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Intending to provide efficient and compact wastewater remediation, the present work is exploiting and introducing a novel composite prepared from porous starch aerogel (PSA) and organically modified Ca-montmorillonite (OMMT) for the removal of dyes from aqueous samples. First, potato starch components were used as a hydrolysis precursor to obtain PSA. The organoclay samples were prepared by co-intercalation of octadecylamine (ODA) into Ca-MMT using a low-temperature melting procedure. Composites with different starch-to-organoclay ratios of 10:1, 1:1, and 1:10 were then prepared by a blending process in distilled water and used for methyl orange (MO) uptake. The removal of methyl orange dyes increased with the amount of organoclay in the PSA matrix. Characterization revealed that organoclay synergy improved the PSA surface chemistry, while an important improvement in textural properties and thermal stability was also observed. The composite's efficiency was demonstrated by high removal capabilities towards MO in most experimental runs, with a maximum adsorption capacity beyond 344.7 mg/g. The fitting result showed that MO adsorption follows a monolayer adsorption model, and chemisorption was the rate-controlling step. Nonetheless, this study proved the great potential of PSA/OMMT in dyeing wastewater treatment. Furthermore, starch modification is proven as an effective approach to enhancing the performance of starch-derived adsorbents. [ABSTRACT FROM AUTHOR]

Composites based on high-pressure polyethylene and ethylene–vinyl acetate copolymer containing a sepiolite clay powder with a chain-layered structure are studied, and an analysis of their physical and mechanical properties is carried out. No organomodification and compatibilization are required in the case of using sepiolite. It is shown that composite materials with the addition of sepiolite are superior with respect to a series of characteristics to composite materials containing conventionally applied layered clay powders. [ABSTRACT FROM AUTHOR]

Research on bionanocomposites has been developed, while its application as food packaging is still being explored. They are usually made from natural polymers such as cellulose acetate, chitosan (CS), and polyvinyl alcohol. Bionanocomposite materials can replace traditional non-biodegradable plastic packaging materials, enabling them to use new, high-performance, lightweight, and environmentally friendly composite materials. However, this natural polymer has a weakness in mechanical properties. Therefore, a composite system is needed that will improve the properties of the biodegradable food packaging. The aim of this mini-review is to demonstrate recent progress in the synthesis, modification, characterization, and application of bionanocomposites reported by previous researchers. The focus is on the preparation and characterization of CS-based bionanocomposites. The mechanical properties of CS-based food packaging can be improved by adding reinforcement from inorganic materials such as organoclay. Meanwhile, the anti-bacterial properties of CS-based food packaging can be improved by adding nanoparticles such as Ag and ZnO.

The most common type of thermal energy storage material is phase change material (PCM). Because of their low thermal conductivity values and the liquid leaks caused by the transition phase from the solid to the liquid state, these materials have limited applications. To make these materials applicable in a variety of applications, their stabilization within a composite material must be improved. Lauric acid is a saturated fatty acid organic PCM with high latent heat, good chemical and thermal stability, and little supercooling and pollution. To address the leakage issue, expanded organophilic clay treated with cationic surfactant (CTAB) and lauric acid graft-modified cellulose nanofibers were added. In order to increase thermal insulation and lower energy consumption, composite materials based on cement, organophilic clay, and modified cellulose nanofibers were created in this study. These materials are used as shape-stable materials in the building industry. The thermal conductivity of the PCM composite samples increases in direct proportion to the percentages of organophilic clay added, according to research on the thermal behavior of the materials created. The findings indicate that the S5 sample has a thermal conductivity of the order of 0.115 (W m−1 K−1) and that the reduction in thermal conductivity reached 60%. This allows for the best thermal insulation performance due to the prepared material's stability heat, making the material promising for thermal energy storage. The results of the (DSC) thermal properties revealed that the fusion temperature and latent heat of the composite materials were 21.56 °C and 88.5 J g−1, respectively, and supercooling degrees for the nanofiber cellulose–lauric acid composite decreased to 13.99 °C compared to 20.28 °C for pure lauric acid. The FTIR and XRD techniques confirmed the production of the organophilic clay. The addition of clay to the nanofiber cellulose–lauric acid composite material solves the leakage impacts with the phase change material. [ABSTRACT FROM AUTHOR]

