Solution Blending Method Research Articles

Influences of preparation process on electrical conductivity and thermal expansion coefficient of epoxy/graphene nanocomposites

In this study, graphene (1 wt% to 5 wt%) is added into epoxy to prepare epoxy/graphene composites by the solution blending method. The process includes the ultrasonication mixing, the mechanical mixing and the isothermal curing. The influences of ultrasonication and curing process on the composite properties are investigated. The microstructure is characterized by AFM (atomic force microscope), SEM (scanning electron microscope), TEM (tunnel electron microscope) and XRD (x-ray diffraction). Based on the experiments, it is concluded that in the ultrasonication mixing, excessive power or operation time may destroy the graphene structure, while insufficient power or operation time may result the aggregation of graphene, both states will lead to the lower electrical conductivity of the composites. Isothermal curing is carried out by a two-step process. By adjusting the parameters, a new fabrication technique is developed. The maximum electrical conductivity of epoxy/graphene composites reaches 2.5 × 10−5 S m−1, which is of great potential in the electrical industry.

Blending Poly (3-Hydroxybutyrate) with Polyethylene Glycol (PEG): Thermal behaviour and rheological study

Poly (3-hydroxybutyrate) (PHB) is a biodégradable polymer which its application in industrial was limited due to sensitive to high processing temperature and poor mechanical properties. The thermal and rheological behavior for blends of PHB extracted from dry weight of Jatropha and Poly (ethylene glycol) (PEG) were investigated. Blends of PHB/PEG (PHB 100, PHB 80, PHB 60 and PHB 50) have been prepared through solution blending method. The thermal using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) and rheological behavior using Oscillating Disk Rheometer have been investigated. The results indicate all PHb/PEG blends showed decreased at lowest melting temperature crystallinity (Xc). The TGA result showed that PHB 80 less degraded and suggest better thermal stability compared to PHB 60 and PHB 50. Adding PEG to PHB also improved the rheological behavior of PHB. At higher frequency range, PHB 100 showed less dependency on frequency indicating the elastic structure it has compared to PHB 80, PHB 60 and PHB 50.

The ultra-flexible films of super conductive carbon black/poly(vinylidene fluoride) as electrothermal materials

The electrothermal films of super conductive carbon black/poly(vinylidene fluoride) (PVDF/SCB) were fabricated via solution-blending method. The TEM showed that SCB had the unique branched string bead-like structure. The heating performances of the electrothermal films with SCB content or under different voltages have been studied and the results showed that the prepared films have good electric heating performances and operational stability. Besides, the elongation at break for the films was above 300%, which indicated the films had the excellent flexibility.

Epoxy Composites with Reduced Graphene Oxide-Cellulose Nanofiber Hybrid Filler and Their Application in Concrete Strain and Crack Monitoring.

Advances in nanotechnology have provided approaches for the fabrication of new composite materials for sensing. Flexible sensors can make up for the shortcomings of traditional strain sensors in monitoring the surface strain and cracks of concrete structures. Using reduced graphene oxide (RGO) as a conductive filler, cellulose nanofiber (CNF) as a dispersant and structural skeleton, and waterborne epoxy (WEP) as a polymer matrix, a flexible composite material with piezoresistive effect was prepared by the solution blending and solvent evaporation method. The mechanical, electrical, and electromechanical properties of the composite were investigated. The results show that CNF can significantly improve the dispersion of RGO in the WEP matrix and help to form stable reinforcing and conductive networks, leading to great changes in the mechanical properties and resistivity of the composite. The composite film can withstand large deformations (>55% strain), and the resistance change rate demonstrates a high sensitivity to mechanical strain with a gauge factor of 34–71. Within a 4% strain range, the piezoresistive property of the composite is stable with good linearity and repeatability. The performance of the flexible film sensor made of the composite is tested and it can monitor the strain and crack of the concrete surface well.

