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In this paper, a novel approach to evaluate the neutron shielding performance of multiphase neutron absorber reinforced aluminum matrix composites was proposed through the establishment of a direct relationship between equivalent B areal density (EBAD) of the composite and its thermal neutron shielding coefficient. It was found when the EBAD of the composite was 0.1105 g/cm 2 , the thermal neutron shielding coefficient will achieve 99%. Based on this proposed approach, (1% Gd+15% B 4 C)/6061Al composite plates were successfully fabricated using vacuum hot pressing method followed hot rolling. The results showed that when the EBAD of the composite was 0.1871 g/cm 2 , the thermal neutron shielding coefficient was above 99.9%, which was consistent with the theoretical calculation. The 5 mm-thick composite plate also had a good shielding effect on the Am-Be neutron source. Meanwhile the composite possessed a 380 MPa tensile strength as well as an elongation of 5% after hot rolling. In all, the (Gd + B 4 C)/6061Al composite designed in this paper showed better comprehensive performance compared with the literature's. The work of this paper has a great guiding significance for the design and preparation of neutron absorbing composites with high thermal neutron shielding performance as well as high strength and plasticity.

Using a facile strategy to fabricate multifunctional cotton fabrics with superhydrophobicity, conductivity and antibacterial activity is an important and urgent issue in the development of natural fabrics. Herein, a new type of cotton fabric, denoted as Cot@PDA/Ag/NDM, has been fabricated utilizing mussel-inspired polydopamine (PDA) chemistry, followed by electroless Ag plating and n-dodecyl mercaptan (NDM) self-assembly. The influence of dopamine (DA) and AgNO3 concentration on the surface morphology and conductivity, as well as NDM treatment time on the surface wettability of the fabric is systematically investigated. Cot@PDA/Ag/NDM not only exhibits superhydrophobicity with water contact angle of 155.9 ± 1°, but also possesses excellent self-cleaning and antifouling properties. In addition, the fabric has a highly conductive surface with sheet resistance as low as 10.2 Ω cm, and shows outstanding mechanical properties and antibacterial activity against Escherichia coli and Staphylococcus aureus.

A novel and effective method was proposed for grafting carbon nanotubes (CNTs) with amino groups onto the surface of carbon fibers (CFs) by using one-pot aryl diazonium reaction in mild, eco-friendly conditions. Based on the diazonium reaction, CNTs were grafted with phenyl amino groups, and then functionalized CNTs (CNT-NH2 ) were modified onto the fiber surface to enhance fiber surface roughness and wettability , which could potentially increase interfacial strength of composites. Homogeneous multi-scale structures with different concentrations of CNTs were achieved. Interfacial properties of hybrid composites were closely dependent on the grafting density. The resulting hierarchical reinforcements improved composites interfacial strength significantly by the enhanced mechanical interlocking and the formed chemical bonding at the interface.

This study was conducted to obtain a type of aluminum matrix composites exhibiting a good strength and certain ductility at high temperature. The 25 vol% TiO2-75 vol%2024 Al systems were selected to fabricate the (Al3Ti+Al2O3)/2024 Al composites with residual ∼32 vol% Al matrix through powder metallurgy. The (Al3Ti+Al2O3)/2024 Al exhibits a good strength and certain ductility at high temperature as in the design. The microstructure of (Al3Ti+Al2O3)/2024 Al composites was investigated. It was discovered that the in-situ Al3Ti reinforcement was in coarse block-shaped particles of approximately 6.9 μm in size and the Al-Al3Ti interface was clean. The Al2O3 particles were in the nano-scale and distributed in the Al matrix in a cluster form. The high temperature compression testing of the composites was conducted at the temperatures of 573 K, 623 K, 673 K, 723 K and 773 K with the strain rate of 10−3 ∼ 0.42 s−1. The results demonstrated that the composites exhibited higher strength at the same high temperature than the other Al matrix composites with a similar volume fraction. The massive Al3Ti and Al2O3 phases played a load bearing role at high temperatures. The residual ∼32 vol% Al matrix led the composites to acquire certain ductility.

