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The adsorption efficiency of Cr(VI) and anionic textile dyes onto MgAl-layered double hydroxides (LDHs) and MgAl-LDH coated on bio-silica (b-SiO2) nanoparticles (MgAl-LDH@SiO2) derived from waste rice husks was studied in this work. The material was characterized using field-emission scanning electron microscopy (FE-SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopic (XPS) techniques. The adsorption capacities of MgAl-LDH@SiO2 were increased by 12.2%, 11.7%, 10.6%, and 10.0% in the processes of Cr(VI), Acid Blue 225 (AB-225), Acid Violet 109 (AV-109), and Acid Green 40 (AG-40) dye removal versus MgAl-LDH. The obtained results indicated the contribution of b-SiO2 to the development of active surface functionalities of MgAl-LDH. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for dye removal, while surface complexation dominates in the processes of Cr(VI) removal. The disposal of effluent water after five adsorption/desorption cycles was attained using enzymatic decolorization, photocatalytic degradation of the dyes, and chromate reduction, satisfying the prescribed national legislation. Under optimal conditions and using immobilized horseradish peroxidase (HRP), efficient decolorization of effluent solutions containing AB-225 and AV-109 dyes was achieved. Exhausted MgAl-LDH@SiO2 was processed by dissolution/precipitation of Mg and Al hydroxides, while residual silica was used as a reinforcing filler in polyester composites. The fire-proofing properties of composites with Mg and Al hydroxides were also improved, which provides a closed loop with zero waste generation. The development of wastewater treatment technologies and the production of potentially marketable composites led to the successful achievement of both low environmental impacts and circular economy implementation. [ABSTRACT FROM AUTHOR]

Highlights Dental materials' demands can be answered using composite materials, as composite properties are suitable for tailoring the material's behavior. Poly (methyl methacrylate) (PMMA) is usually a material of choice in dental applications, and its mechanical properties can be improved in terms of modulus, strength, and hardness. The chosen reinforcement in this publication was Zn/Al‐layered double hydroxide (LDH), as this material has functional property modification possibilities. The reinforcement was synthesized using the coprecipitation process on a laboratory scale. The dispersion of the reinforcement was done with ultrasonication, and the composites prepared contained 1, 3, and 5 wt% of reinforcement, and the so‐prepared composites were compared to the matrix. Improvements were observed in terms of the elastic modulus and tensile strength, and the best performance was observed in the composite with 3 wt% of particles. Hardness increased with the addition of particles and the higher the particle content, the better the hardness. Materials were tested using dynamic mechanical techniques, and it was proven that the addition of particles lowers the Tg of the composite compared to the pure matrix. The addition of particles diminished the affinity of the material for polar liquids such as water. Zn/Al‐layered double hydroxide is used to reinforce acrylic matrix. Composite with improved strength, modulus, and microhardness. Addition of a layered double hydroxide decreases hydrophobicity of composite. [ABSTRACT FROM AUTHOR]

Acrylate polymers are used in several applications such as dentistry, medicine, and industry. The modification of their properties using the reinforcement is of key importance for the possible applications. Layered double hydroxides are materials that are easily synthesized by several techniques giving the possibility to modulate the chemical composition and morphology of the reinforcement and they consist of a divalent and a trivalent anion hydroxide and the layers can be exfoliated and thus provide a material interesting for composite reinforcement. In this paper, Mn was used as a divalent and Al as a trivalent cation. The obtained particles were used as reinforcement for the preparation of composites in 1, 3, and 5 wt% quantities and prepared samples were compared to the matrix consisting of PMMA. Physical mechanical properties of the sample having the best mechanical properties (with 3 wt% of MnAl‐LDH filers) exhibited 6.38% modulus of elasticity, 27% hardness, and 10% tensile strength improved values compared to the clear PMMA matrix. Toughness was lowered in this sort of composite compared to the pure matrix. Highlights: MnAl‐LDH‐PMMA composites improved modulus, strength, hardnessLoss of toughness is tolerable for 3 wt% reinforcementViscoelastic properties are improved for composites compared to matrix [ABSTRACT FROM AUTHOR]

