Modified Epoxy Nanocomposites Research Articles

Experimental investigation and characterisation of two-phase graphene modified epoxy nanocomposites

Experimental investigation and characterisation of two-phase graphene modified epoxy nanocomposites

Use of absorber plate built of ZnO/PVC/Bioactivation modified epoxy nanocomposites to improvement of double-effect Solar Distiller productivity analyzing the Energy, Exergo-environment and Enviro-economical

In this study, solar thermal desalination methods were developed to enhance the day to day efficiency of solar distillers by improving their portability and water purification properties. The performance of solar stills is highly contingent on environmental factors, making it essential to address these variables. To achieve this, a double-slope single basin solar distiller (DSBD) was upgraded by incorporating a partially coated absorber plate with ZnO/PVC/Bioactive nanocomposite (ZPBN), which was subsequently examined for its impact on drinking water production from multiple perspectives, including energy, exergy, environmental, and economic considerations. The ZPBN material was synthesized using the solvent casting technique, and its properties were comprehensively characterized through various analytical methods. X-ray diffraction (XRD) analysis revealed a regular crystalline lattice structure amidst an amorphous background, and scanning electron microscopy (SEM) images confirmed its surface performance. The presence of ZnO nanoparticles within the PVC and bioactive matrix imparted enhanced thermal characteristics to the DSBD, including higher temperatures, specific heats, and thermal stability compared to the ZPBN. The study demonstrated that the introduction of ZPBN significantly increased drinking water yield by up to 126% due to its enhanced absorption of solar energy. Furthermore, the energy efficiency of the DSBD improved by 0.44%, while its exergy efficiency decreased by 0.25% when compared to a conventional double slope single basin solar distiller (CDSBD) under the tropical climate conditions of Vijayawada, India. In terms of energy matrices, the ZPBN-coated basin area exhibited minimum and maximum energy payback times of 6.55 years and 0.15 years, respectively. Over its lifetime, the DSBD was found to reduce carbon dioxide emissions by 2.97 tonnes and offered the lowest cost per litre, amounting to $0.0360. The incorporation of ZPBN on the absorber plate within the DSBD resulted in excellent environmental and energy economies, with values of 4.640 kWh/$ and $83.210, respectively.

Experimental Investigation and Characterization of Two-Phase Graphene Modified Epoxy Nanocomposites.

Experimental Investigation and Characterization of Two-Phase Graphene Modified Epoxy Nanocomposites.

Synergistic effect of nanotextured graphene oxide modified with hollow silica microparticles on mechanical and thermal properties of epoxy nanocomposites

The current study explores the synergistic effect of graphene oxide and nano & hollow silica particle composite as a reinforcing agent for improved mechanical and thermal properties of tetrafunctional epoxy nanocomposites. The unique architecture of the reinforcing agent prevents the agglomeration of graphene oxide sheets during the drying process and during the process of incorporation into epoxy matrices. Graphene oxide was functionalized with nano-silica and in-situ decorated with flexible hollow micro-silica particles. The nano-silica reduces the cohesive forces among the nano-textured graphene sheets and prevents restacking during the drying process. The hollow micro-silica particles act as a physical barrier, preventing restacking and agglomeration. The silica particles are amine-functionalized, facilitating chemical bonding between graphene oxide and epoxy. Additionally, the flexible and hollow nature of particles does not create any porosity in the matrix and participates in improving mechanical properties. The SGO-SiO2 modified epoxy nanocomposites were fabricated where loading was varied from 0.25 to 1 wt%. Modified epoxy nanocomposites showed excellent improvement of more than 40% compared to neat epoxy for compressive, flexural, and fracture properties with the loading of SGO-SiO2 in the range 0.75 wt% to 1 wt%.

Investigation on the physio-mechanical properties of carpet waste polymer composites incorporated with multi-wall carbon nanotube (MWCNT)

In the structural functions of polymer components, the material's thermal stability and moisture absorption efficiency play a vital role in defining durability and physio-mechanical performance. This article emphasizes the experimental investigation of polymer (Epoxy) composites fabricated from carpet waste and Carbon nanomaterial (CBN). The supplement of Multi-wall carbon nanotube (MWCNT) into the epoxy/carpet waste polymer composites is proposed to enhance the physio-mechanical properties. The experimentation was performed to check the synergistic effect of nanomaterials in five configurations with different wt.% of MWCNT in the proposed composites. The water absorption, swelling rate, fire retardant and compression performance of the discarded carpet polymer composite modified with MWCNT have been investigated. The effect of water dipping and dry condition was completed to evaluate the composite feasibility. In addition, the fire-retardant properties of developed materials were analyzed using the fire (horizontal) setup process. The results found that incorporating the MWCNT nanoparticles into discarded carpet polymer composites can improve the compression strength. It was noticed that the few quantities of water were absorbed with less swelling effect at the 0.25 wt.% of MWCNT. The modified epoxy nanocomposites have higher specific properties values when compared to neat (discarded carpet polymer) composites. The fire retardancy properties have been enhanced remarkably with a supplement of lower nanomaterials wt.%. The findings show that the proposed carpet waste/MWCNT/polymer composites could be recommended for lightweight functions such as roadside barriers, wall tiles, toys, decorative frames, insulating materials, etc.