Synthesis and photocatalytic activity of MnV13/GO/PANI composite catalysts

Graphene oxide was prepared by modified Hummers method, MnV13/GO composite was prepared by solution blending method, and MnV13/GO/PANI composite catalyst was prepared by interfacial method. The catalyst was characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption-desorption. The results show that the V-O-V bonds of the polymerized heteropoly complex are blue-shifted and the V-Od bonds are red-shifted slightly from conjugation between V-Od and GO lamellae. The photocatalytic properties of the catalyst for malachite green showed that degradation of malachite green was 92.7% after 200 min of UV irradiation. The degradation under sunlight was better than that under ultraviolet light, reaching 97.2%. The degradation of malachite green by the catalyst is a first-order kinetic reaction. We find that such a MnV13/GO/PANI composite exhibits higher photocatalytic activity than MnV13/GO, MnV13 and GO toward the liquid-phase degradation of malachite green under both UV and sunlight irradiation. The presence of synergic effect between PANI and MnV13 is believed to play an essential role in affecting the photoreactivity. At last, the roles of active species in the photocatalytic process are compared by using different types of active species scavengers. The degradation mechanism of the photocatalysts is proposed.

Improvement of water vapor barrier and mechanical properties of sago starch‐kaolinite nanocomposites

AbstractThe composite films of sago starch were prepared by incorporation of various amount of kaolinite (K) and kaolinite intercalated by dimethyl sulfoxide (DMSO) (KD) via solution blending method in order to reduce the water vapor transmission and enhance mechanical properties of starch based films. The kaolinite intercalation by DMSO and the composite films were characterized by using X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope techniques. The result showed that well‐dispersed kaolinite layers were delaminated in the starch matrix attesting to intercalate and exfoliate composite films. The effect of kaolinite content on the water vapor transmission and tensile properties of the composite films was investigated. The water vapor transmission of the starch film (neat starch film ca. 0.132 g.cm3/h) decreased with the addition of K and KD to the starch. It was also observed that the maximum tensile strength (5.18 MPa) was attained for the composite film with 4% by weight of clay content. The improvement in the tensile strength and modulus of starch‐based composites was due to the strong interfacial interaction between matrix and kaolinite clay, correlating to the change of morphology of the starch composite films as revealed by scanning electron microscopy.

X-ray radiation effects on thin film nanocomposites of functionalized and copper coated multi-walled carbon nanotube and poly(methyl methacrylate)

Multi-walled carbon nanotube (MWCNT) and poly(methyl methacrylate) (PMMA) nanocomposites have the potential to be deployed as sensing elements for various applications including ionizing radiation detection. In this work, a 160 kV x-ray ionizing radiation source has been used to study the ionizing radiation dose rate effects on Ferrocene doped MWCNTs, MWCNTs functionalized with - carboxylic acid (COOH), hydrogen peroxide, amine, and MWCNTs coated/ modified with copper. Solution blending method was used in synthesizing the nanocomposites and the synthesized composites were cast on interdigitated electrodes (IDEs) to perform radiation sensing experiments by monitoring changes in the films’ resistance. We have observed a clear, repeatable and proportionate response curve for radiation dose rate measurements with Ferrocene doped MWCNT/PMMA thin film composites. A weaker response is observed for functionalized MWCNT/PMMA films. Ferrocene doped MWCNT/PMMA composite showed the most increased sensitivity to x-ray radiation when compared to all other functional groups reported here and as compared to unfunctionalized MWCNT/PMMA composites. Ferrocene doped MWCNT/PMMA films’ resistance changed over 18% compared to changes observed for unfunctionalized MWCNT/PMMA films of about 6%. Accelerated post radiation recovery of Ferrocene doped MWCNT/PMMA composites using a heat treatment technique is presented. The results of this study suggest that simple sensor elements based on relatively economical MWCNTs could be useful for the detection of ionizing radiation.