Materials from green resources boast a low carbon footprint, forming the foundation of the circular economy approach in materials science. Thus, in this study, waste poly(ethylene terephthalate) (PET) was subjected to depolymerization using propylene glycol (PG), and subsequent polycondensation with bio-based maleic anhydride (MA) produced unsaturated polyester resin (b-UPR). Bio-derived acryloyl-modified Kraft lignin (K f L-A) served as a vinyl reactive filler in the b-UPR matrix to create b-UPR/K f L-A composites. The structural characterization of K f L-A and b-UPR involved the use of FTIR and NMR techniques. The mechanical properties of the newly fabricated composites were assessed through tensile strength, Vickers microhardness, and dynamic mechanical tests. The addition of K f L-A to the rigid b-UPR matrix enhanced material flexibility, resulting in less stiff and hard materials while preserving composite toughness. For instance, incorporating 10 wt% of K f L-A in b-UPR led to a 17% reduction in hardness, a 48% decrease in tensile strength, and a 20% reduction in toughness. Positive environmental impact was achieved by incorporation of 64 wt% of renewable and recycled raw material. Analogously prepared b-UPR/K f L composites showed structural inhomogeneity and somewhat better mechanical properties. Transmission (TEM) and scanning (SEM) electron microscopies revealed a suitable relationship between mechanical and structural properties of composites in relation to the extent of K f L-A addition. The UL94V flammability rating confirmed that flame resistance increased proportionally with the K f L-A addition. Once deposited in a landfill, these composites are expected to disintegrate more easily than PET, causing less harm to the environment and contributing to sustainability in the plastics cycle. [Display omitted] • Unsaturated polyester resin, b-UPR, was obtained from waste PET and biobased materials. • Acryloyl modified lignin, K f L-A, was used as vinyl rective filler in b-UPR composites. • The addition of K f L-A increased flexibility while preserving composite toughness. • The higher addition of K f L-A contribute to increase of fireproofing of the composites. [ABSTRACT FROM AUTHOR]

As a renewable resource, starch is considered to be fully biodegradable and nonpolluting to the environment but the hygroscopicity of starch is the main disadvantage for wider applicability in the production of a polymer‐based material. Hydrophobically modified starch prepared using natural‐based plasticizers/modifiers in a first step ([−]‐diisopropyl D‐tartrate [DiPT], ricinoleic acid [RA] and epoxidized soybean oil [ESO]), and maleated polypropylene (MAPP) in a second step contributed to better compatibility, and thus reinforcing of composites. Tailored processing conditions, structural/morphological properties, hydrophobicity, and water‐resistance of the modified starch were established. In addition, the Charpy impact and tensile strength of composites, based on poly(ethylene‐co‐acrylic acid) (EAA) and modified starches, were determined. Increased tensile strength and Young modulus of the composite using starch‐modified with DiPT‐MAPP, that is, 3 and 83%, respectively, indicated the possible applicability of obtained materials. [ABSTRACT FROM AUTHOR]

Composites based on poly(methyl methacrylate), dimethyl itaconate matrix and alumina particles were prepared. Ferrous oxide-doped alumina particles (Al2O3 Fe) and commercial alumina nanoparticles (Al2O3 n) modified with (3-aminopropyl)trimethoxysilane (AM) and methyl esters of linseed oil fatty acids (biodiesel—BD) were used as reinforcement. The mechanical properties of the prepared composites, containing 1, 3 and 5 wt% of surface-modified alumina particles, are compared to a neat polymer matrix. The particles were characterized by single-beam Fourier transform infrared spectroscopy, thermogravimetry and differential scanning calorimetry. The mechanical properties of the composites were determined by micro-Vickers hardness and impact testing. The morphology of the surface of the composites exposed to cavitation was observed through a field emission scanning electron microscope. AFM analysis was used to compare surface features seen using the SEM and to interpret the surface degradation properties. The hardness, cavitation resistance and high-impact energy resistance of the composites are better in the case of AM surface modification of alumina fillers, but biodiesel modified particles have comparable mechanical properties and a stabilized Al–O–Si bond that could be important when a composite is exposed to humidity or a wet environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composite particles of bio-based silica and MnAlLDH are prepared by coprecipitation. • PMMA matrix is improved in terms of hardness by addition of composite particles. • Resistance to the time dependent load is improved with addition of composite particles. The MgAl-LDH@SiO 2 particles are prepared by the coprecipitation of LDH on silica originating from plants. Particles are of submicron size and are well dispersed in the matrix. Composites consisting of PMMA reinforced with MgAl-LDH@SiO 2 particles have improved hardness and resistance to viscoelastic deformation, as tested by microhardness measurements. [ABSTRACT FROM AUTHOR]

