MMT Nanoparticles Research Articles

Quasi‐static and high‐rate in‐plane shear tests on aramid and carbon fiber woven composites featuring a nanoparticle‐enriched high‐density polyethylene matrix

AbstractNanoparticles are known to enable the modification of the properties of the material they are integrated into. In the context of ballistic protection, previous works have demonstrated that graphene and Montmorillonite (MMT) particles included in high‐density polyethylene (HD‐PE) and used as a matrix enable an increase in the ballistic performance, of consolidated woven aramid fabrics. Furthermore, the ballistic performance has been reported to be influenced by the in‐plane shear properties of the impacted materials. In this context, quasi‐static and high‐rate in‐plane shear tests have been conducted on two types of reinforcements, aramid, and carbon woven fabrics, consolidated by a high‐density polyethylene matrix enriched by graphene, MMT and a mix of graphene and MMT nanoparticles. The conducted investigations provide for the first time in the literature the results of high‐rate in‐plane shear tests on aramid woven reinforcement consolidated with nanoparticle‐enriched and not enriched high‐density polyethylene composites. Despite the use of the same reinforcement and enriched matrix material as in previous works of literature, no significant differences in terms of in‐plane shear behavior have been observed for any of the different types of nanoparticles integrated into the matrix. Nevertheless, the obtained results demonstrate a clear strain rate sensitivity of the tested materials.Highlights Aramid and carbon fabrics were consolidated with nanoparticle‐enriched HD‐PE Quasi‐static and high‐rate in‐plane shear tests were conducted No influence of the nanoparticles could be identified A clear strain‐rate sensitivity could be identified for both composites

Ni Nanoparticles Supported Montmorillonite Clay for Selective Catalytic Transfer Hydrodeoxygenation of Vanillin into 2‐Methoxy‐4‐methylphenol

AbstractThe targeted catalytic transfer hydrodeoxygenation (CTHDO) of vanillin (VAN) to 2‐methoxy‐4‐methylphenol (MMP) holds promise as a noteworthy subject in the domain of bio‐oil utilization, offering potential as a future biofuel and finding versatile use in fragrances and pharmaceutical industry. In this study, stable, cost‐effective Ni nanoparticles supported on montmorillonite (MMT) clay was synthesized for eco‐friendly, alcohol‐mediated CTHDO of VAN to MMP. The Ni(10 %)/MMT catalyst achieved >99 % VAN conversion and 95.2 % MMP selectivity using isopropanol (IPA) as a solvent and hydrogen donor. Characterization encompassing PXRD, SEM, TEM, and XPS confirmed successful Ni integration onto MMT. NH3‐TPD, pyridine‐IR, and H2‐TPR analysis evaluated catalyst surface acidity and reducibility. The synergy between surface‐modulated acidity of MMT and Ni nanoparticles collectively facilitated IPA and VAN activation, driving CTHDO performance. The Ni(10 %)/MMT catalyst displayed sustained activity over five recycles. Its exceptional stability and performance underscore its potential as an eco‐friendly, sustainable, non‐noble transition metal‐based catalyst for the hydrogenating lignin bio‐oil model compounds, contributing to greener catalytic advancements.

Polymer-clay nanofibrous wound dressing materials containing different boron compounds

BackgroundMontmorillonite (MMT) is a biocompatible nanoclay and its incorporation into polymeric matrix not only improves the polymer’s wettability/biodegradability, but also enhances cellular proliferation, and differentiation. On the other hand, the positive effect of boron (B) on the healing cascade and its antibacterial properties have drawn the attention of researchers. Materials & methodsIn this regard, B compounds in different chemical structures, boron nitride (BN), zinc borate (ZB), and phenylboronic acid (PBA), were adsorbed onto MMT and then, poly (lactic acid) (PLA) based MMT/B including micron/submicron fibers were fabricated by electrospinning. ResultsThe incorporation of MMT nanoparticles into the PLA demonstrated a porous fiber topography with enhanced thermal properties, water uptake capacity, and antibacterial effect. Furthermore, the composites including BN, ZB, and PBA showed bacteriostatic effects against Gram-negative and Gram-positive pathogenic bacteria (Escherichia coli and Staphylococcus aureus). In-vitro cell culture studies performed with human dermal fibroblasts (HDF) indicated the non-toxic effect of B compounds. The results showed that incorporation of MMT supported cell adhesion and proliferation, and further addition of B compounds especially PBA increased cell viability for 14 days. ConclusionThe results illustrated the acceptable characteristics of the B-containing composites and their favorable effect on the cells, demonstrating their potential as a skin tissue engineering product.