The performances of modified single-walled carbon nanotubes/poly(ether ether ketone) composites prepared by solution blending and melt blending

The modified single-walled carbon nanotubes (m-SWCNTs)/poly(ether ether ketone) (PEEK) composites were prepared by solution blending and melt blending, respectively. The mechanical, dielectric, and frictional performances of the m-SWCNTs/PEEK composites obtained by different processing technic were investigated. The poly(aryl ether ketone)s with pyrene (PAEK-Pys) were synthesized through iridium-catalyzed C−H borylation followed by Suzuki coupling. PAEK-Pys were characterized using ultraviolet–visible spectroscopy, proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The polymers were then used for surface modification of pristine SWCNTs. Finally, the m-SWCNTs were used to prepare m-SWCNTs/PEEK composites via co-blending in solution or melt. The mechanical, frictional, and dielectric performance of the m-SWCNTs/PEEK composite by solution blending were better than these in m-SWCNTs/PEEK composite by melt blending. These results suggest that the method of solution blending is more favorable for the dispersion of the SWCNTs in PEEK.

Fabrication and Characterization of Novel Shape-Stabilized Phase Change Materials Based on P(TDA-co-HDA)/GO Composites.

Shape-stabilized phase change materials (SPCMs) are green, reusable energy storage materials. Because the melting temperature of n-alkyl acrylate copolymer is adjustable by controlling the side-chain length, the appropriate melting temperature can be achieved. Poly(tetradecyl acrylate-co-hexadecyl acrylate) (P(TDA-co-HDA)) with a molar ratio of 1:1 and SPCMs were fabricated via an atom transfer radical polymerization (ATRP) method and a solution blending method with P(TDA-co-HDA) as a thermal storage material and graphene oxide (GO) as a supporting substance. In this composite, an SPCM was achieved, which absorbed heat at 29.9 °C and released it at 12.1 °C with a heat storage capacity of 70 J/g at a mass ratio of GO of 10%. The material retained its shape without any leakage at 60 °C, which was much higher than that of the melting temperature of P(TDA-co-HDA). The SPCMs exhibited good crystallization behaviors and excellent thermal reliabilities after 100 thermal cycles. The thermal properties of the P(TDA-co-HDA)/GO composite PCMs with various GO loadings were also investigated. The novel shape-stabilized PCMs fabricated in this study have potential uses in thermal energy storage applications.

Influence of amine-functionalised graphene oxide filler on mechanical and insulating property of epoxy nanocomposites

Graphene oxide incorporated epoxy nanocomposites were prepared using synthesised graphene oxide (GO) and amine functionalised graphene oxide (AGO) in various loading (0–0.6) wt% by solution blending method. As synthesised GO and AGO were characterised by Fourier transform infrared spectrum (FTIR), x-ray diffraction (XRD) and Thermogravimetric (TG) analysis. The dielectric permittivity and loss factor of GO/AGO epoxy nanocomposites were found out by impedance analyser in the frequency range of 101 to 106 Hz. The dielectric endurance of GO/AGO epoxy nanocomposites was investigated by dielectric breakdown strength and electrical resistivity. It was found that for filler loadings up to 0.4 wt% of both GO and AGO, there was a proportionate change in properties due to homogeneous dispersion. The study shows surface functionalised AGO-epoxy nanocomposites have shown better permittivity, loss factor, and breakdown strength than neat epoxy and GO-epoxy composites.

Enhanced Thermal Conductivity of Epoxy Composites Filled with 2D Transition Metal Carbides (MXenes) with Ultralow Loading

With the development of electronic devices such as integrated circuits toward the continual increase in power density and consumption, the efficient heat dissipation and low thermal expansion of materials become one of the most important issue. However, conventional polymers have the problem of poor thermal dissipation performance, which hinder application for electronic devices. In this work, the two-dimensional material, MXene (Ti3C2), is used as the reinforcement additive to optimize the thermal properties of polymers. We reported the preparation of multilayer Ti3C2 MXene by HF etching method and obtained few-layer Ti3C2 MXene by simple ultrasonication. Meanwhile, Ti3C2/epoxy composites were prepared by a solution blending method. The results show that the thermal properties of the composites are improved in comparison with the neat epoxy. Thermal conductivity value (0.587 W/mK) of epoxy composite with only 1.0 wt% Ti3C2 MXene fillers, is increased by 141.3% compared with that of neat epoxy. In addition, the composite presents an increased glass transition temperature, high thermal stability and lower coefficient of thermal expansion. This work is of great significance for the research of high-performance composite materials.