A facile synthesis of POSS reagents was used to obtain different particle morphologies. The cluster morphology was in accordance with the conformation of the hydroxyl groups. Improved thermal stability was obtained by the introduction of cross-linkable groups. A facile synthesis was employed for three polyhedral oligo silsequioxanes (POSS), obtaining incompletely condensed structures with fern-like and cubic morphologies. Proton nuclear magnetic resonance spectroscopy (1H NMR) indicated the successful synthesis of the proposed POSS structures. The hydroxyl groups affected the manner and type of POSS morphology, as seen under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Fourier-transform infrared spectroscopy (FTIR) showed the availability of surface hydroxyl groups that contributed to the formation of a higher amount of char residue, as found from TGA analysis. The highest decomposition temperature (281 °C) and the least char residue were found for a cross-linkable POSS, obtained by esterification of the hydroxyl groups with methacryloyl chloride. [ABSTRACT FROM AUTHOR]

Adhesion behavior between the composite films, consisting of UV cured Bis-GMA (Bisphenol A glycidylmethacrylate)/TEGDMA (triethylene glycol dimethacrylate) as a matrix and the ferrous oxide doped alumina particles, Al2O3 Fe, modified with 3-aminopropyl)tri - methoxysilane (AM) and methyl esters of linseed oil fatty acids (biodiesel - BD) used as a reinforcement, and metallic surface was investigated in this study. Al2O3 Fe-BD particles showed pronounced hydrophobicity and hydrolytic stability of alumina surface. Adhesive and mechanical properties of prepared composites, containing 0.5, 1.5 and 3 wt. % of surface modified Al2O3 Fe-AM and Al2O3 Fe-BD particles, were compared to the neat polymer matrix. Adhesion parameter was evaluated using the micro hardness testing method. The comparison of determined contact angle with adhesive parameter, obtained from micro hardness measurements, was discussed in relation to structural effect of reinforcement used. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to examine the influence of cavitation erosion on the morphology of defects formed on the surfaces of alumina-based materials. The alumina-based samples were exposed to cavitation erosion for 42 min. The damages that occurred were monitored at predefined time intervals by measuring the mass loss and observing the sample surfaces. Digital images of surfaces were processed using an image analysis software package to define morphological characteristics of the damages occurred. The calculated morphological parameters were subjected to analysis by pattern recognition techniques to correlate the appearance of particular morphological characteristics with the behavior of the material during cavitation erosion. The newly established method in describing cavitation erosion which uses pattern recognition approach for treatments of morphological parameters calculated for damages by image analysis tools gave the results efficient for material characterization as the traditional one. Highlights • Surface degradation was monitored via mass loss measurement. • Observation of surface damage destruction was done using image analysis. • Shape parameters of surface defects change during cavitation. • Shape parameters changes are correlated to mass loss measurements. [ABSTRACT FROM AUTHOR]

Alumina based particles were prepared from aluminium chloride hydroxide as starting material by sol-gel technique. One series of particles was doped with ferrous oxide. Both series of particles were calcinated at three different temperatures: 700 °C, 800 °C and 900 °C. Poly(methyl methacrylate), PMMA, was used as a matrix and two different types of alumina based particles were added into the matrix to form the composites. All composites consisted of 3 wt% of alumina based particles. The aim of this study was to examine whether and how the temperature of particle calcination affects the microhardness and mechanical properties of the composite. The particles were characterized by the X-ray diffraction (XRD) and physical absorption methods. The morphology of the composites was examined using a field emission scanning electron microscope (FESEM). The microhardness of composites was measured using a traditional Vickers hardness (HV) method. The mechanical characteristics of obtained composites were determined using tensile test and impact testing. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) has become a widespread modern environmental pollutant. There is an essential need for practical and applicable materials for its attenuation. Therefore, the presented research has focused on metallization of carbon fabric using the silver conductive complex solution to enhance the surface conductivity and mechanical properties of the fabric. With this amplification and improving the mentioned characteristics, lightweight and flexible modified carbon fibers can be applied in many environments. The modification has been performed in three steps: the silver conductive complex synthesis, carbon fabric immersion into a silver complex solution, treating with temperature for silver deposition by annealing. The method used for the metallization of carbon fabrics surface does not require expensive and toxic chemicals or electricity, making the process more ecologically and economically acceptable. One of the advantages of using the method for surface modification is the possibility of usage for other materials, not only for textiles and foils. The examination of the surface structure, electrical, EMI shielding characteristics, and mechanical properties of carbon fabrics modified by silver deposition contributes to the determination of multifunctional properties of materials. Also, the dependence on the improvement of multispectral electromagnetic interference shielding effectiveness (EMI SE) characteristics and mechanical properties of materials on the number of cycles has been determined. The most effective material was carbon fabric modified by five cycles, and average attenuation at an L and S bands was 49.67 dB, and a part of C and full X band was 51.07 dB, caused by better coverage by silver particles, increased density and porosity of deposited layer. Increasing the number of silver deposition cycles improves the physical properties of the modified carbon fabrics, where after five cycles the highest maximum force has been measured (2.26 kN). The material's morphology was studied by scanning electron microscopy with Energy-Dispersive X-ray Spectroscopy. The crystallographic phases of sintered particles were determined by X-ray diffraction. The crystallographic phases of sintered particles were determined by X-ray diffraction. [Display omitted] • Multifunctional flexible CF. • Low cost and effective Ag deposition onto CF. • CF/Ag fabrics with multispectral EMI SE of 50 dB. • The tensile stress of CF increased by 4.6 times. • Capacitive properties of CF/Ag fabrics. [ABSTRACT FROM AUTHOR]