Investigating the lubrication performance of vegetable oils reinforced with HNT and MMT nanoclays as green lubricant additives

Currently, technology demands a sustainable and more environmentally friendly lubricant. In addition, government regulations and recent concern about using petroleum-based lubricants have increased research on environmentally friendly lubricants such as vegetable oils. This study investigates the lubrication performance of corn and peanut oils reinforced with different concentrations of Halloysite clay nanotubes (HNTs) and Montmorillonite nanoclay (MMT) as green lubricant additives. Block-on-ring wear tests following the ASTM G-077-17 standard procedure were conducted to investigate the effect of different nanoparticle (NP) concentrations on the coefficient of friction (COF) and wear volume loss. Different surface analytical methods, including scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and profilometry, were used to analyze the worn surfaces. Additionally, the lubrication performance of the newly developed vegetable oil-based nanolubricants was evaluated in an industrial-type application through tapping torque tests. The tribological results revealed that the coefficient of friction (COF) for the corn oil was lowered by 56% and 77% with the addition of HNT and MMT NPs, respectively, compared to corn oil without additives. Similarly, the COF for the peanut oil was lowered by 66% and 81% with the addition of HNT and MMT NPs, respectively, compared to peanut oil without additives. Moreover, the volumetric wear decreased by 78% and 75% for the corn oil and 67% and 62% for the peanut oil when using HNT and MMT NPs as lubricant additives, respectively. Therefore, based on the experimental results, the authors conclude that vegetable oils reinforced with HNT and MMT nanoclays have the potential to be used as good biodegradable nanolubricants.

Organomodified nanoclay with boron compounds is improving structural and antibacterial properties of nanofibrous matrices

In this study, nanofibrous polymeric matrices were successfully developed with nanoclay, montmorillonite (MMT) and various boron (B) compounds, which were known to have positive effects on the wound healing with elevated antibacterial properties. For this purpose, MMT was modified with quaternary ammonium salt, trimethyl octadecyl ammonium bromide (TMOD), and boron compounds, boron nitride (BN), zinc borate (ZB), or phenylboronic acid (PBA) were adsorbed on organomodified MMT (OMMT). Then, poly (lactic acid) (PLA) based nanofibrous PLA-OMMT/B composites were fabricated via electrospinning. Modification of MMT nanoparticles with TMOD occurred through ion-exchange reaction and led to better homogenous fibrous structures which exhibited dramatic inhibition for gram-positive bacteria. Moreover, composites with ZB and PBA demonstrated both bacteriostatic and bactericidal effects for gram-positive and gram-negative bacteria. The chemical structures of the matrices were evaluated through ATR-FTIR and supported the intercalated composite formation. The thermal and mechanical stabilities of PLA matrices were also enhanced after OMMT and B incorporation. The lowest breaking strain value was recorded for PLA-OMMT/PBA composite compared to other B composites. The 100% and 50% extracts of the PLA-OMMT matrices showed modest cytotoxic effect on the human dermal fibroblasts (NHDF) on the second day culture that probably originated from TMOD. These results demonstrated that PLA-OMMT/B matrices, especially PBA including matrices, can be used as replaceable wound dressings that have limited interaction with cells but exhibit antibacterial activity and support the early stages of wound healing both morphologically and chemically.

A novel pH-responsive nanoniosomal emulsion for sustained release of curcumin from a chitosan-based nanocarrier: Emphasis on the concurrent improvement of loading, sustained release, and apoptosis induction.