Thermal Stability and Flame Retardancy Properties of Epoxy Resin Modified with Functionalized Graphene Oxide Containing Phosphorus and Silicon Elements.

Phosphorus- and silicon-modified graphene oxide was prepared to improve the thermal stability and flame retardancy properties of epoxy resin. 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and vinyltriethoxysilane (VTES) were successfully grafted onto the surface of graphene oxide (GO) through solvothermal synthesis and hydrolysis–condensation reaction, respectively. Subsequently, the functionalized graphene oxide grafted by DOPO and VTES (DOPO–VTES–GO) was incorporated into the epoxy resin by the solution blending method. The effect of DOPO–VTES–GO on the thermal stability and flame-retardant properties of epoxy resin was systematically studied. Thermogravimetric analysis showed that the thermal stability and char residue yield of DOPO–VTES–GO/epoxy were increased obviously compared with those of pure epoxy resin and DOPO–GO/epoxy. Cone calorimeter test results showed that DOPO–VTES–GO/epoxy had better flame retardancy than pure epoxy resin and DOPO–GO/epoxy on reducing the peak of heat release rate, total heat release, and total smoke production. Furthermore, the char residue after the cone calorimeter tests was investigated by scanning electron microscopy–energy-dispersive X-ray spectrometry, Raman spectroscopy, and Fourier transform infrared measurements. These results demonstrated that the DOPO–VTES–GO can enhance the graphitization degree of char residues and promote the formation of the thermally stable char. In addition, the mechanism of flame retardancy was proposed, and DOPO–VTES–GO exerts the synergistic effect mainly by means of catalytic charring in the condensed phase and capturing hydroxyl or hydrogen radicals from thermal decomposition of epoxy resin in the gas phase. This work provides novel insights into the preparation of phosphorus–silicon–graphene oxide ternary synergistic flame retardants for thermosetting polymer materials.

Sub-kilogram-scale synthesis of highly dispersible zirconia nanoparticles for hybrid optical resins

Abstract We report the synthesis of highly dispersible zirconia (ZrO2) nanoparticles in sub-kilogram-scale by hydrothermal process coupled with alkaline hydrogen peroxide (AHP) treatment, with detailed studies on the effects of experimental parameters. Under optimized experimental condition, which was hydrothermal reaction at 110 °C for 6 h with mole ratio of sodium hydrate to zirconium carbonate basic in reactants as 2.3, pure-phase cubic-ZrO2 nanoparticles are obtained. Followed by AHP treatment of the ZrO2 nanoparticles at 50 °C for 5 h in 0.4 M hydrogen peroxide and 4 M sodium hydrate, the dispersibility of ZrO2 nanoparticles in aqueous suspension was enhanced due to the introduced Zr-OH groups on the surface. ZrO2 nanodispersion with solid content of 37 wt% in aqueous solution exhibited a uniform hydrodynamic size of 14.15 ± 5.834 nm and was stable for over six months without significant aggregates. Transparent hybrid optical resins with tunable refractive index in the range of 1.55–1.71 were prepared by solution blending method using ZrO2 nanoparticles as composite fillers in polyvinyl alcohol substrate. Compared with pure polyvinyl alcohol resin, the hybrid resin exhibits significant enhanced mechanical properties. Sub-kilogram-scale preparation of highly aqueous dispersible ZrO2 nanoparticles offers possibility for practical applications.

