn much attention in biomedical applications due to its distinctive chemical and biological properties. Polymers like pectin with cell-instructive properties are attractive natural biomaterials for tissue repair and regeneration. In addition, bioactive pectin and pectin-based composites exhibit improved characteristics to deliver active molecules. Pectin and pectin-based composites serve as interactive matrices or scaffolds by stimulating cell adhesion and cell proliferation and enhancing tissue remodeling by forming an extracellular matrix in vivo. Several bioactive properties, such as immunoregulatory, antibacterial, anti-inflammatory, anti-tumor, and antioxidant activities, contribute to the pectin's and pectin-based composite's enhanced applications in tissue engineering and drug delivery systems. Tissue engineering scaffolds containing pectin and pectin-based conjugates or composites demonstrate essential features such as nontoxicity, tunable mechanical properties, biodegradability, and suitable surface properties. The design and fabrication of pectic composites are versatile for tissue engineering and drug delivery applications. This article reviews the promising characteristics of pectin or pectic polysaccharides and pectin-based composites and highlights their potential biomedical applications, focusing on drug delivery and tissue engineering.
Topics: Pectins; Biocompatible Materials; Tissue Scaffolds; Tissue Engineering; Polymers
PubMed: 38138464
DOI: 10.3390/molecules28247974 -
Materials (Basel, Switzerland) Oct 2021Dense TiSiC/ZnO composites were sintered at different temperatures by spark plasma sintering (SPS). The effects of sintering temperature on composition and mechanical...
Dense TiSiC/ZnO composites were sintered at different temperatures by spark plasma sintering (SPS). The effects of sintering temperature on composition and mechanical properties of TiSiC/ZnO composites were studied. The tribological behaviors of TiSiC/ZnO composites/Inconel 718 alloy tribo-pairs at elevated temperature from 25 °C to 800 °C were discussed. The experimental results showed that the initial decomposition temperature of the TiSiC/ZnO composite was 1150 °C, and TiSiC decomposed into TiC. When the decomposition temperature was higher than 1150 °C, the compositions of the TiSiC/ZnO composites were TiSiC, ZnO, and TiC. It was found that TiSiC/ZnO composites had better self-lubricating performance than TiSiC at elevated temperature from 600 °C to 800 °C, which was owing to material transfers of tribo-pairs and sheared oxides generated by tribo-oxidation reactions.
PubMed: 34683680
DOI: 10.3390/ma14206088 -
Advances in Colloid and Interface... Aug 2021Homoaggregation of dispersed particles, i.e., aggregation of particles of the same shape, charge, size, and composition, is a well-studied field and various theoretical... (Review)
Review
Homoaggregation of dispersed particles, i.e., aggregation of particles of the same shape, charge, size, and composition, is a well-studied field and various theoretical and experimental approaches exist to understand the major phenomena involved in such processes. Besides, heteroaggregation of particles, i.e., aggregation of particles of different shape, charge, size, or composition, has attracted widespread interest due to its relevance in various biomedical, industrial, and environmental systems. For instance, heteroaggregation of plastic contaminant particles with naturally occurring solid materials in waters (e.g., clays, silica and organic polymers) plays an important role in the decontamination technologies. Moreover, nanofabrication processes involving heteroaggregation of particles to prepare novel composite materials are widely implemented in fundamental science and in more applied disciplines. In such procedures, stable particle dispersions are mixed and the desired structure forms owing to the presence of interparticle forces of various origins, which can be tuned by performing appropriate surface functionalization as well as altering the experimental conditions. These composites are widely used in different fields from sensing through catalysis to biomedical delivery. The present review summarizes the recent progresses in the field including new findings regarding the basic principles in particle heteroaggregation, preparation strategies of heteroaggregated structures of different morphology, and the application of the obtained hybrid composites. Such information will be very helpful to those involved in the design of novel composites consisting of different nano or colloidal particles.
Topics: Pharmaceutical Preparations; Polymers; Silicon Dioxide
PubMed: 34107320
DOI: 10.1016/j.cis.2021.102456 -
Polymers Nov 2022Multi-structural polymer composites are widely used in the mechanical engineering, automotive, aviation and oil refining industries, as well as in the printing industry...
Multi-structural polymer composites are widely used in the mechanical engineering, automotive, aviation and oil refining industries, as well as in the printing industry as a shock-absorbing deckle on the offset cylinders of printing machines. During offset printing, composites come into contact with inks and washing solutions, the components of which penetrate the material and cause the polymers to swell. This process degrades the print quality, and for this reason the study of its features is relevant. The prerequisites for this work are the study of the fundamental laws of diffusion and sorption of liquids by polymers with different micro- and macro-structures in different physical states and in different forms (e.g., films, sheets, fibers and fabrics). The combination of polymer materials in the composition of multi-structural fabric blankets makes it possible to obtain materials with unique mechanical properties and high resistance to liquid penetrating media and to use them in high-tech processes of multi-color printing with high resolution and color rendering. This article reports for the first time the kinetics and thermodynamics results obtained from the swelling of multi-structural polymeric blankets in solvents used in printing, and the effect of sorption of different polar liquids on the viscoelastic strain under compression during the operation of the damping systems of printing machines. Using mathematical models of activated liquid diffusion in polymers and deformation of a viscoelastic body, the swelling rate constants, solvent diffusion coefficients (the kinetic characteristics of the swelling process) and Flory−Huggins parameters (the thermodynamic characteristics of the interaction of the solvent with the composite) for composite−solvent systems with several chemical composition variants were determined. The elastic modulus and the viscosity coefficient of the composite under liquid saturation were calculated based on the experimental cyclic compression data. The range of change in the compression and restoration times of the polymeric blankets (0.09 s ÷ 0.78 s) was determined. It was shown that the composite swelled to a limited extent in all the studied liquids. All solvents used were thermodynamically poor (χ > 0.5). It has been established that rubber−fabric blankets coated with nitrile rubber are the least resistant to the action of dichloroethane, and that blankets with layers of polyolefins are not resistant to ethyl acetate. Water significantly affects the physicochemical properties of rubber−fabric blankets with a large proportion of cotton fabric layers. The data obtained can serve as a basis for optimizing the compositions of inks and cleaning solutions, as well as a theoretical basis for the thermodynamics of composite−solvent systems.