Curcumin application as an anti-cancer drug is faced with several impediments. This study has developed a platform that facilitates the sustained release of curcumin, improves loading efficiency, and anti-cancer activity. Montmorillonite (MMT) nanoparticles were added to chitosan (CS)-agarose (Aga) hydrogel and then loaded with curcumin (Cur) to prepare a curcumin-loaded nanocomposite hydrogel. The loading capacity increased from 63% to 76% by adding MMT nanoparticles to a chitosan-agarose hydrogel. Loading the fabricated nanocomposite in the nanoniosomal emulsion resulted in sustained release of curcumin under acidic conditions. Release kinetics analysis showed diffusion and erosion are the dominant release mechanisms, indicating non-fickian (or anomalous) transport based on the Korsmeyer-Peppas model. FTIR spectra confirmed that all nanocomposite components were present in the fabricated nanocomposite. Besides, XRD results corroborated the amorphous structure of the prepared nanocomposite. Zeta potential results corroborated the stability of the fabricated nanocarrier. Cytotoxicity of the prepared CS-Aga-MMT-Cur on MCF-7 cells was comparable with that of curcumin-treated cells (p< 0.001). Moreover, the percentage of apoptotic cells increased due to the enhanced release profile resulting from the addition of MMT to the hydrogel and the incorporation of the fabricated nanocomposite into the nanoniosomal emulsion. To recapitulate, the current delivery platform improved loading, sustained release, and curcumin anti-cancer effect. Hence, this platform could be a potential candidate to mitigate cancer therapy restrictions with curcumin.

Biological applications of nanocomposite hydrogels prepared by gamma-radiation copolymerization of acrylic acid (AAc) onto plasticized starch (PLST)/montmorillonite clay (MMT)/chitosan (CS) blends

In this work, nanocomposite hydrogels were prepared by gamma-radiation copolymerization of acrylic acid (AAc) onto plasticized starch (PLST)/montmorillonite clay (MMT)/chitosan (CS) blends. The effect of irradiation dose and MMT nanoparticle contents on the gel fraction and water absorption characters of PAAc-co-(PLST/MMT/CS) hydrogels was investigated. In addition, the structure-property behavior of the nanocomposite hydrogels was characterized by FTIR spectroscopy, thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The study showed that the appropriate dose of gamma irradiation to achieve homogeneous nanocomposite hydrogels films and the highest absorption in water was 15 kGy, regardless of composition. The introduction of MMT up to 5-wt (%) improved the physical properties and enhanced the drug uptake-release characters. The effect of the nanocomposite hydrogels on skin wound healing were evaluated by rat models, taking sulfanilamide as a model drug. The profiles of rat skin after different time intervals up 21 days revealed that wounds treated with the copolymer hydrogels were healed faster which it may considered as a potential candidate for wound dressing materials.

Electroless Ni–B–MMT nanocomposite on magnesium alloy

ABSTRACT Ni–B and Montmorillonite (MMT)-containing Ni–B deposits were electrolessly plated on AM60B magnesium alloy. The Ni–B coating showed cauliflower-like micromorphology, microcrystalline-amorphous microstructure, and thickness of about 15 μm, which was not influenced by the inclusion of MMT nanoparticles. The surface roughness of the Ni–B coating changed from about 376 to 328 nm after the inclusion of MMT. The boron content of the electroless deposit was mildly increased after MMT inclusion. Thermal shock and porosity examinations revealed suitable adhesion and pore-free structure of the coatings, respectively. Polarization resistance of the Ni–B deposit in 3.5 wt-% sodium chloride was increased about 1.5 times by MMT inclusion. The corrosion current of the substrate was remarkably diminished from 46.89 to 0.12 µA cm−2 by the Ni–B plating. Also, MMT incorporation causes to further decrement of the corrosion current to about 0.03 µA cm−2.

