Organic Montmorillonite Research Articles

Study on Rheological Properties of Waste Cooking Oil and Organic Montmorillonite Composite Recycled Asphalt

Pre-treated waste cooking oil (WCO) and organic montmorillonite (OMMT) were employed for the recycling of aged asphalt, which resulted in the improvement of the design of WCO asphalt rejuvenators and the enhancement of high-temperature performance of WCO-recycled asphalt. The effect of the rejuvenator and the properties of recycled asphalt were evaluated by viscosity, dynamic shear rheometer (DSR), bending beam rheometer (BBR) and scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC) tests. The results indicated that aged asphalt could be obviously softened and restored to the level of original asphalt by adding 6% WCO. However, the high-temperature properties of recycled asphalt would be declined by adding too large a dose of WCO rejuvenator. The high-temperature performance of recycled asphalt was significantly improved by the WCO-OMMT complex rejuvenator, and the viscosity and rutting factor of recycled asphalt were increased. Light components of aged asphalt could be supplemented by WCO of the complex rejuvenator. The volatilization of small molecules could be slowed down by the peel structure formed by OMMT and small molecules of the asphalt, which resulted in the proportion of small molecular substances (SMS) being increased by 4% and improvement of the colloidal structure of aged asphalt. The high-temperature and low-temperature performance of recycled asphalt can be improved concurrently by the combination of 6% WCO and 1% OMMT, and this was evidenced by the fact that the high-temperature and low-temperature PG were all upgraded by one level.

Impact resistance of polyurethane elastomer enhanced by organic montmorillonite with interlayer anchored polymer chains

AbstractThe development of materials with excellent impact resistance is essential for safety protection. Polyurethane elastomer (PUE) is widely used in impact protection; however, it has low dynamic compressive strength and poor energy absorption efficiency under high‐speed impact, limiting its in‐depth application in the protection field. Herein, an organic montmorillonite (MMT) with interlayer anchored polymer chains, named M@NH3+, was synthesized via the dual modification of MMT involving surface grafting and cation intercalation by macromolecular amino silane, which was used to enhance the impact resistance of PUE. Based on the uniform dispersion of M@NH3+ within the PUE matrix, the strong bonding at the polymer‐filler interface and the synergistic action between M@NH3+ lamellae, PUE‐M@NH3+ composite exhibited excellent mechanical properties and energy absorption capacity. Compared with pure PUE, the elastic modulus (+98.3%), static compressive strength (+37.0%), dynamic compressive strength (+35.4%) and impact energy absorption (+50.8%) of PUE‐2wt%M@NH3+ were significantly improved, which shows that it has potential applications in the field of high‐speed impact protection.Highlights Organic MMT with interlayer anchored polymer chains was prepared. The large interlayer spacing of M@NH3+ facilitates its dispersion within the matrix. The interconnected M@NH3+ lamellae can collaboratively disperse impact stress. The impact energy absorption of PUE composite has been remarkably improved.

Organic montmorillonite modified polyethylene oxide based polymer electrolyte for dendrite-free flexible solid-state lithium metal batteries

Polyethylene oxide (PEO) based solid-state electrolytes are known for the low manufacturing cost and excellent processability, but their practical application is paved with thorns including the inferior ionic conductivity, low Li+ transfer number and insufficient Li dendrite blocking ability. Herein, we propose organic montmorillonite (OMMT) with expanded layer spacing (1.97 nm) as versatile fillers to construct PEO-OMMT electrolyte, in which OMMT not only increases Li+ transfer number (0.56) and ionic conductivity (7.15 × 10−4 S cm−1), providing fast ionic transport channels, but also endows PEO with high mechanical strength, resulting remarkable Li dendrite blocking ability (>2100 h). Additionally, the high dielectric constant and Lewis-rich polar sites of OMMT facilitate the dissociation of lithium salts and the rapid formation of LiF and Li3N-rich solid electrolyte interface layers. Impressively, the LiFePO4|PEO-OMMT|Li cell shows a high initial capacity (154.4 mAh g−1 at 0.5C) with ultralong cycling lifespan (>1200 cycles). Similarly, the LiNi0.83Mn0.05Co0.12O2|PEO-OMMT|Li cell retains a high discharge capacity of 151.5 mAh g−1 after 100 cycles at 0.2C. This work highlights the indelible contributions of OMMT functionalized fillers in improving the interfacial stability of PEO based solid-state electrolytes, paving a feasible avenue for the practical application of solid-state lithium metal batteries.