Morphology and development of surface damage of alumina-based materials, resulting from cavitation erosion is studied in this paper. Two series of samples were prepared: samples without fibers and those with the addition of 2 wt % of ceramic fibers. The form of surface damage is considered to be the information carrier for the analysis of the resistance of materials to cavitation and the quality of this information is determined. The surface of the samples was monitored in defined time intervals in order to prepare the digitized image suitable for further analysis using image analysis software. The principal component analysis was applied to examine the appearance of certain morphological characteristics depending on the behavior of the material during cavitation erosion. It was concluded that the addition of ceramic fibers gained in importance after a long time of cavitation erosion, while during a starting period of time the difference in the morphology of the damage is not very observable. • Cavitation exposed surface analysis was pared with the mass loss measurement. • Reinforced ceramic matrix composite is more resistant to cavitation. • The addition of ceramic fiber proved to exhibit less changes in the surface damage with time. • The most informative parameters are those characterizing the overall size of individual surface damages. [ABSTRACT FROM AUTHOR]

Lab-made biosilica (SiO2) nanoparticles were obtained from waste biomass (rice husks) and used as eco-friendly fillers in the production of nickel matrix composite films via the co-electrodeposition technique. The produced biosilica nanoparticles were characterized using XRD, FTIR, and FE-SEM/EDS. Amorphous nano-sized biosilica particles with a high SiO2 content were obtained. Various current regimes of electrodeposition, such as direct current (DC), pulsating current (PC), and reversing current (RC) regimes, were applied for the fabrication of Ni and Ni/SiO2 films from a sulfamate electrolyte. Ni films electrodeposited with or without 1.0 wt.% biosilica nanoparticles in the electrolyte were characterized using FE-SEM/EDS (morphology/elemental analyses, roundness), AFM (roughness), Vickers microindentation (microhardness), and sheet resistance. Due to the incorporation of SiO2 nanoparticles, the Ni/SiO2 films were coarser than those obtained from the pure sulfamate electrolyte. The addition of SiO2 to the sulfamate electrolyte also caused an increase in the roughness and electrical conductivity of the Ni films. The surface roughness values of the Ni/SiO2 films were approximately 44.0%, 48.8%, and 68.3% larger than those obtained for the pure Ni films produced using the DC, PC, and RC regimes, respectively. The microhardness of the Ni and Ni/SiO2 films was assessed using the Chen-Gao (C-G) composite hardness model, and it was shown that the obtained Ni/SiO2 films had a higher hardness than the pure Ni films. Depending on the applied electrodeposition regime, the hardness of the Ni films increased from 29.1% for the Ni/SiO2 films obtained using the PC regime to 95.5% for those obtained using the RC regime, reaching the maximal value of 6.880 GPa for the Ni/SiO2 films produced using the RC regime. [ABSTRACT FROM AUTHOR]