Nanocomposites based on polyamide-6 and montmorillonite intercalated with polyvinylpyrrolidone

ABSTRACT The paper deals with the investigation results of nanocomposites based on polyamide-6 (PA6) and montmorillonite (MMT) intercalated by polyvinylpyrrolidone (PVP). Nanocomposites were obtained by mixing in the melt and the formic acid solution. The structure and presence of physical interaction between the nanocomposite components have been established using X-ray diffraction (XRD), differential thermal analysis (DTA), IR spectroscopy, and scanning electron microscopy (SEM). The presence of PVP in the structure of nanocomposites obtained from the solution was confirmed by IR spectroscopic analysis; the presence of layered MMT in the pyrolysis residue of nanocomposites was confirmed by diffractometry. SEM analysis confirmed the presence of layered MMT nanoparticles in the nanocomposite structure. It is shown that polyamide-based nanocomposites with a supramolecular structure different from PA6 are formed by precipitation from a solution; a crystalline composite is formed by mixing the components in the melt. It was found that nanocomposites obtained from the solution have a higher melt flow index (MFI) and lower softening temperature compared to those obtained in the melt. The formation of a homogeneous blend based on PA6/int-MMT nanocomposite with polypropylene (PP) was confirmed and the increase of thermo-physical characteristics of PP was determined.

Polyvalent Metal Ion Promoted Adsorption of DNA Oligonucleotides by Montmorillonite

Montmorillonite (MMT) is a two-dimensional (2D) clay material. Its abundance on the early earth has attracted studies for its role in prebiotic reactions, and adsorption of DNA to MMT is potentially important for understanding the origin of life. Although several possible models of DNA adsorption on MMT have been established, a consensus on the adsorption mechanism has yet to be formed, thereby a fundamental adsorption study is performed here. Adding up to 300 mM NaCl failed to promote DNA adsorption on MMT, Al2O3, or SiO2 nanoparticles. For polyvalent metals, DNA adsorption was achieved following the order Ce3+ > Cu2+ > Ni2+ > Zn2+. Among them, Ce3+ and Cu2+ inverted the surface charge of MMT to positive. In addition, using washing experiments, Cu2+- and Ce3+-mediated adsorption mainly depended on the DNA phosphate backbone, while Ni2+ and Zn2+ interacted with the backbone phosphate groups and adenine bases of DNA. Overall, these polyvalent metal ions promoted DNA adsorption via a cation bridge model. This research provides new insights into the surface interactions of MMT and DNA, which is conducive to future work on the interaction between clays and biopolymers.

Microstructural design for enhanced mechanical property and shape memory behavior of polyurethane nanocomposites: Role of carbon nanotube, montmorillonite, and their hybrid fillers

The recent rapid development of technology has demanded smart materials with tailoring a bridge between macro properties and sophisticated micro and nano characteristic. Principally, shape memory polymers (SMPs) will come to play as an indispensable part of numerous aspects of human activity. Nevertheless, the low mechanical strength and thermal conductivity of SMPs have primarily restricted their applications. To impart shape memory behaviour and mechanical properties, we fabricated a series of composites by a feasible and commercial melt-mixing method. Thus, a series of fast heat-actuated shape memory polymer composite with greatly enhanced stretch-ability, mechanical stiffness, dynamic-modulus, rheological qualities, recovery and fixity ratio was prepared by incorporating multi-walled carbon nanotubes (CNT), montmorillonite (MMT) and CNT:MMT hybrid into thermoplastic polyurethane (TPU). Noteworthy, CNT-based specimens exhibited superior mechanical properties than those of MMT-based samples, and interestingly, the hybrid composites featured a synergistic effect due to the sacrificial role of MMT nanoplatelets for adjusting the dispersion of CNT nanotubes. Microstructural observations indicated that the crystallization percentages of the composites were generally higher than that of pristine TPU; therefore, the shape-memory performance of the specimens improved notably in the case of the hybrid composites owing to creating more interfacial zone with CNT:MMT nanoparticles as compared to other simple composites. This study proved that the simultaneous incorporation of CNT and MMT nanoparticles not only granted outstanding mechanical properties, but also improved the overall shape memory behaviour of the composites by systematical localization of the nanoparticles without any functionalization or modification.