Improving the performance of CFRP-reinforced concrete cylinders in sulfate-laden environment through nanoclay modification of epoxy resin

The durability of epoxy-concrete interface is a crucial factor for practical application of externally bonded fiber-reinforced polymer (FRP) retrofit systems, particularly when the strengthened structure is subjected to severe environmental conditions. Given the demonstrated potential of nanoclays in enhancing engineering performance of polymers, this work assesses the beneficial effect of organic montmorillonite (OMMT) nano-modification of epoxy resin on the axial compressive properties of FRP-reinforced concrete under a 10 wt% sodium sulfate wet/dry (W/D) cycling environment. Three types of concrete samples were fabricated and tested: plain concrete cylinders, CFRP-reinforced concrete cylinders using unmodified vs. OMMT-modified epoxy resin as the adhesive, respectively. The optimal dosage of OMMT was determined to be 2 wt% through tensile and lap shear tests, as well as microscopic characterization of the fractured cross-section of the molded resin samples. This optimal dosage of OMMT allows the epoxy adhesive to achieve the highest values in the tensile strength (90.4 MPa), lap shear strength (80.0 MPa), Tg (280.5°C) and water contact angle (115.1°). In the fracture section of epoxy resin with a 2 wt% OMMT, multiple microcracks developed and the OMMT nanoplatelets were well dispersed in the epoxy matrix. The laboratory testing program explored various W/D cycle periods. The experimental results indicate that the OMMT-modified epoxy resin significantly improved the mechanical properties and deformation resistance, altered the failure mode, and effectively delayed the strength degradation of the protected concrete. After 150 W/D cycling days, the OMMT-modified CFRP-confined concrete samples maintained their ductility coefficient and axial compressive strength at 3.58 and 123.5 MPa, respectively, 12.6 % and 9.1 % better than the common CFRP-confined samples. Combining these results with the residual axial compressive strength ratio, we propose an improved design model for calculating the axial compressive strength of CFRP-retrofitted concrete structures in sulfate-laden environments. This study demonstrates the beneficial role of OMMT in enhancing the epoxy adhesive and provides insights into the reinforcement of concrete structures by externally bonded CFRP in sulfate-rich environments.

Emission reduction effect of eco-friendly asphalt modified with isocyanate-nanoclay composites

The environmental and health issues associated with the generation of fumes during hot mix asphalt used in road construction necessitate the exploration of cleaner production methods. This study investigated the viability of utilizing isocyanate-nanoclay composites as modifiers for eco-friendly modified asphalt. The composite modified asphalt samples were prepared by adding isocyanate (isophorone diisocyanate, IPDI) and nanoclay (organic montmorillonite, OMMT or attapulgite, ATT) to the base asphalt at varying contents. A device for generating and collecting asphalt fumes was developed. The impact of modifier dosage on fume emission reduction was assessed quantitatively and qualitatively using ultraviolet–visible spectrophotometry and gas chromatography-mass spectrometry, yielding the optimal ratio of composite modifiers. The fume emission reduction mechanism of the modifiers was elucidated by analyzing changes in distribution, functional group composition and micromolecular spacing of asphalt using fluorescence microscopy, fourier-transform infrared reflection, and X-ray diffraction. Results revealed that the intercalation effect between nanoclay and asphalt, combined with chemical reactions between isocyanates and functional groups of nanoclay/asphalt components, effectively impeded the escape of fume molecules. Modified asphalt with 3% ATT+3% IPDI achieved an impressive fume emission reduction rate of 44.67% and enhanced basic performance of base asphalt. The findings contribute to the development of cleaner production methods for hot mix asphalt, thus paving the way for sustainable and safer construction practices in the future.

Nonlinear Conductivity and Thermal Stability of Anti-Corona Epoxy Resin Nanocomposites.