A novel boron carbide and gadolinium particles reinforced Al neutron shielding composite (1% Gd+15% B4C)/6061Al was successfully fabricated by vacuum hot pressing method, and its microstructure and tensile properties during hot rolling were studied. The results indicated that, the main Gd-containing phase during hot rolling was Al5Gd3O12, and the size decreased with the increase of the derformation amount. The results of thermodynamic calculations confirmed the possibility of the formation of Gd-containing phases in the preparation process. The main defects of the Gd-containing phases were stacking faults. During the hot rolling process, the mechanical properties of the (1% Gd+15% B4C)/6061Al composite were better than the 15% B4C/6061Al composite. The increase in strength came from the strengthening effect of the Gd-containing phases, which was consistent with the theoretical calculations. Stacking faults in the Gd-containing phases allowed dislocations to slip through, thereby improving the plasticity of the composite.

The ternary roles of polyethyleneimine (PEI) as a polymer matirx, a reducing agent and a surface modifier have been presented to fabricate graphene oxide (GO) reinforced polymer nanocomposite films. GO is modified with PEI-glycerol diglycidyl ether (GDE) cross-linking networks in aqueous solution and in situ reduced by PEI simultaneously. Synergistic reinforcement of mechanical interlocking and hydrogen bonding leads to dramatic increases in tensile strength and Young’s modulus by 98.3% and 87% respectively, at 7.5 wt% GO loading of PEI. The partial reduced GO sheets serve as moisture barriers for water-soluble PEI, and the nanocomposite films are shown to be structurally robust humidity sensors over the relative humidity (RH) range of 40–90%.

Octamaleamic acid-polyhedral oligomeric silsesquioxanes (OMA-POSS) were chemically modified onto the surface of carbon fibers (CFs) by a facile and high efficient two-step method. CF was grafted with hydroxyl groups via aryl diazonium reaction, and then covalently functionalized with OMA-POSS. The grafting density could be tuned through the concentration of OMA-POSS. Fiber surface structures were characterized by confirming the covalent bonding nature between OMA-POSS and CF. OMA-POSS was scattered on CF surface uniformly, and fiber polarity and roughness increased with the increased grafting density of OMA-POSS. Interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the modified CFs composites enhanced as the grafting density grew, which could be ascribed to OMA-POSS interface with providing different degrees of chemical bonding and mechanical interlocking. Moreover, the hydrothermal aging resistance of composites is highly dependent on the amounts of the introduced OMA-POSS. The storage modulus and the glass transition temperature could increase by 8 GPa and 14 °C based on dynamic mechanical analysis testing. In addition, the interfacial reinforcing mechanisms have been also analyzed, and surface modification maintained fiber tensile strength.

A novel amine-based functionalization method was developed to improve the interfacial adhesion between TiO 2 NWs and CFs in supercritical water. The microstructure, morphology and mechanical properties of CFs were investigated. It was found that introducing hexamethylenetetramine (HMTA) dendrimers and branched polyethyleneimine (PEI) on CF could increase significantly the adhesion strength between CF and TiO 2 NWs and their interfacial shear strength with epoxy resin, and the order is CF-PEI-TiO 2 NWs > CF-HMTA-TiO 2 NWs > CF-COOH-TiO 2 NWs > CF-TiO 2 NW. Meanwhile, the reinforcing mechanisms and interfacial failure modes have also been discussed. We believe that these effective methods may provide theoretical foundation for the preparation of high performance composite materials.