Composites are materials that reach many users and therefore, it is necessary to correlate the properties of every component on the behaviour of the material. Alumina is used as reinforcement with the aim of improving hardness. It was proven that the hardness depends on the crystal structure of the reinforcement. As the hardness is related to cavitation resistance, the influence of different reinforcements on the composite cavitation resistance was studied. Alumina and iron(III) oxide doped alumina particles were prepared by the sol-gel technique, starting from soluble salts of both elements. The gels were calcined at three different temperatures: 700, 800 and 900 °C. Poly(methyl methacrylate), PMMA, was used as the polymer matrix reinforced with alumina particles. The reinforcement content of all the samples was 3 wt %. Cavitation erosion of the samples was measured using a standard ultrasonic vibratory setup with a stationary sample. The cavitation resistance of the samples was studied using the classical mass loss method and the surface defects resulting from cavitation were analyzed. The morphologies of the defects after 1 h of cavitation erosion were examined by field emission scanning electron microscopy (FE-SEM). The images were characterized using the image analysis procedure. The results showed that the alumina crystal structure resulting at different calcination temperatures influences the defect morphology, cavitation resistance and the hardness of the composites. • Correlation of the crystal structure of the reinforcement and behaviour of the surface of the composite under cavitation. • The cavitation erosion and surface degradation are studied. • Surface roughness, damage resulting from surface erosion were studied via different image analysis tools. • Particles were calcined at three different temperatures: 700, 800 and 900 °C. [ABSTRACT FROM AUTHOR]

This paper presents sustainable technology for environmentally friendly composite production. Biobased unsaturated polyester resin (b-UPR), synthesized from waste polyethylene terephthalate (PET) glycosylate and renewable origin maleic anhydride (MAnh) and propylene glycol (PG), was reinforced with unmodified and vinyl-modified biosilica nanoparticles obtained from rice husk. The structural and morphological properties of the obtained particles, b-UPR, as well as composites, were characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The study of the influence of biosilica modification on the mechanical properties of composites was supported by hardness modeling. Improvement of the tensile strength of the b-UPR-based composite at 2.5 wt.% addition of biosilica modified with vinyl silane, named "b-UPR/SiO2-V" composite, has been achieved with 88% increase. The thermal aging process applied to the b-UPR/SiO2-V composite, which simulates use over the product's lifetime, leads to the deterioration of composites that were used as fillers in commercial unsaturated polyester resin (c-UPR). The grinded artificially aged b-UPR composites were used as filler in c-UPR for the production of a table top layer with outstanding mechanical properties, i.e., impact resistance and microhardness, as well as fire resistance rated in the V-0 category according to the UL-94 test. Developing sustainable composites that are chemically synthesized from renewable sources is important from the aspect of preserving the environment and existing resources as well as the extending their life cycle. [ABSTRACT FROM AUTHOR]

Quantitative assessment of the adhesion behavior between the composite film having UV cured Bis-GMA (Bisphenol A glycidylmethacrylate)/TEGDMA (triethylene glycol dimethacrylate) as matrix and the aluminum oxide based particles as a reinforcement on metallic surface was done using the microhardness testing method and compared to the contact angle. Composites are made with 1 wt %, 3 wt %, 5 wt % and 10 wt % of alumina based fillers. Films were subjected to the cavitation in order to evaluate the erosion resistance of the composite film on the metal. It is proved that the adhesion is improved with addition of the fillers while the cavitation resistance is improved up to 5 wt % of fillers. [ABSTRACT FROM AUTHOR]

Polymer matrix composite materials have found application in dentistry because of good mechanical properties, aesthetic, easy processing, and possibilities of the repair. Acrylates are materials used to make and repair dentures. Reinforcements in the form of short glass or polymer fibers are added to improve the mechanical properties of dental polymers. In this study, the processing of composite material with a polymer matrix from commercial auto‐polymerized acrylate Simgal, with reinforcement in the form of short poly(ethylene terephthalate) (PET) fibers was examined. Samples were processed in three series: pure Simgal, Simgal/PET 1 wt% and Simgal/PET 3 wt%. The influence of the reinforcement in the form of short PET fibers on the mechanical properties of composite materials was investigated. Strength and hardness were tested by impact testing and Vickers microhardness, and it was shown that there is an increase in absorbed energy and hardness. The modulus was reduced by the addition of PET fibers and by increasing the amount of fibers in the composite. The increase in the amount of PET fibers also resulted in a smaller loss of surface mass of the samples compared to the pure matrix by 63% and 93%, respectively. Cavitation test revealed better cavitation resistance of composites than the pure acrylate. [ABSTRACT FROM AUTHOR]