PubMed: 36501569
DOI: 10.3390/polym14235177 -
Scientific Reports May 2022Human teeth are mechanically robust through a complex structural composite organisation of materials and morphology. Efforts to replicate mechanical function in...
Human teeth are mechanically robust through a complex structural composite organisation of materials and morphology. Efforts to replicate mechanical function in artificial teeth (typodont teeth), such as in dental training applications, attempt to replicate the structure and morphology of real teeth but lack tactile similarities during mechanical cutting of the teeth. In this study, biomimetic typodont teeth, with morphology derived from X-ray microtomography scans of extracted teeth, were 3D printed using an approach to develop novel composites. These composites with a range of glass, hydroxyapatite and porcelain reinforcements within a methacrylate-based photopolymer resin were compared to six commercial artificial typodont teeth. Mechanical performance of the extracted human teeth and 3D printed typodont teeth were evaluated using a haptic approach of measuring applied cutting forces. Results indicate 3D printed typodont teeth replicating enamel and dentine can be mechanically comparable to extracted human teeth despite the material compositions differing from the materials found in human teeth. A multiple parameter variable of material elastic modulus and hardness is shown to describe the haptic response when cutting through both human and biomimetic, highlighting a critical dependence between the ratio of material mechanical properties and not absolute material properties in determining tooth mechanical performance under the action of cutting forces.
Topics: Biomimetics; Composite Resins; Durapatite; Humans; Materials Testing; Printing, Three-Dimensional; Tooth; X-Ray Microtomography
PubMed: 35550557
DOI: 10.1038/s41598-022-11658-y -
The Journal of Advanced Prosthodontics Feb 2017The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded...
PURPOSE
The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite.
MATERIALS AND METHODS
Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of 10 × 10 × 4 mm. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at 37℃ and cut into microbars with the dimension of 1 × 1 × 8 mm. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at α = .05.
RESULTS
Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments.
CONCLUSION
Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite.
PubMed: 28243390
DOI: 10.4047/jap.2017.9.1.38 -
Journal of Biomedical Materials... Nov 2019Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary... (Review)
Review
Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary reason both composite and amalgam restorations fail is recurrent decay, for which composite restorations experience a 2.0-3.5-fold increase compared to amalgam. Recurrent decay is a pernicious problem-the standard treatment is replacement of defective composites with larger restorations that will also fail, initiating a cycle of ever-larger restorations that can lead to root canals, and eventually, to tooth loss. Unlike amalgam, composite lacks the inherent capability to seal discrepancies at the restorative material/tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal the interface, but the adhesive degrades, which can breach the composite/tooth margin. Bacteria and bacterial by-products such as acids and enzymes infiltrate the marginal gaps and the composite's inability to increase the interfacial pH facilitates cariogenic and aciduric bacterial outgrowth. Together, these characteristics encourage recurrent decay, pulpal damage, and composite failure. This review article examines key biological and physicochemical interactions involved in the failure of composite restorations and discusses innovative strategies to mitigate the negative effects of pathogens at the adhesive/dentin interface. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2466-2475, 2019.
Topics: Adhesives; Dental Materials; Dental Restoration, Permanent; Dentin; Humans
PubMed: 30895695
DOI: 10.1002/jbm.b.34358 -
Materials (Basel, Switzerland) Mar 2022In this paper, the 12k T-700 Multiaxial-Warp-Knitting-Needle (MWK-N) C/SiC composite and pin were designed and fabricated using the isothermal chemical vapor...
In this paper, the 12k T-700 Multiaxial-Warp-Knitting-Needle (MWK-N) C/SiC composite and pin were designed and fabricated using the isothermal chemical vapor infiltration (ICVI) method. The composite's microstructure and mechanical properties were examined by subjection to tensile and interlaminar shear tests. Three types of double-shear tests were conducted for C/SiC pins, including shear loading perpendicularly, along, and at 45° off-axial to the lamination. The fracture surface of the tensile and shear failure specimens was observed under scanning electronic microscope (SEM). The relationships between the composite's microstructure, mechanical properties, and damage mechanisms were established. The composite's average tensile strength was σ = 68.3 MPa and the average interlaminar shear strength was τ = 38.7 MPa. For MWK-N-C/SiC pins, the double-shear strength was τ = 76.5 MPa, 99.7 MPa, and 79.6 MPa for test types I, II, and III, respectively. Compared with MWK-C/SiC pins, the double-shear strength of MWK-N-C/SiC pins all decreased, i.e., 26.7%, 50.8%, and 8% for test types I, II, and III, respectively. The MWK-N-C/SiC composite and pins possessed high interlaminar shear strength and double-shear strength, due to the needled fiber in the thickness direction, low porosity (10-15%), and high composite density (2.0 g/cm).
PubMed: 35329789
DOI: 10.3390/ma15062338