The long-term operation of motors induces substantial alterations in the surface conductivity and nonlinear coefficient of anti-corona paint, diminishing its efficacy and jeopardizing the longevity of large motors. Hence, the development of high-performance anti-corona paint holds paramount importance in ensuring motor safety. In this study, we integrate two nano-fillers, namely silicon carbide (SiC) and organic montmorillonite (O-MMT), into a composite matrix comprising micron silicon carbide and epoxy resin (SiC/EP). Subsequently, three distinct types of anti-corona paint are formulated: SiC/EP, Nano-SiC/EP, and O-MMT/SiC/EP. Remarkably, O-MMT/SiC/EP exhibits a glass transition temperature about 25 °C higher than that of SiC/EP, underscoring its superior thermal properties. Moreover, the introduction of nano-fillers markedly augments the surface conductivity of the anti-corona paint. Aging tests, conducted across varying temperatures, unveil a notable reduction in the fluctuation range of surface conductivity post-aging. Initially, the nonlinear coefficients exhibit a declining trend, succeeded by an ascending trajectory. The O-MMT/SiC/EP composite displays a maximum nonlinearity coefficient of 1.465 and a minimum of 1.382. Furthermore, the incorporation of nanofillers amplifies the dielectric thermal stability of epoxy resin composites, with O-MMT/SiC/EP showcasing the pinnacle of thermal endurance. Overall, our findings elucidate the efficacy of nano-fillers in enhancing the performance and longevity of anti-corona paint, particularly highlighting the exceptional attributes of the O-MMT/SiC/EP composite in bolstering motor safety through improved thermal stability and electrical properties.

Degradation of the emerging brominated flame retardant tetrabromobisphenol S using organo-montmorillonite supported nanoscale zero-valent iron.

The widespread occurrence of emerging brominated flame retardant tetrabromobisphenol S (TBBPS) has become a major environmental concern. In this study, a nanoscale zero-valent iron (nZVI) impregnated organic montmorillonite composite (nZVI-OMT) was successfully prepared and utilized to degrade TBBPS in aqueous solution. The results show that the nZVI-OMT composite was very stable and reusable as the nZVI was well dispersed on the organic montmorillonite. Organic montmorillonite clay layers provide a strong support, facilitate well dispersion of the nZVI chains, and accelerate the overall TBBPS transformation with a degradation rate constant 5.5 times higher than that of the original nZVI. Four major intermediates, including tribromobisphenol S (tri-BBPS), dibromobisphenol S (di-BBPS), bromobisphenol S (BBPS), and bisphenol S (BPS), were detected by high-resolution mass spectrometry (HRMS), indicating sequential reductive debromination of TBBPS mediated by nZVI-OMT. The effective elimination of acute ecotoxicity predicted by toxicity analysis also suggests that the debromination process is a safe and viable option for the treatment of TBBPS. Our results have shown for the first time that TBBPS can be rapidly degraded by an nZVI-OMT composite, expanding the potential use of clay-supported nZVI composites as an environmentally friendly material for wastewater treatment and groundwater remediation.

Preparation and Corrosion Resistance of OMMT/EP Composite Coatings in Sulfur-Containing Sodium Aluminate Solution

Organic montmorillonite (OMMT) was prepared from Na-montmorillonite (MMT) by Hexadecylamine (HDA) modification. The composite material has good smoothness, acidity, and salt resistance. OMMT was characterized using small-angle X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and a video optical contact angle measuring instrument. The results showed that the layer spacing was enlarged from 1.44 nm to 2.87 nm after the modification, and the hydrophobicity performance was greatly improved. The organic modification of MMT was successful. The surface morphology, roughness, and anticorrosion properties of the organic montmorillonite/epoxy (OMMT/EP) composite coating were investigated and compared with those of the epoxy (EP) coating. The OMMT/EP composite coating had a flatter surface than the EP coating. The roughness was reduced from 65.5 nm to 10.3 nm. The electrochemical impedance spectroscopy showed that the composite coating’s thickness positively affected its anticorrosion performance, the corrosion current density (Icorr) decreased with the increase in thickness, and its maximum impedance was much larger than that of EP coating. The protection efficiency of the OMMT/EP composite coating was 77.90%, which is a significant improvement over the EP’s 31.27%. In addition, the corrosion resistance of the composite coating gradually decreased with increasing immersion time, but the change was insignificant.