Controlling interfacial microstructure and interactions between carbon fiber (CF) and matrix is of crucial importance for the fabrication of advanced polymer composites. In this paper, a hierarchical reinforcement (CF-g-SiO2) was prepared through directly grafting 3-aminopropyltriethoxysilane (APS) functionalized silica nanoparticles (SiO2-APS) onto CF surface by the covalent linkage for the first time. SiO2-APS nanoparticles distributed onto the fiber surface uniformly, which could increase surface polarity and roughness obviously. CF-g-SiO2 exhibited a low contact angle and high surface free energy, and thus enhanced the wettability between CF and matrix greatly. Simultaneous increases of interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of CF-g-SiO2 composites were achieved, increasing 53.27% in ILSS and 40.92% in IFSS compared with those of untreated composites. These enhancements can be attributed to the existent of SiO2-APS interface with providing sufficient chemical bonding and strong mechanical interlocking between the fiber and matrix. Moreover, impact resistance of CF-g-SiO2 composites was enhanced with increasing the amplitude of 34.95%. In addition, the introduction of Si-O-Si bonds at the interface by SiO2-APS grafting leads to the remarkable enhancement of the hydrothermal aging resistance.

Introducing nano-scale reinforcements into carbon fiber (CF)-matrix interface is a useful method to enhance interfacial strength of composites. In this work, we demonstrated a facile and high efficient strategy of preparing octa(aminophenyl) polyhedral oligomeric silsesquioxane (OapPOSS)/CF hierarchical reinforcements (CF-g-POSS) by directly grafting OapPOSS on CFs by covalent bonding. OapPOSS distributed on fiber surfaces uniformly, and enhanced surface polarity as well as roughness significantly. CF-g-POSS exhibited a low contact angle and high surface free energy, which helped to change the wettability between CF and the matrix. Simultaneous enhancements of interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of CF-g-POSS/methylphenylsilicone resin (MPSR) composites were achieved, increasing 47.83% in IFSS and 59.04% in ILSS compared to those of untreated composites. These enhancements could be attributed to OapPOSS interface with providing sufficient covalent bonding and strong mechanical interlocking. Additionally, anti-hydrothermal aging behaviors were also increased obviously owing to the introduction of Si O Si bonds at the interface.

It is widely accepted that the interfacial properties of carbon fiber (CF) reinforced composites tend to be weak due to the poor wettability and chemically inert surface of CF, which greatly limits the reinforcement effect of CF in composites. Here, size-controllable graphene oxide sheets (GO) were grafted on CF using Poly(oxypropylene) Diamines (D 400 ) as the bridging agent to improve the interfacial properties of CF composites. It was found that the size and content of active functional groups on GO played important roles in controlling the surface morphology of GO grafted CF. Moreover, the interfacial shear strength (IFSS) of the middle sized GO sheets grafted CF/epoxy composites reached a maximum value of 82.2 MPa, with an enhancement of 75.6% compared with untreated CF. That is to say, the strong mechanical interlocking between CF and epoxy resin and the improved wettability of resin on CF surface were responsible for the enhancement of IFSS. Instead of decaying of fiber tensile strength after treatment, the tensile strength of GO grafted CF increased from 4.73 GPa to 5.02 GPa. The reason for the enhancement may be due to that GO bridged the surface defects on CF. This hierarchical reinforcement was believed to have widely potential applications in high performance polymer matrix composites.

We report on a green method of using poly(oxypropylene) diamines (D400) as coupling and curing agent to functionalize carbon fiber in water. We propose to enhance the interfacial properties of carbon fiber composites, together with the tensile strength of carbon fibers. The microstructure and mechanical properties of carbon fibers before and after modification are investigated. The results show that D400 do not change the surface morphology, but significantly increase the polarity, wettability and roughness of the carbon fiber surface. The interfacial shear strength (IFSS) of modified carbon fiber/epoxy composite and the tensile strength of carbon fibers increase by 79.1% and 8.2%, respectively. It is believed that D400 can effectively improve the interfacial adhesion of the composites by improving resin wettability, increasing chemical bonding and mechanical interlocking. This green and simple method can have applications in continuous production of high-performance carbon fiber composites.