Mechanical and wear characteristics of glass fiber reinforced modified epoxy nano composites – A review

Polymer nanocomposites have observed massive development in modern era due to their possible applications in a wide range of engineering industries. It is prominent that the combinations of nano fillers with polymer matrix offer materials with excellent properties, which are not feasible by using an individual element. The investigation on mechanical properties such as tensile strength, flexural strength, impact strength, micro hardness, interlaminar shear strength and compression strength was carried out for the manufactured reinforced composites. The dry Sliding wear test carried out by using pin on disc apparatus. It is proved that the wear loss was increased proportionally with load and sliding velocity. The morphological behaviour was examined by the use of scanning electron microscope for visualizing the uniform and homogeneous dispersion of nanoclay into the epoxy matrix. The homogeneity dispersion of the nanoclay is confirmed from the Scanning Electron Microscope (SEM) examination.

Halloysite nanotube reinforcement endows ameliorated fracture resistance of seawater aged basalt/epoxy composites

Seawater aging-dominated delamination failure is a critical design parameter for marine composites. Modification of matrix with nanosized reinforcements of fiber-reinforced polymer composites comes forward as an effective way to improve the delamination resistance of marine composites. In this study, we aimed to investigate experimentally the effect of halloysite nanotube nanoreinforcements on the fracture performance of artificial seawater aged basalt–epoxy composites. For this, we introduced various amounts of halloysite nanotubes into the epoxy and the halloysite nanotube–epoxy mixtures were used to impregnate to basalt fabrics via vacuum-assisted resin transfer molding, subsequently. Fracture performances of the halloysite nanotubes modified epoxy and basalt/epoxy composite laminated were evaluated separately. Single edge notched tensile tests were conducted on halloysite nanotube modified epoxy nanocomposites and the average stress intensity factor (KIC) was increased from 1.65 to 2.36 MPa.m1/2 (by 43%) with the incorporation of 2 wt % halloysite nanotubes. The interlaminar shear strength and Mode-I interlaminar fracture toughness (GIC) of basalt–epoxy hybrid composites were enhanced from 36.1 to 42.9 MPa and from 1.22 to 1.44 kJ/m2, respectively. Moreover, the hybrid composites exhibited improved seawater aging performance by almost 52% and 34% in interlaminar shear strength and GIC values compared to the neat basalt-epoxy composites after conditioning in seawater for six months, respectively. We proposed a model to represent fracture behavior of the seawater aged hybrid composite based on scanning electron microscopy and infrared spectroscopy analyses.

Toughening of high performance tetrafunctional epoxy with poly(allyl amine) grafted graphene oxide

The mechanical and thermal properties of epoxy composites were improved by using poly (allyl amine) (PAA) grafted graphene oxide (GO) as a toughening agent. The GO was first converted to GO-COOH where all the hydroxyl groups on the basal plane were converted to COOH containing groups. GO-COOH was reacted with PAA to yield GO-g-PAA. The effect of PAA grafted GO nanosheets as fillers on mechanical and thermal properties of aerospace grade epoxy was studied. Epoxy nanocomposites containing graphene oxide (GO) and GO-g-PAA nanosheets were fabricated by incorporating 0.35 to 1.4 wt% of filler. GO-g-PAA modified epoxy nanocomposites showed excellent improvement in flexural, compression and fracture properties compared to neat epoxy and GO modified epoxy. Fracture toughness increased from 0.94 MPa m to 1/2 for neat epoxy to 1.75 MPa m-1/2 (87%) for epoxy nanocomposites modified with 0.7 wt% of GO-g-PAA nanosheets. The temperature for 5% weight loss showed drastic improvement of 24 °C for epoxy nanocomposites modified with 0.7 wt% of GO-g-PAA nanosheets. The examination of fractured surfaces of modified epoxy nanocomposites showed better interaction of GO-g-PAA nanosheets with epoxy compared to GO nanosheets.