Research progress on the flame retardation and modification of polypropylene by montmorillonite

Montmorillonite can be used to achieve nano-dispersion level by forming peel or intercalation structure in polypropylene body, so as to improve the mechanical properties of the material. In addition, montmorillonite plays the role of nucleating agent during the crystallization of polypropylene, which improves the crystallization efficiency of polypropylene. After the organic modification of montmorillonite, the spacing between crystal surfaces can be enlarged to form organic montmorillonite, which makes the molecular chains of polypropylene more easily dispersed to the interlayer of organic montmorillonite, forming a dense surface layer in the process of thermal decomposition, so as to improve the thermal stability of polypropylene and enhance the flame retardant property of polypropylene. Many previous studies have shown that montmorillonite plays a significant role in improving the mechanical strength and crystallization effect of polypropylene, as well as the flame retardant properties of nanocomposites.

SiO2 aerogel coating with organic montmorillonite compounded with flame retardants: A strategy for design of a multifunctional thermal barrier coating

To improve the thermal barrier properties of epoxy resin coatings, a composite waterborne aerogel multifunctional coating that possesses both mechanical properties and controllable barrier ability was prepared in this study. This coating incorporates granular silica aerogel, organic montmorillonite, and two flame retardants: aluminum hydroxide (ATH) and magnesium hydroxide (MH). The results showed that montmorillonite, modified with stearyl trimethyl ammonium bromide (STAB), exhibited antisymmetric and symmetric stretching vibrational infrared spectral absorption peaks of –CH3, –CH2, characteristic of the long-chain alkane quaternary ammonium salt. This indicated that the quaternary ammonium salt was intercalated into the montmorillonite interlayer, enhancing the surface lamellae. The coating effectively absorbed energy when stressed, resulting in a strength increase of 146.3%. Incorporating high porosity silica aerogel significantly improved the barrier behavior of the composite coating, enabling controlled thermal insulation and excellent corrosion resistance. The coating reduced heat transfer paths and effectively impeded heat transfer, maintaining a high corrosion inhibition efficiency (99.9%) in a 3.5% NaCl solution. Additionally, the individual actions of the two flame retardants led to highly effective flame retardant properties, with the total heat release rate (THR) reduced by about 43.5% and the total smoke production (TSP) by 40.1%.

Performance investigation of phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT) compound-modified bituminous mixture

ABSTRACT Composite modification has proven to be an effective strategy in addressing the insufficient performance associated with single-modified bituminous mixture. This research aims to thoroughly investigate the performance of the compound-modified bituminous mixture incorporation phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT). The performance investigations of the bituminous mixture were conducted through the Marshall stability test, dynamic stability test, indirect tensile test, immersion Marshall test, freeze–thaw splitting test, indirect tensile fatigue test and long-term aging test. The test results indicated that OMMT plays a crucial role in advancing thermal storage stability and compatibility between PF and bitumen. Importantly, the optimal dosage of OMMT was determined not to exceed 5%. The 3%PF+5%OMMT bituminous mixture demonstrated excellent rutting and cracking resistance, superior water stability and anti-fatigue capabilities. Furthermore, the 2%PF+5%OMMT and 3%PF+5%OMMT bituminous mixtures exhibited superior anti-aging abilities. In consideration of laboratory performance and bitumen compatibility, the combination of 3%PF+5%OMMT can be utilised to enhance the bituminous mixture performance. The results of single-factor analysis of variance indicated that PF and OMMT had significantly impact on the bituminous mixture performance. Notably, the influence of PF/OMMT dosage on the cracking resistance, water stability and anti-aging ability requiring attention when considering them as bitumen modifiers.

Oily bioorganoclays in drilling fluids: Micro and macroscopic properties

The application of organoclays as an additive to improve the performance of oil-based drilling fluids has long been a subject of research. In this work, montmorillonite containing zinc cations was modified by lecithin to synthesize organic montmorillonite (ZnOMt), which was then dispersed in vegetable and mineral oils for the preparation of oil-based drilling fluids. Their viscoelastic properties were evaluated and linked to ZnOMt microstructure information obtained by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). The nature of the oil used and the heating temperature are key parameters influencing the performance of oil-based drilling fluid. The favorable properties of vegetable oil-based drilling fluids containing organoclays provide great potential for their application in drilling engineering.