Effects of silane and silica enrichment of carbon fibers (CFs) on interfacial properties of methylphenylsilicone resin (MPSR) composites were investigated. CFs were oxidized, grafted with 3-aminopropyltriethoxysilane (APS) and then modified with silica nanoparticles prepared by the sol-gel polymerization of tetraethoxysilane (TEOS). Chemical structures of CFs were characterized by confirming the successful grafting. Scanning electron microscopy (SEM) showed a uniform distribution of silica nanoparticles on the CFs surface. The interlaminar shear strength (ILSS) and impact toughness of silanized CF (CF-Siloxane) composites were 12.05% and 7.46% higher than those of untreated composites. However, ILSS and impact toughness of the hybrid fiber (CF/Si) composites obtained from the hydrolysis of different concentrations TEOS improved significantly, especially for grafting silica enrichment with the TEOS concentration of 0.05 mol/L (CF/Si0.05), increasing 45.64% in ILSS and 29.59% in impact properties. Moreover, the hydrothermal aging resistance was also improved greatly. Meanwhile, functionalization processes did not decrease fiber tensile strength.

A new hierarchical reinforcement was fabricated by growing ZnO nanowires (NWs) onto poly( p -phenylene benzobisoxazole) (PBO) fibers using a mild hydrothermal method, which served as a platform for the polyhedral oligomeric silsesquioxanes (POSS) grafting, using 3-aminopropyltrimethoxysilane (APTMS) as a bridging agent. Scanning electron microscopy (SEM) was employed to characterize the surface morphologies of PBO fibers and the de-bonding surface morphologies of their composites. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the chemical bonding nature between ZnO NWs and APTMS, as well as between APTMS and POSS. The reinforcement offered a 83.4% enhancement in the interfacial shear strength (IFSS) without degrading the base fiber. Moreover, the possible interfacial property enhancing reasons were explored. The hydrothermal aging resistance of PBO/epoxy composites was also greatly improved.

Poly( p -phenylene benzobisoxazole) (PBO) fibers are ideal candidates for cables in tether application and reinforcements in advanced composites. Upon exposure to atomic oxygen (AO) in low earth orbit (LEO), PBO fibers are severely eroded. In this study, the AO erosion behaviors of PBO fibers and their composite were investigated in simulated AO environment, based on the evaluation of microstructure, surface chemistry, thermal stability and mechanical properties. Surface morphologies and crystalline structure confirmed that PBO fibers were significantly eroded after AO irradiation. X-ray photoelectron spectroscopy (XPS) showed that the relative content of C C decreases with the increase of AO irradiation time, suggesting a chain scission of PBO fibers. After 8 h AO exposure, the tensile strength of PBO fibers was decreased by 31.6%, and the onset decomposition temperature was reduced by 30.8 °C. Monofilament pull-out tests showed that the interfacial shear strength (IFSS) of PBO/epoxy composite was as low as 61.3% that of pristine composite due to the interface damage caused by AO penetration.

The interface between carbon fibers (CFs) and matrix resin makes a critical contribution to bulk performance of composites. In order to enhance interfacial properties and anti-hydrothermal aging behaviors of methyl phenyl silicone resin (MPSR) composites, octamaleamic acid-polyhedral oligomeric silsesquioxanes (POSS-acid) were directly grafted onto CFs surface by chemical bonding for the first time. Surface chemical groups and morphologies of CFs before and after POSS-acid grafting were systematically characterized. Scanning electron microscopy and atomic force microscopy images showed a uniform distribution of POSS-acid on the fiber surface and the improved surface roughness. POSS-acid cages grafting could improve obviously the fiber polarity, wettability, and free energy by dynamic contact angle analysis testing. The interlaminar shear strength (ILSS) of MPSR composites reinforced with the POSS-acid-modified CFs (CF-POSS) was 45.01 ± 1.69 MPa, which increased by 52.73 % compared to that of MPSR composites reinforced with untreated CFs (29.47 ± 0.94 MPa). And, impact strength of CF-POSS composites (77.69 ± 2.83 kJ m−2) was increased by 32.89 % compared to that of untreated CF composites (58.46 ± 1.91 kJ m−2). Moreover, ILSS of CF-POSS composites after hydrothermal aging treatment was 40.89 ± 1.51 MPa with a decrease of just 9.15 % compared to that of untreated CF composites (20.52 ± 0.65 MPa) with an obvious decrease of 30.37 %. Meanwhile, POSS-acid functionalization did not decrease fiber tensile strength. Based on our design starting from simple chemistry and inexpensive materials, such hierarchical reinforcements with improved interfacial strength and anti-hydrothermal aging behaviors have great potential in advance polymer matrix composites.