Effect of pre and Post-Dispersion on Electro-Thermo-Mechanical Properties of a Graphene Enhanced Epoxy

Graphene nanoplatelet (GNP) modified epoxy nanocomposites are becoming attractive to aerospace due to possible improvements in their mechanical, electrical and thermal properties at no weight cost. The process of obtaining reliable material systems provides many challenges, especially at larger scale (a volume effect). This paper reports on the main fabrication stages of GNP-based epoxy composites, namely (i) pre-dispersion, (ii) dispersion, and (iii) post-dispersion. Each stage is developed to show the interest and potential it delivers for property enhancement. Chemical modification of GNP is presented; functionalisation by Triton X-100 shows elastic modulus improvements of the epoxy at low particle content (≤3%). The post-dispersion step as an alignment of GNP into the epoxy by an electrical field is discussed. The electrical conductivity is below the simulated percolation threshold and an improvement of the thermal diffusivity of 220% when compared to non-oriented GNP epoxy sample is achieved. The work demonstrates how the addition of functionalised graphene platelets to an epoxy resin will allow it to act as electrical and thermal conductor rather than as insulator

Viscoelastic damping behaviour of cup stacked carbon nanotube modified epoxy nanocomposites with tailored interfacial condition and re-agglomeration

Abstract Re-agglomeration is a natural phenomenon occurring in certain processing methods used in the fabrication of nanocomposites. The work describes the tailoring of the interfacial bonding and morphology in the re-agglomeration of cup stacked carbon nanotubes (CSNTs) modified RTM6 epoxy nanocomposite for potential damping applications. Mechanical and electrical properties were analysed to inform the dispersion and interfacial conditions within the nanocomposites. Samples with resin infused re-agglomerates revealed certain advantages in both mechanical and damping performance. This finding disrupted the traditional compromise between a favourable mechanical property and the energy dissipation of a homogeneously dispersed nanocomposite, allows both properties to be improved under certain interfacial bonding condition. It is proposed that a controlled agglomeration may afford a superior properties combination without sacrificing one another.

Influence of temperature on tensile behavior of multiwalled carbon nanotube modified epoxy nanocomposites

Abstract

Mechanical property characterization of carbon nanotube modified polymeric nanocomposites by computer modeling

This paper reports a two-step modeling approach for predicting the effective mechanical properties of polymeric nanocomposites modified with single walled carbon nanotube (SWNT). In step one, the nano-heterostructures of the nanocomposites were represented by 3-D nanoscale cylindrical, square, or hexagonal prismatic representative volume elements (RVEs). Each RVE contained a long or a short carbon nanotube (CNT) and consisted of three phases, i.e., CNT, matrix, and interphase. The mechanical properties of each RVE were extracted from the modeling results of the RVE undergone three load tests, i.e., uniaxial tensile test, lateral expansion test, and axial torsional test, using appropriately derived formulae. The effects of the volume fraction of CNTs on the mechanical properties of the RVEs were studied. The equivalent mechanical properties of the nano-heterostructures were obtained by averaging the mechanical properties extracted from each RVE. In step two, micro/macroscale nanocomposites were represented by a 3-D microscale unit cell which was discretized into cubic elements. Using Monte Carlo method, each element was assigned the averaged mechanical properties of the RVEs with random CNT orientation and length type. The overall effective mechanical properties of the nanocomposites were predicted by a tensile test on the unit cell. The modeling results by this proposed approach was compared with and validated by the experimental data of the SWNT modified epoxy nanocomposites.

Synthesis and characterization of organic-inorganic hybrid clay filled and bismaleimide—siloxane modified epoxy nanocomposites

Organic-inorganic hybrids involving organo-modified montmorillonite (OMMT) clay and tetraglycidyl diamino diphenyl methane epoxy (TGDDM) were prepared via in situ polymerization by the homogeneous dispersion of various percentages (1–5% w/w) of clay in epoxy matrix resin. The resulting homogeneous epoxy—clay hybrids were modified with 10 wt% of hydroxyl terminated polydiemthyl siloxane (HTPDMS) using γ—aminopropyltriethoxysilane (γ-APS) as coupling agent in the presence of tin catalyst. The siliconized epoxy-clay prepolymers were further modified separately with 15 wt% of bismaleimide (BMI) monomers and cured with diaminodiphenylmethane. The reactions involved during the curing process between epoxy resin, siloxane and BMI were confirmed by using FTIR and DSC curing analysis. The differential scanning calorimetry (DSC) show that the significant increase in glass transition temperatures in the clay filled hybrid epoxy systems than that of neat epoxy resin. The data obtained from thermal studies indicates that the appreciable improvement in hybrid systems was due to the incorporation of MMT clay, BMI and siloxane into epoxy systems. Scanning electron microscopy (SEM) of the hybrid systems show that the homogenous morphology. X-ray diffraction analysis of the clay hybrid systems shows that the amorphous diffraction patterns and the peaks are broadened and nearly disappeared after 24 h swelling, suggesting the formation of exfoliated structure.