Removal of malachite green using carboxymethyl cellulose-g-polyacrylamide/montmorillonite nanocomposite hydrogel

In this study, carboxymethyl cellulose based graft poly(acrylamide) hydrogel (CMC-g-P(AAm)) and its nanocomposite with montmorillonite (CMC-g-P(AAm)/MMT) were produced by the free radical method and it was used to malachite green (MG) dye removal from aqueous solution. The properties and characterization of the adsorbents were investigated using FTIR, SEM, TGA, and XRD analyzes, and the results showed that MMT nanoparticles were successfully distributed in the hydrogel system. MMT nanoparticles were loaded into the hydrogel system with different weight percentages and the maximum adsorption efficiency of MG dye was determined at 10 wt% MMT. Also, the effect of temperature, contact time, initial concentration of MG dye and initial pH on the adsorption efficiency of MG dye was studied in a batch. Equilibrium behavior investigation of the adsorption process showed that the equilibrium data determined are in good agreement with the Langmuir isotherm model and the monolayer surfaces play an effective role in the adsorption process. The maximum monolayer adsorption capacity (qmax) determined using the Langmuir isotherm model for CMC-g-P(AAm) and CMC-g-P(AAm)/MMT were determined to be 158.1 mg/g and 172.4 mg/g, respectively. Also, the kinetic study showed that the pseudo-second- order kinetic model is more capable of describing the kinetic behavior of the process than other models. Also, the α parameter values for the MG dye adsorption process using CMC-g-P(AAm) and CMC-g-P(AAm)/MMT were determined to be 0.6337 mg/g·min and 31.04 mg/g·min, respectively. This indicates that the produced composite has a high adsorption value. Gibbs free energy (ΔG°) was negative for the adsorption processes in the range of 25–50 °C, indicating that the process was spontaneous. In addition, the enthalpy parameter (ΔH°) was determined for the adsorption process using CMC-g-P(AAm) and CMC-g-P(AAm)/MMT nanocomposite hydrogels at 39.859 KJ/mol and 74.736 KJ/mol, respectively. Positive ΔH° indicates that the process is endothermic in the range of 25–50 °C using both adsorbents. Also, the concentrations effect of Na+ and K+ ions on adsorption efficiency was investigated and it was concluded that the efficiency of the adsorption process decreased with the increase of ions concentration. Adsorption efficiency decrease can be due to the occupation of active sites and repulsive electrostatic interactions at the adsorbent surface with the MG dye molecule.

Studying the Mechanical and Thermal Properties of Polymer Nanocomposites Reinforced with Montmorillonite Nanoparticles Using Micromechanics Method

In this study, the mechanical and thermal behavior of the nano-reinforced polymer composite reinforced by Montmorillonite (MMT) nanoparticles is investigated. Due to low cost of computations, the 3D representative volume elements (RVE) method is utilized using ABAQUS finite element commercial software. Low density poly ethylene (LDPE) and MMT are used as matrix and nanoparticle material, respectively. By using various geometric shapes and weight fractions of nanoparticle, the mechanical and thermal properties such as Young’s modulus, shear modulus, heat expansion coefficient and heat transfer coefficient are studied. Due to addressing the properties of interfacial zone between the matrix and nanoparticle, finite element modeling is conducted in two ways, namely, perfect bonding and cohesive zone. The results are validated by comparing with experimental results reported in literature and a reasonable agreement was observed. The prediction function for Young’s modulus is presented by employing Genetic Algorithm (GA) method. Also, Kerner and Paul approaches as theoretical models are used to calculate the Young’s modulus. It was finally concluded that the magnitude of the Young’s and shear modules increase by adding MMT nanoparticles. Furthermore, increment of MMT nanoparticles to polymer matrix nanocomposite decrease the heat expansion and heat transfer coefficients.