Octaglycidyl polyhedral oligomeric silsesquioxane (gly-POSS) was successfully grafted on carbon fibers (CFs) surface to enhance interfacial properties and impact toughness of CFs reinforced methylphenylsilicone resin (MPSR) composites. After gly-POSS modification, POSS grafted CF (CF-POSS) with many epoxy functional groups was modified with tetraethylenepentamine (TEPA) to further enhance the interfacial strength. Atomic force microscopy (AFM) images showed that POSS and TEPA were grafted onto CFs surface uniformly and the surface roughness enhanced obviously. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the chemical bonding nature between CFs and POSS, as well as between POSS and TEPA. POSS and TEPA modification could increase the fiber polarity, wettability and surface energy significantly. The interlaminar shear strength (ILSS) and impact toughness of composites showed a dramatic improvement, especially for grafting with POSS and further with TEPA (CF-POSS-TEPA). Additionally, the reinforcing and toughening mechanisms were also analyzed. Meanwhile, single fiber tensile strength (TS) had no decrease after modification.

The surface topographies of carbon fibers treated by sizing agents with different graphene oxide (GO) content were investigated by scanning electron microscopy. The surface elements compositions of carbon fibers were determined by X-ray photoelectron spectrometer. The interfacial properties of composites were studied by interfacial shear strength. The thermo-mechanical properties of two typical specimens (CF-G0 and CF-G1 composites) were investigated by dynamic mechanical thermal analysis. The results showed the introduction of GO sheets on carbon fibers surfaces effectively improved the mechanical properties of carbon fibers/epoxy composites. POLYM. COMPOS., 38:2425–2432, 2017. © 2016 Society of Plastics Engineers

The grafting of trisilanolphenyl-polyhedral oligomeric silsesquioxanes (trisilanolphenyl-POSS) onto carbon fibers (CFs) was achieved using toluene-2,4-diisocyanate (TDI) as the bridging agent. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the successful modification of trisilanolphenyl-POSS. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images showed that trisilanolphenyl-POSS nanoparticles were grafted uniformly onto the surface of CFs and the surface roughness increased significantly. The results of dynamic contact angle (DCA) measurements demonstrated an improvement in the surface energy and wettability that related to the increased polarity of the obtained hybrid fibers (CF-g-POSS). The effects of trisilanolphenyl-POSS grafting on the interfacial, impact, and heat-resistant properties of methylphenylsilicone resin (MPSR) composites were also studied. The interlaminar shear strength (ILSS) and impact resistance of methylphenylsilicone resin (MPSR) composites after POSS modification were improved significantly with increasing amplitudes of 41.91% and 28.65%, respectively. Moreover, the interfacial reinforcing and toughening mechanisms of composites have also been discussed. In addition, the thermal oxygen aging experiments indicated a remarkable improvement in the heat oxidation resistance by the introduction of trisilanolphenyl-POSS in the interphase. Meanwhile, the grafting processes do not decrease fiber tensile strength (TS).