Studies on thermal, mechanical and morphological properties of organoclay filled azomethine modified epoxy nanocomposites

Inter cross-linked networks of organoclay-filled, azomethine-modified epoxy nanocomposites have been developed. Two types of azomethine epoxies (AE1 and AE2) incorporated into diglycidyl ether of bisphenol A (DGEBA) epoxy resin with varying percentages (5, 10 and 15%) were cured with diamine diphenyl methane (DDM). The azomethine epoxies were synthesized and characterized by Fourier transform infrared and 1H-NMR spectroscopy. The incorporation of azomethine epoxies into DGEBA epoxy resin improved both thermal and mechanical properties to an appreciable extent. The introduction of organoclay into DGEBA epoxy resin exhibited almost similar characteristics to that of the azomethine-modified DGEBA epoxy resin. Both azomethine epoxy and organoclay have been incorporated into DGEBA epoxy resin in order to improve the thermal and mechanical properties in comparing other modified epoxies. The glass transition temperature and thermal degradation temperature of azomethine-modified epoxies, organoclay-filled epoxy and organoclay-filled azomethine-modified DGEBA epoxies were determined by using differential scanning calorimeter and thermogravimetric analysis. The mechanical properties, namely the tensile strength, flexural strength and impact strength of the resultant nanocomposites were studied as per ASTM standards. X-ray diffraction studies of the cured nanocomposites indicate that the organophillic montmorillonite clay was exfoliated into the cured product. The homogeneous morphology of azomethine-modified DGEBA epoxy and organoclay-filled azomethine-modified epoxy were ascertained by scanning electron microscopy.

Thermo-oxidative degradation of novel epoxy containing silicon and phosphorous nanocomposites

Modified epoxy nanocomposites containing silicon and phosphorous was prepared and compared with pure epoxy. The study of thermo-oxidative degradation of modified epoxy nanocomposites and pure epoxy has been utilized by thermal analysis. The thermal stability of modified epoxy nanocomposites is not superior to that of the pure epoxy at low temperature, however, the char yield of modified epoxy nanocomposites is higher than that of the pure epoxy at 800 °C in air atmosphere. The modified epoxy nanocomposites possess better thermal stability at high temperature range. The values of the limiting oxygen index of pure epoxy and modified epoxy nanocomposites are 24 and 32, respectively. This indicates that modified epoxy nanocomposites possesses better flame retardance. By the Kissinger’s method, the activation energies of thermo-oxidative degradation for epoxy nanocomposites are less than those of thermo-oxidative degradation for pure epoxy in first stage of thermo-oxidative degradation. However, the activation energies of thermo-oxidative degradation for epoxy nanocomposites are more than those of thermo-oxidative degradation for pure epoxy in second stage of thermo-oxidative degradation.

Synthesis, characterization and thermal properties of novel epoxy containing silicon and phosphorus nanocomposites by sol–gel method

Organic–inorganic hybrids were prepared using diglycidyl ether of bisphenol A (DGEBA) type epoxy and tetraethoxysilane via the sol–gel process. The DGEBA type epoxy was modified by a coupling agent to improve the compatibility of the organic and inorganic phases. The sol–gel technique was used successfully to incorporate silicon and phosphorus into the network of hybrids increasing flame retardance. Fourier transform infrared spectroscopy and 29Si nuclear magnetic resonance spectroscopy were used to characterize the structure of the hybrids. In condensed siloxane species for TEOS, silicon atoms through mono-, di-, tri-, and tetra-substituted siloxane bonds are designated as Q 1, Q 2, Q 3, Q 4, respectively. For 3-isocyanatopropyltriethoxysilane and diethylphosphatoethyltriethoxysilane, mono-, di-, tri-, tetra-substituted siloxane bonds are designated as T 1, T 2, T 3. Results revealed that Q 4, Q 3, T 3 are the major environments forming a network structure. The morphology of the ceramer was examined by scanning electron microscopy and Si mapping. Particle sizes were below 100 nm. The hybrids were nanocomposites. The char yield of pure epoxy resin was 14.8 wt.% and that of modified epoxy nanocomposite was 31 wt.% at 800 °C. A higher char yield enhances the flame retardance. Values of limiting oxygen index of pure epoxy and modified epoxy nanocomposites are 24 and 32, respectively, indicating that modified epoxy nanocomposites possess better flame retardance than the pure epoxy resin.