The goal of this study was to investigate the effect of the structure of Mn-Al layered double hydroxide (LDH) on the adhesion behavior of composite adhesives on two Al alloys (L3005 and L8079). The composite adhesives were made out of the UV-curing Bisphenol A glycidylmethacrylate/triethylene glycol dimethacrylate (BT) as polymer matrix and the addition of 1, 3, and 5 wt. % of Mn-Al LDH as adhesion enhancers. Adhesion was evaluated by using the micro Vickers hardness testing procedure. The wetting angle of composite adhesives to the Al substrates was measured and compared to the adhesion parameter b obtained from the microhardness tests. The highest increase in adhesion was observed for BT with 5 wt. % of Mn-Al LDH on L3005 substrate, which was more than 15 times higher than the adhesion for the neat BT. The morphological segregation of composite adhesives after the contact with Al substrates was examined by optical microscopy and a higher compatibility of Mn-Al LDH particles with L3005 substrate was found. The methods used for the adhesion properties assessment suggested that the Mn-Al LDH was the best adhesion enhancer of the BT matrix for L3005 substrate containing a higher content of Mn and surface hydroxyl groups. [ABSTRACT FROM AUTHOR]

PMMA poly(methyl methacrylate) has a large spectrum of uses as bone cements, in dentistry as denture base materials and other industrial applications. One of the main drawbacks of these materials is the residual monomer that is proven allergen and irritant. It was shown that addition of dimethyl itaconate (DMI) to the PMMA denture base systems decrease the quantity of residual monomer but, also deteriorate mechanical properties. The addition of alumina fillers in the PMMA/DMI produced composite materials results in improved mechanical properties compared with pure PMMA and additionally reduces the level of residual monomer in the composition. POLYM. COMPOS., 40:1691–1701, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Highlights • New methods proposed in investigating of compatibilization effect. • Monitoring of polymer blend morphology, while designing and controlling the mechanical properties. • Improving of mechanical properties by compatibilization of polymer blends. Abstract Poly(ethylene- co -vinyl acetate) (EVA) and poly(methyl methacrylate) (PMMA) are two incompatible polymers. Compatibilization of EVA/PMMA polymer blends with EVA- g -PMMA decreased the pore diameter and improved the mechanical properties. Image analysis of SEM micrographs enabled statistical analysis of the porosity parameters, including data about their positions. Positioning of the pores on the image was achieved by implementation of Voronoi diagrams and Delaunay triangulation by Python libraries. Hausdorff dimension (DH f) analysis showed improved complexity of the material network obtained by compatibilization. The coordinates of pore contours were processed by the Ramer–Douglas–Peucker algorithm (RDP) to establish the models by the finite element method (FEM). This process is iterative and enables a parametric study of the problem so that the type of pore geometry responsible for the observed mechanical behavior could be revealed. The FEM revealed the regions of the material that bear the load and enabled the extraction of parts of the material that diminish the porosity but do not participate in load carrying. A parametric study showed a decrease of 22% in the maximal shear stress when the porosity increased 10%, suggesting the importance of bulging of the material that played the role in decreasing the porosity of non-bearing material. A procedure for selecting the model with a regular pore shape and distribution based on the actual (irregular) porous microstructure is proposed. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate quantitative assessment of the adhesion behavior of composite films onto a metallic surface. The composite films had UV cured Bis-GMA (Bisphenol A glycidylmethacrylate)/TEGDMA (triethylene glycol dimethacrylate) as matrix and ferrous oxide doped alumina (Al 2 O 3 Fe) particles with two surface modifications, (3-methacryloxypropyltrimethoxysilane) (MEMO) and the vinyltris(2-methoxyethoxy)silane (VTMOEO), as reinforcement. Composites were made with 0.5, 1.5 and 3 wt% of alumina particles. Adhesion was evaluated using the micro hardness testing method. The contact angle was measured and compared to the adhesive parameter from micro hardness measurements. The form of the indent on the surface of the composite film was analyzed in order to correlate the indent morphology to the adhesion quality. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the influence of polyhedral oligomeric silsesquioxane (POSS) structure on the adhesion behaviour of composite films onto a metallic surface. The composite films consisted of UV cured bisphenol A glycidylmethacrylate/triethylene glycol dimethacrylate (Bis-GMA/TEGDMA) as matrix and reactive POSS structures as adhesion enhancers. Composites were made with 1, 3 and 5 wt % of POSS. Adhesion was evaluated using the micro Vickers hardness testing method. The contact angle of composite films to a brass substrate was measured and compared to the adhesion parameter obtained from microhardness measurements. Optical microscopy indicated morphological segregation in the hybrid films suggesting the compatibility extent between the matrix and each particle. The shape and size of the indent were analyzed and correlated with adhesion quality. The methods used for the estimation of adhesion strength and quality clearly indicated that the highest adhesion enhancement of the Bis-GMA/TEGDMA matrix was POSS reagent containing both polar (hydroxyl) and nonpolar (unsaturated aliphatic - allyl) side groups. [ABSTRACT FROM AUTHOR]