Nano-black carbon (NC) and partially de-aluminated kaolinitic clay (PDK) composite blend was investigated as an additive to mortar fabrication for improving of the compressive strength. PDK was obtained from aluminum sulphate of Egypt (ASCE). PDK was grounded with nanocarbon. PDK achieved a good pozzolanic activity, it reached 120 %. The experimental protocol included chemical and physical properties of the PDK/Nano-carbon (NCPDK) and the produced mortars. The effect of five weight ratios of NCPDK (0, 5, 10, 15 and 20 %) on the properties of the formed OPC mortars was investigated. Each ratio was tested with three contents of Nanocarbon (1, 2 and 3 %) by weight. The accelerating effect of NCPDK was clear on the initial setting time whereas it reduced by about 31 % and the final setting time reduced by 23 % at 10 % NCPDK. The reduction in the initial flowability of OPC mortar reached 2.7 and 6 % for 10 and 20 % replacement respectively of the OPC by NCPDK and After 60 minutes from mixing, the relative flowability loss was 68 % at 10 % NCPDK and 88 % at 0 % replacement. The compressive strength values of the produced mortars ranged between 46.2 and 50.7 MPa (EN 196-1), with a maximum improvement equal to 14.4 % using 10 % NCPDK. There was no significant change in the pH values of the mortar mixtures. According to the obtained results the composite NCPDK can be used as an additive material in mortar fabrication. The structure of the hardened mortar modified with 10% NCPDK was investigated by XRD, FTIR and TGA that assured formation of more CSH. Incorporation of Nano-carbon enhanced the compressive strength. [ABSTRACT FROM AUTHOR]

This work aimed to compare the coating protection efficiency of C-steel using two kinds of clay: a local Khulays clay (RCKh) from Saudi Arabia and a commercial clay (CCIn) from India. Clay-based polymer nanocomposites have a unique layered structure, rich intercalation chemistry, and availability at low cost. They are promising reinforcements for polymers. The raw clay for both clay types was washed before being treated with NaCl to produce sodium clay (NaC). The cationic surfactant cetylpyridinium chloride (CPC) was then used to convert the NaC into the organoclay (OC) form. Polystyrene/organoclay nanocomposites (PCNs) were prepared by combining different concentrations of organoclay (1%, 3%, and 5% OC) in toluene solvent and polystyrene (PS) as the matrix. To ensure the success of the PCN modification process, the organoclay and PCN films were characterized using a variety of techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The shifts in the FT-IR spectra after the CPC treatment of NaC confirmed the presence of CPC in the organoclay samples and the presence of OC in the PCNs. The exfoliated structure was obtained from the XRD spectrum for low clay loading (1–3% PCN), while the intercalated structure was the dominant form for the 5% PCN. The XRD results were confirmed by TEM images. To calculate the coating efficiency of the PCNs, various electrochemical methods were used. The electrochemical measurements included electrochemical impedance spectroscopy (EIS), the electrochemical frequency modulation (EFM) method, and Tafel plots. The PCN with a concentration of 1 wt.% OC has a fully exfoliated structure and higher coating efficiency than the PCNs with partially exfoliated structures (3 wt.% and 5 wt.%). It was found from the Tafel plots that commercial Indian clay has better corrosion protection (81.4%) than local Khulays clay (60.2%). A comparison with other studies using current density values shows that our results are superior to those of many studies. [ABSTRACT FROM AUTHOR]

Polyethylene materials are of great interest to be used in many applications due to their many advantageous characteristics. It is light, highly chemical resistant, easy to process, low in cost and has good mechanical properties. Polyethylene is widely used as a cable-insulating material. However, research is still needed to further improve its insulation quality and properties. In this study, an experimental and alternative approach through a dynamic modeling method was conducted. The main objective was to investigate the effect of modified organoclay concentration on the properties of polyethylene/organoclay nanocomposites by observing their characterization and optical and mechanical properties. The thermogram curve reveals that 2 wt% organoclay used has the highest crystallinity (46.7%) while the highest amount of organoclay used produced the lowest crystallinity (31.2%). The presence of cracks was also observed mostly in the nanocomposite with higher content of organoclay, usually where 2.0 wt% and above of organoclay was used. Morphological observation from simulation results supports the experimental work. Only small pores were observed to form in lower concentrations, and as the concentration was increased to 2.0 wt% and above, the pores present became larger in size. Increasing the concentration of organoclay up to 2.0 wt% reduced the interfacial tension while increasing the concentration above 2.0 wt% did not bring any changes to the interfacial tension value. Different formulations produced different behavior of nanocomposite. Hence the control of the formulation was important to control the final result of the products for appropriate application in different sectors of industry. [ABSTRACT FROM AUTHOR]