Novel Poly(vinyl alcohol)/Clay Nanocomposite Film Prepared by the Heterogeneous Saponification of Poly(vinyl acetate)/Clay Nanocomposite Film

A novel PVA/clay (MMT) film is prepared for the first time based on the saponification of the PVAc/MMT film in the presence of heterogeneous conditions. With the help of optical microscopy, the characteristics and surface morphology of the saponified PVA/MMT film is confirmed. It is found to contain black MMT nanoparticles in PVAc films as the content of MMT increased. According to atomic force microscopy results, PVAc/MMT films shows unexpected surface roughness owing to the slow progress of the saponification reaction in the presence of MMT contents in the PVAc matrix. The thermal stability of the PVA/MMT film is measured using thermal gravimetric analyses. The results indicate that thermal stability increases significantly when the MMT concentration increases. The entire structure of the PVA/MMT nanocomposite has been elucidated using XRD. To prove the differences between the PVAc/MMT and the PVA/MMT films, XRD measurements and Fourier transform Infrared spectroscopy analyses are utilized.

Bio nanocomposites based on cationic starch reinforced with montmorillonite and cellulose nanocrystals: Fundamental properties and biodegradability study

The bio-nanocomposites of cationic starch (CS)/montmorillonite (MMT)/nanocrystalline cellulose (NCC) were produced by solution casting method. The effects of NCC and MMT nanoparticles on optical, barrier and mechanical properties of CS films were investigated. X-ray diffraction results confirmed the partly intercalated and partly exfoliated structure of CS/MMT/NCC films. The FTIR test showed the forming of new hydrogen bonds between the CS hydroxyl groups and nanoparticles. FESEM analysis proved that the dispersion of NCC and MMT in the CS matrix is homogenous. The optical clarity of CS based films was almost unaffected in presence of MMT and NCC. The ternary nanocomposites with 5 wt% NCC and MMT showed the best improvements in the properties. The tensile strength and the tensile modulus of nanocomposites increased up to 61% and 73% respectively, compared to the pure CS film. The nanocomposites demonstrated highest disintegrability rate and good reduction in water vapor and oxygen permeability with addition of NCC.

Influence of interfacial interaction on the mechanical properties of amorphous PE/MMT nanocomposites

We carried out molecular dynamics simulations to examine the structural, interfacial, and mechanical properties of amorphous polyethylene/montmorillonite (PE/MMT) nanocomposites loaded with 0 wt. %, 3.3 wt. %, 4.0 wt. %, and 5.1 wt. % of modified organic MMT (O-MMT). The MMT nanoparticles were simulated in two stages: first treated with octadecyl trimethyl ammonium chloride and then doped in amorphous PE. The effects of the O-MMT content on the microstructure parameters (interaction energy, free volume, and interfacial thickness) and macroscopic mechanical properties (Young’s modulus, bulk modulus, and shear modulus) were analyzed. A strong correlation between mechanical properties and interfacial thickness was observed by analyzing the obtained data from simulation, and we verified them through experiments.

The role of Na-montmorillonite/cobalt ferrite nanoparticles in the corrosion of epoxy coated AA 3105 aluminum alloy

The present findings support the significance of epoxy nanocomposites in the protection of AA3105 aluminum by Na- montmorillonite (Na-MMT)/CoFe2O4 nanopowder. In this work, crystalline CoFe2O4 nanoparticles and Na- MMT/CoFe2O4 nanopowder were synthesized by using coprecipitation method and doping method, respectively. The structural properties of CoFe2O4, Na- MMT nanoparticles and Na-MMT/CoFe2O4 nanopowder were investigated by using X-ray diffraction (XRD) technique, ultraviolet-visible spectroscopy and Fourier transform infrared (FTIR) spectroscopy Therefore, the epoxy nanocomposite coatings, containing various amounts of Na-MMT/ CoFe2O4 nanoparticles were coated on the surface of an AA3105 aluminum specimen. The effects of addition of nanopowder on the resistance of the coating against corrosion of AA3105 aluminum in 3.5% NaCl solution were studied by electrochemical techniques (potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)). Impedance and potentiodynamic polarization testing results, evidenced the improvement of the protection feature of the coatings against corrosion in the presence of the formulations with superior anticorrosion of EC80. The morphology and composition of the films were probed by FE- SEM and EDS.