Enhanced thermal stability and mechanical property of EVA nanocomposites upon addition of organo-intercalated LDH nanoparticles

Organo-intercalated layered double hydroxides (LDHs)/ethylene vinyl acetate (EVA) nanocomposites were synthesized using the solution blending method. Pristine layered double hydroxides are not compatible with hydrophobic polymer matrix due to their hydrophilic property. As an attempt to improve the compatibility of LDHs with hydrophobic EVA, positively charged LDH surface was modified by incorporating various anionic surfactants. Surfactants were selected by considering the length of aliphatic chains conjugated with and without an aromatic ring such as sodium dodecyl sulfate (DS), sodium dodecylbenzene sulfonate (DBS), and stearate (SA). The organo-intercalated LDHs into EVA resulted in enhanced thermal stability (ΔT0.5 = 7–19 °C, T0.5: temperature at 50 wt% weight loss) and mechanical strength of the EVA nanocomposites depending on the type and the loading concentration of organo-intercalated LDHs compared to these of intact EVA. Especially, SA-LDH had higher enhancement efficiency in elongation at break than DS-LDH and DBS-LDH. It is, therefore, concluded that organo-intercalated LDHs using suitable anionic surfactants are potential inorganic materials that can be considered as a nanofiller with high thermal stability and mechanical property.

High degree sulfonated poly(ether ether ketone) blend with polyvinylidene fluoride as a potential proton-conducting membrane fuel cell

Sulfonated poly(ether ether ketone) (sPEEK) membrane is a promising proton-conducting membrane for fuel cell. However, the performance and lifetime of sPEEK membrane depend on the degree of sulfonation (DS). High DS of sPEEK increases the performance, but the mechanical properties could deteriorate progressively which affect its lifetime. Thus, this study investigated the effect of adding polyvinylidene fluoride (PVDF) into high DS (80%) of sPEEK through solution blending method toward its physicochemical properties and morphology structures. The PVDF concentration was varied to 5, 10, 15, and 20 wt% relative to the sPEEK content. The existence of hydrophobic PVDF in 80% sPEEK improved the mechanical properties where the water uptake and swelling degree of membrane decreased, whereas the tensile strength increased. The sPEEK/PVDF 15 exhibited the highest proton conductivity (46.23 mS cm−1) at 80°C. Incorporating PVDF into high DS of sPEEK enhanced the mechanical properties which can be used as a proton-conducting membrane for fuel cell that may improve the performance and prolong the lifetime of the cell.

Preparation and properties of reduced graphene oxide/polyimide composite films

We have successfully prepared reduced graphene oxide/polyimide (RGO/PI) composite films by solution blending method and thermal annealing. The effects of contents of graphene oxides (GOs) and different anneal temperatures were mainly investigated. The oxygen-containing groups on GOs’ surface can lead to the formation of hydrogen bonds between GO and PI, which are benefit for GO to disperse in PI uniformly and improve PI properties. The coefficient of thermal expansion decreased drastically from 15.46 μm/(m·°C) to 3.94 μm/(m·°C) within the range of 100–300°C, and the glass transition temperature increased. These improvements can help RGO/PI films resist the high temperature when preparing photoelectric devices and get high-performance flexible photoelectric devices. The elastic modulus of RGO/PI films increased slightly, and tensile strength of RGO/PI films remained the same, while the elongation at break decreased.

Self-cleaning Anti-fouling TiO2/Poly(aryl ether sulfone) Composite Ultrafiltration Membranes

A series of novel TiO2/poly(aryl ether sulfone) ultrafiltration membranes with anti-fouling and self-cleaning properties was designed and prepared. First, anti-photocatalytic degraded fluorine contained poly(aryl ether sulfone) matrix(PAES-F) was synthesized. Then the composite membranes were prepared via TiO2 nanoparticles and PAES-F polymer matrix by solution blending and non-solvent induced phase inversion methods. Further, separation efficiency, fouling behavior and self-cleaning property of the composite ultrafiltration(UF) membranes were investigated by dead-end filtration experiments using a polyacrylamide solution. The composite UF membranes exhibited outstanding self-cleaning efficiency and anti-photocatalytic degraded property after exposure to simulated sunlight irradiation. The water flux recovery ratios(FRR) of the optimal composite UF membranes could reach 74.24%, which was attributable to photocatalytic degradation of the organic contaminant by TiO2. And the retention rates of the composite UF membranes could maintain over 97%, which indicated the excellent photocatalytic degradation resistance of the fluorine contained PAES-F matrix. The novel high performance composite UF membranes have a broad application prospect in water treatment.