We proposed an easy and effective method to prepare multiwall carbon nanotubes (CNTs) modified sizing agent suited for carbon fibers (CFs) reinforced methylphenylsilicone resin (MPSR) composites. In order to improve the dispersion of CNTs in sizing agent and interfacial adhesion between CNTs and MPSR, CNTs were covalently functionalized with 3-aminopropyltriethoxysilane (APS) and the silanized carbon nanotube (CNT-APS) was introduced into the interface by sizing process as well. The CFs with and without sizing treatment reinforced MPSR composites were prepared by a compression molding method. Scanning electron microscopy (SEM) showed a uniform distribution of CNTs on the fiber surface and the enhancement of the surface roughness. Compared with untreated CFs composites, the interlaminar shear strength (ILSS) and impact toughness of CFs after sizing treatment containing 0.1 wt.% CNTs composites increased slightly owing to the serious agglomeration of excessive CNTs. However, the sized fibers modified with 0.5 wt.% CNT-APS composites revealed a significant increase 46.52% in ILSS and 31.12% in impact properties. Moreover, the reinforcing and toughening mechanisms were also discussed. In addition, the tensile strength (TS) of sized CFs showed a slightly increase in comparison with that of untreated CFs. Keywords: Carbon fiber, Sizing agent, Carbon nanotube, Composite material, Interfacial property, Impact performance

Using molten urea as the solvent, carbon fibers were functionalized with carboxylic acid groups via aryl diazonium reaction in 15 min to improve their interfacial bonding with epoxy resin. The surface functionalization was quantified by X-ray photoelectron spectroscopy, which showed that the relative surface coverage of carboxylic acid groups increased from an initial percentage of 3.17–10.41%. Mechanical property test results indicated that the aryl diazonium reaction in this paper could improve the interfacial shear strength by 66%. Meanwhile, the technique did not adopt any pre-oxidation step to produce functional groups prior to grafting and was shown to maintain the tensile strength of the fibers. This methodology provided a rapid, facile and economically viable route to produce covalently functionalized carbon fibers in large quantities with an eco-friendly method.

Metal nanoparticles are commonly used for surface modification in fiber reinforced polymer composites because of their large specific surface area and electronic, magnetic and other related properties. In this study, morphology-controllable silver nanoparticles (Ag NPs) were deposited on a carbon fiber surface via a facile and green electro-chemical deposition method in the presence of poly(vinylpyrrolidone) (PVP). It was found that the presence of PVP and its molar ratio (in terms of repeating unit) relative to silver nitrate both played important roles in determining the geometric shape and size of the Ag NPs. Interestingly, electro-chemical deposition of Ag NPs improved both the tensile strength of the carbon single fiber and the interfacial property of the carbon fiber/epoxy composite by as much as 57.2% and 27.2%, respectively. Moreover, the Ag NPs-loaded carbon fibers exhibited superior electrical conductivity, which was a 2-fold enhancement as compared with that of the virgin carbon fibers. It meant that the Ag NPs-loaded carbon fibers could be used as ideal reinforcement materials for advanced aerospace systems.

The one-step generation of nano-silica (SiO2) on graphene oxide (GO) surface via using diethylenetriamine (DETA) and ammonium hydroxide (NH4OH) base catalysts was respectively designed to improve the dispersion and interfacial interaction between GO and epoxy resin. The structures and morphologies of GO, GO-SiO2(i) and GO-SiO2(ii) sheets were tested by FT-IR, XRD, XPS, TG, SEM and TEM. Epoxy composites containing GO, SiO2, GO-SiO2(i) and GO-SiO2(ii) with 0.1 wt% loadings were prepared and systemically investigated. It was indicated that the GO-SiO2/epoxy composites displayed higher tensile, flexural and impact strength and modulus than that of GO composites. For epoxy composites containing 0.1 wt% GO-SiO2(i) and GO-SiO2(ii), the flexural strength increased by 34.35% and 25.08% compared to that of GO composites, respectively. Furthermore, the reinforcing mechanisms have been also illuminated. This work is expected to offer a potential scale application of high-performance nanocomposites.