Mechanical Properties of Polypropylene (PP) – Montmorillonite (MMT) Nanocomposites for Pre-Fabricated Vertical Drain (PVD) Application

Polypropylene (PP) – montmorillonite (MMT) blends were prepared by melt-mixing method followed by injection molding method. The optimum process melt-temperature was set at 1950C, the injection speed of 15cc/s, injection pressure of 30MPa and cooling time of 20 sec. was used for the sample preparation. Investigation shows, addition of MMT nanoparticles have improved the mechanical properties. The tensile test and impact test were conducted at room temperature and atmospheric pressure. The tensile modulus and yield strength improved with increasing MMT content, however, elongation at break was reduced as the MMT content was increased from 2wt% to 8wt%. The Izod impact strength is also affected by the addition of MMT content. Nanocomposites based on PP containing 8wt% of MMT showed higher impact strength than the other compositions and Neat PP (control). The influence of MMT content on impact strength increased with MMT content which is a significant result required for pre-fabricated vertical drain (PVD). Further investigations are required to study the mechanical properties of the PVD using PP – MMT nanocomposites to replace the existing material (PP).

Effect of ZnO nanoparticles on the mechanical, barrier and optical properties of thermoplastic cationic starch/montmorillonite biodegradable films

In this study, various amounts of nanoclay montmorillonite (MMT) and ZnO nanopowders were used to analyze the properties of biodegradable nanocomposites of cationic starch (CS). Nanocomposites are produced by solvent casting method. The structure of CS-MMT nanocomposite films that contain 3% montmorillonite was exfoliated and was proved by XRD test. New hydrogen bonds were successfully formed between the CS hydroxyl groups and nanofillers and this was proved by FTIR test. The water vapor permeability and the UV light transmittance of the nanocomposites reduced after the contents of MMT and ZnO increased. ∆E and opacity of the nanocomposites enhanced after the amount of ZnO increased. Tensile strength (TS) of nanocomposites increased after the incorporation of ZnO and MMT nanoparticles although the elongation at break was diminished. Results showed that the 3 and 0.7 wt% amounts of montmorillonite and ZnO nanopowders were sufficient in order to acquire a well-moderated mechanical behavior in plastic and elastic regions, and they also cause good improvements in barrier and optical properties.

Dimensional impact of nanofillers on the micromorphology and rheology of PP/PS composites under continuous elongation flow

Three kinds of nanoscaled fillers, namely, zero‐dimensional nanosphere titanium dioxide (TiO2), one‐dimensional multi‐walled carbon nanotubes (MWCNTs), and two‐dimensional nanoplate montmorillonite (MMT), were added to the representative polypropylene (PP)/polystyrene (PS) blends by eccentric rotor extruder based on elongation flow. Confirmed from images of transmission electron microscopy and scanning electron microscopy, three kinds of nanofillers were uniformly dispersed in the blends under continuous elongation flow and the presence of nanofillers led to a marked decrease of dispersed phase size of PS. The dispersed PS particles were turned into spherical status in matrix with the addition of TiO2 and MWCNTs and showed irregular shapes in the composites with MMT. The PS particle size of PP/PS/MMT was decreased most obviously, dropping from 4.44 to 1.42 μm, which resulted in obvious improvements in storage modulus and complex viscosity of the composites. The results of wide‐angle X‐ray diffraction and dynamic mechanical analysis indicated that MMT nanoparticles were highly intercalated in PP/PS blends, which obviously improved compatibility of PP and PS. Our work certified that the two‐dimensional nanoplate MMT are better compatibilizers compared with the zero‐dimensional nanosphere TiO2 and one‐dimensional MWCNTs for PP/PS composites.