Preparation and mechanical performances of carbon fiber reinforced epoxy composites by Mxene nanosheets coating

Known as a new kind of two dimensional materials, Mxene has attracted much attention in applications in polymer based composites because of their unique mechanical, thermal, and electrical properties. In this work, we report on the synergistic enhancement of Ti3C2Tx Mxene nanosheets coated on carbon fiber (CF/Mxene) to epoxy resin. Ti3C2Tx Mxene nanosheets were synthesized by HF etching and sonicating and used as surface sizing agent to modify NH2-CF by electrostatic self-assembly. NH2-CF/Mxene reinforced epoxy resin (NH2-CF/Mxene/EP) composites were prepared using a solution blending method. Their structure, morphology and performance were investigated. It is observed that Mxene possesses nanosheet structure and functional groups which are responsible for improving interfacial adhesion between NH2-CF and EP resin. The structural characterization showed that Mxene nanosheets are successfully attached to the NH2-CF surfaces. Importantly, the tensile strength, flexural strength, shear strength, and impact strength of NH2-CF/Mxene/EP composites have respectively increased by 40.8, 45.9, 38.5, and 74.4% compared to those of pristine CF/EP composites, suggesting that Ti3C2Tx Mxene nanosheets use is a promising approach for improving the mechanical properties of EP-based composites.

The influence of titanium dioxide nanofiller ratio on morphology and surface properties of TiO2/chitosan nanocomposite

Abstract In the present study, different ratios of TiO2-chitosan nanocomposite (nT-CS) [1:1(nT-CS1), 1:2 (nT-CS2), and 1:5 (nT-CS5)] were prepared by using the method of solution blending. The characterization of the prepared nanocomposite was done through different techniques such as Fourier transform Infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), and surface area analysis (BET, BJH). The results of FTIR and Raman spectroscopy indicate the appearance and the shifting of main bands of titanium dioxide and chitosan. In addition, the XRD results show shifting of main bands and change in crystal structure of chitosan. The images of AFM and SEM indicate that the TiO2 nanoparticles homogenously distributed throughout the chitosan matrix with an appearance of some agglomeration. The BET analysis indicates that nanocomposite with ratio 1:2 (nT-CS2) had the highest surface area 113 m2/g. Besides that, this ratio showed high adsorption of Direct Violet 51 (DV51) from its aqueous solutions.

Long‐range dipole–dipole energy transfer enhancement via addition of SiO2/TiO2 nanocomposite in PFO/MEH‐PPV hybrid thin films

ABSTRACTDifferent weight ratios of poly(9,9‐dioctylfluorene‐2,7‐diyl) (PFO)/poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) hybrid thin films, with and without a SiO2/TiO2 nanocomposite (NC), were successfully prepared using a solution blending method. All samples were deposited onto glass substrates by a spin coating technique to produce homogeneous thin films. The effect of the SiO2/TiO2 NC on the enhancement of the energy transfer mechanism in the PFO/MEH‐PPV hybrids was investigated. The energy transfer parameters were calculated on the basis of the absorption and emission measurements. The long‐range dipole–dipole energy transfer (Förster type) between the acceptor and donor molecules was enhanced in the presence of the SiO2/TiO2 NC in the hybrid thin films. The addition of the SiO2/TiO2 NC in the PFO/MEH‐PPV hybrids reduced the distance between the donor and acceptor molecules more than the individual addition of SiO2 or TiO2 nanoparticles. Moreover, the direct relationships between the acceptor contents and energy transfer parameters, such as the energy transfer radius (RDA), energy transfer efficiency (η), and energy transfer probability (PDA), were estimated using theoretical fittings. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47845.