Multi-scale study of compound modified asphalt materials by waste cooking oil and organic montmorillonite on high temperature performance

Asphalt binder as a by-product of petroleum is a finite resource. Hence, finding an alternative material for asphalt binder is a potential topic in the road engineering. Performance of compound-modified asphalt material at high temperatures, by waste cooking oil (WCO) and organic montmorillonite (OMMT) was investigated in this study, and the multi-scale correlation evaluation was conducted. The findings revealed that the bio-oil significantly reduces the barrier to rutting of asphalt materials within multi-scales, and rutting resistance was reduced with increased content. High-temperature performance can be regained or even better than that of base asphalt materials when WCO Bio-oil: OMMT is 1:1, and OMMT can compensate for the loss of high-temperature performance. Besides, the multi-scale correlation analysis shows that the Jnr3.2 index of OMMT composite modified bio-asphalt mastic, asphalt mixtures' resistance to rutting at high temperatures can be predicted using their short-term aging condition.

Rheological properties of SBS-modified asphalt containing aluminum hydroxide and organic montmorillonite

The composite flame retardant composed of aluminum hydroxide (ATH) and organic montmorillonite (OMMT) is of potential application value in the tunnel asphalt pavement. To investigate the effect of ATH and OMMT on the rheological properties of SBS modified asphalt at high and low temperatures. In this study, the composite ATH/OMMT/SBS modified asphalt was subjected to multiple stress creep recovery (MSCR), linear amplitude sweep test (LAS), and Bending beam rheometer (BBR) experiments. Analysis of high and low temperature rheological properties and fatigue properties of composite ATH/OMMT/SBS modified asphalt under the conditions of single incorporation and composite modification. The findings of the tests suggest that ATH can significantly improve the fatigue life but has adverse impact on the creep recovery property of asphalt materials, OMMT has a significant improvement effect on the low-temperature performance, however, the detrimental effect of OMMT on fatigue performance is greater than the improvement of ATH. The research results provide a reference for the practical application of flame retardants.

Efficient degradation of hexabromocyclododecane using montmorillonite supported nano-zero-valent iron and Citrobacter sp. Y3

The coupling of modified nanoscale zero-valent iron (nZVI) with organohalide-degrading bacteria provides a promising solution for the remediation of hexabromocyclododecane (HBCD)-contaminated environments. However, the interactions between modified nZVI and dehalogenase bacteria are intricate, and the mechanisms of synergistic action and electron transfer are not clear, and requires further specific investigation. In this study, HBCD was used as a model pollutant, and stable isotope analysis revealed that organic montmorillonite (OMt)-supported nZVI coupled with the degrading bacterial strain Citrobacter sp. Y3 (nZVI/OMt–Y3) can use [13C]HBCD as the sole carbon source and degrade or even mineralise it into 13CO2 with a maximum conversion rate of 100% within approximately 5 days. Analysis of the intermediates showed that the degradation of HBCD mainly involves three different pathways: dehydrobromination, hydroxylation, and debromination. The proteomics results showed that nZVI introduction promoted the transport of electrons and debromination. Combining the results from XPS, FTIR, and Raman spectroscopy with the analysis results of proteinomics and biodegradation products, we verified the process of electron transport and proposed a metabolic mechanism of HBCD degradation by the nZVI/OMt–Y3. Moreover, this study provides insightful avenues and models for the further remediation of HBCD and other similar pollutants in the environment.

Mechanism of a Warm-Mix Agent and Its Effects on the Rheological Properties and Thermal Stability of Aluminum Hydroxide and Organic Montmorillonite Composite Flame-Retardant Asphalt

Mechanism of a Warm-Mix Agent and Its Effects on the Rheological Properties and Thermal Stability of Aluminum Hydroxide and Organic Montmorillonite Composite Flame-Retardant Asphalt

Design of novel Polylactide composite films with improved gas barrier and mechanical properties using epoxy chain extender‐grafted organic montmorillonite