The gradient modulus intermediate layer between CF and epoxy by designing double “rigid-flexible” structure using CNTs and polyamide (PA) on the CF surface was firstly established, and the effects of modulus intermediate layer on interfacial and mechanical properties of CF composites were investigated. The constructing of double “rigid-flexible” structure on the CF surface can greatly increase the polar functional groups, roughness and wettability of the CF surface as well as the thickness of intermediate layer, which could balance the modulus of fiber and resin to achieve the best matching. The interfacial shear strength (IFSS), interlaminar shear strength (ILSS), flexural strength, and impact strength of CF composites increased by 75.6%, 44.1%, 41.3%, and 34.6%, respectively. In addition, the interfacial failure behaviors and strengthening mechanisms of composites have been studied. This novel design and method built a multistage gradient modulus intermediate layer of composite with strong physicochemical interaction and good wettability, which has greatly potential for high-performance composite.

The multi-scale reinforcement and interfacial strengthening on carbon fiber (CF)-reinforced methylphenylsilicone resin (MPSR) composites by adding silica-coated multi-walled carbon nanotubes (SiO2-CNTs) were investigated. SiO2-CNT has been successfully prepared via the hydrolysis of tetraethoxysilane in the presence of acid-oxidized multi-walled carbon nanotubes. Transmission electron microscopy, X-ray diffraction, and Fourier Transform infrared spectroscopy were carried out to examine the functional groups and structures of CNTs. Then, SiO2-CNT was incorporated into MPSR matrix to prepare CF/MPSR-based composites by the compression molding method. The effects of the introduced SiO2-CNT on the interfacial, impact, and heat-resistant properties of CF/MPSR composites were evaluated by short-beam bend method, impact test, and thermal oxygen aging experiments, respectively. Experimental results revealed that the CF/MPSR composites reinforced with 0.5 wt% SiO2-CNT showed a significant increase 34.53% i...

Besides chemical bonding, surface wettability and roughness of carbon fibers (CFs) also play key roles in improving interfacial adhesion of CFs composites. In this study, the roles of surface wettability and roughness of CFs in interfacial enhancement of methylphenylsilicone resin composites were systematically studied. p-Phenylene trimethoxyaminosilane (PTMAS) was chemically grafted onto CFs to increase surface polarity and wettability. Furthermore, by bridging PTMAS, the bigger surface roughness of fibers was obtained after following epoxycyclohexyllsobutyl-polyhedral oligomeric silsesquioxanes (POSS) grafting. PTMAS grafting (CF–PTMAS) had higher wettability and surface energy than that of the grafting with PTMAS and further with POSS (CF–PTMAS–POSS). However, surface roughness of CF–PTMAS was lower than that of CF–PTMAS–POSS. Interfacial shear strength and interlaminar shear strength showed great enhancements, especially for CF–PTMAS–POSS composites, indicating that surface roughness played more important role than the wettability for interface improvement. Additionally, antihydrothermal aging behaviors were also improved obviously. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

A facile and rapid come close to the manufacture of advanced epoxy nanocomposites by grafting of nano-silicon dioxide (nano-SiO2) onto the graphene oxide (GO) through thiol-ene click reaction was reported. The correlations between surface modification, morphology, dispersion/exfoliation, interfacial interaction of sheets and the corresponding mechanical properties of the composites were methodically explored. It appeared that nano-SiO2 have been grafted onto GO via covalent bonding successfully, which effectively improved the interface compatibility and dispersion in epoxy matrix. The reinforcing mechanisms has been also elaborated. It is demonstrated that the tensile strength and elastic modulus for filler with 0.1 wt% GO-SiO2/epoxy composites increased by 32.18% and 22.86% compared to neat epoxy, respectively. It is believed that the simplistic and effectual method may provide a novel and promising strengthen design strategy for next‐generation advanced nanocomposite structures.