AbstractPolylactic acid (PLA) packaging materials are useful, safe, and degradable in the natural environment, and hence, have attracted considerable interest. In particular, the barrier properties of PLA are the focus of current research. In this study, organic montmorillonite (OMMT) modified with an epoxy chain extender (CE) was prepared as a barrier functional additive for PLA and PLA alloy materials. The effects of the CE‐OMMT on the properties of PLA and PLA/PHA (polyhydroxyalkanoates) composites were investigated. The CE‐OMMT was characterized using Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), and thermogravimetry (TG). The results showed that the CE‐OMMT was successfully synthesized, and that the addition of the CE did not change the crystal structure of OMMT. The morphology and microstructure of the PLA/CE‐OMMT and PLA/PHA/CE‐OMMT composites were characterized using XRD and transmission electron microscopy (TEM). The dispersion of the CE‐OMMT in the PLA and PLA/PHA composite films was significantly enhanced. XRD analysis showed that OMMT intercalated well into the matrix. The rheological, barrier, and mechanical properties of the PLA nanocomposite films were systematically studied. The results showed that the CE‐OMMT enhanced the mechanical and barrier properties of the composite films. Compared with neat PLA, the elongation at break of the PLA/CE‐OMMT and PLA/PHA/CE‐OMMT composite films with the addition of 3% CE‐OMMT increased by 449% and 788.4%, the oxygen permeability decreased by 57.74% and 59%, and the water vapor permeability decreased by 44.79% and 53.25%, respectively. Therefore, the modified PLA composite film is a promising substitute for packaging applications.

Effect of halloysite nanotubes (HNTs) and organic montmorillonite (OMMT) on the performance and mechanism of flame retardant-modified asphalt

Effect of halloysite nanotubes (HNTs) and organic montmorillonite (OMMT) on the performance and mechanism of flame retardant-modified asphalt

Emission of Volatile Organic Compounds in Crumb Rubber Modified Bitumen and Its Inhibition by Using Montmorillonite Nanoclay

Bitumen emits a large amount of volatile organic compounds (VOCs) during the production and construction of asphalt mixture, which can cause both environmental hazards and health risks. In this study, a setup was designed to collect the VOCs released by base and crumb rubber-modified bitumen (CRMB) binders and their composition was characterized by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Next, organic montmorillonite (Mt) nanoclay was added into CRMB binder and its inhibiting effect on the VOCs emission of the binder was investigated. Finally, the VOCs emission models for the CRMB and Mt-modified CRMB (Mt-CRMB) binders were established according to reasonable assumptions. The results indicated that the VOCs emission of CRMB binder was 3.2 times larger than that of the base binder. Due to its intercalated structure, the nanoclay can reduce the VOCs emission of CRMB binder by 30.6%. Especially, its inhibition effects on alkanes, olefins, and aromatic hydrocarbons were more significant. After finite element verification, the established model based on the Fick's second law can describe the emission behavior of CRMB and Mt-CRMB binders well. Overall, the Mt nanoclay can be used as an effective modifier to inhibit the VOCs emission of CRMB binder.

Development of organic-inorganic hybrid antimicrobial materials by mechanical force and application for active packaging

The loading and delivery of nanomaterials have attracted considerable interest. In this study, the organic-inorganic hybrid antimicrobial materials of clove essential oil (CEO) intercalated organic montmorillonite (MMT) were prepared using a facile and novel cryogenic ball milling technology and characterized. Fourier transform infrared spectroscopy, powder X-ray diffraction, and transmission electron micrograph analysis confirmed the successful preparation of the hybrid antimicrobial materials, and thermogravimetric analysis further demonstrated the thermal stability. In a novel application, hybrid antimicrobial materials were extruded with thermoplastic starch (TPS), polylactic acid (PLA), and poly (butylene adipate-co-terephthalate) (PBAT) to prepare active packaging films. The film release experiments showed that the CEO in the film, containing hybrid antimicrobial materials, was in a sustained release state, and its equilibrium release was higher than that of other films. The prepared films were used to preserve fresh abalone （Haliotis discus hannai Ino）, physicochemical changes and microbiological counts were determined. The results showed that the shelf life of fresh abalone packed in films containing hybrid antimicrobial materials was extended by 3–5 days, indicating that cryogenic ball milling is a simple and effective method for preparing organic-inorganic hybrid antimicrobial materials for active packaging.