The present study aims to explore the impact of pristine and surfactant-modified clays (montmorillonite, bentonite and vermiculite) on the thermomechanical properties of a poly (vinyl chloride) (PVC) polymer film. Initially, clay was modified by employing the ion exchange method. The modification of clay minerals was confirmed by the XRD pattern and thermogravimetric analysis. Pristine PVC polymer film and clay (montmorillonite, bentonite and vermiculite)-based PVC polymer composite films were fabricated using solution casting. The ideal dispersion of surfactant-modified organo-clays was observed in the PVC polymer matrix due to the hydrophobic nature of modified clays. The resultant pure polymer film and clay polymer composite film were characterized using XRD and TGA, and their mechanical properties were determined using a tensile strength tester and Durometer. From the XRD pattern, the intercalation of the PVC polymer film was found in the interlayer of organo-clay while exfoliation or partial intercalation and exfoliation were observed for pristine clay mineral-based PVC polymer composite films. Thermal analysis indicated a lowering of the decomposition temperature of the composite film as clay promotes the thermal degradation temperature of PVC. Improvement in the tensile strength and hardness was found to be more frequent in the case of organo-clay-based PVC polymer films, which is only due to the hydrophobic nature of organ clays, resulting in greater compatibility with the polymer matrix. [ABSTRACT FROM AUTHOR]

In this study, gasoil-contaminated clayey sand samples improved with clay nanoparticles in two hydrophilic and organophilic states were cured for 7, 14, and 28 days and were subjected to uniaxial compressive strength (UCS) tests. For this purpose, first, clean soil samples were contaminated with various percentages of gas–oil. The results showed that the unconfined compressive strength of the samples decreases with the increase in soil contamination percentage for all three curing periods. According to the results, the highest decrease of UCS is obtained in the soil with 6 and 8% contamination. Then, by adding different percentages of nanoclay and organoclay to soil contaminated with 6 and 8% gas–oil, we tried to improve the lost properties of the soil. According to results of standard compaction tests, combining contaminated with nanoclay and organoclay could decrease maximum dry density while increasing optimum water. But organoclay had a greater effect than nanoclay on the compaction properties of contaminated soil which can be attributed to the organophilic nature of the organoclay. Based on the results, the compressive strength of the treated samples was increased due to curing. Also, the peak strain corresponding to the UCS decreased during the 28-day curing period compared to the samples with a 7-day curing period. Based on the results, 2 and 0.7 weight percent of clayey sand contaminated with 6 and 8% of gas–oil were found as optimum values for nanoclay and organoclay, respectively. These results were investigated and confirmed by scanning electron microscopy imaging. [ABSTRACT FROM AUTHOR]

In this study, the properties and adsorption behaviors of organoclays synthesized with two structurally different surfactants having the same carbon chain length (hexadecyltrimethylammonium bromide (HDTMAB) and benzyldimethylhexadecylammonium chloride (BDHAC)) were evaluated. The structural properties of the synthesized organoclays were examined using Fourier-transform infrared spectroscopy, zeta potential analysis, X-ray diffraction, and N2 adsorption-desorption test. The modified clays with increased surfactant loadings (from 0.5 CEC to 3 CEC) were prepared to find the optimal surfactant loading. As a result, 1.5 cation exchange capacity (CEC) was found to be the optimal surfactant loading. The organoclay prepared using HDTMAB (H-Bt) exhibited the maximum adsorption capacity of 114.3 mg/g for anionic Orange G dye, which was 1.74 times higher than that of the organoclay prepared using BDHAC (B-Bt). Furthermore, in the presence of a mixture of cationic and anionic dye molecules in water, H-Bt tended to remove more of the cationic target compound than B-Bt (i.e., methylene blue (MB)), suggesting that H-Bt can serve as a more efficient adsorbent for the uptake of environmental contaminants in practical scenarios. Moreover, this study examined the effects of surfactant molecules on the structural properties of organoclays and their adsorption behaviors in the uptake of dye molecules. [ABSTRACT FROM AUTHOR]

Herein, a highly porous bimetal–organic framework (bi-MOF) based on cobalt and nickel was successfully in situ grown on organoclay (OC) clusters by solvothermal method. Accordingly, the hierarchical porous CoNi-MOF/OC composite with a superior specific surface area of 2046 m2/g and a large pore volume of 0.763 cm3/g was obtained, which facilitated the adsorption of organic dyes. A morphological study using scanning electron microscopy indicated the formation of uniform bi-MOF crystals on the OC plates. Furthermore, the single- and multi-dye adsorption assays were implemented to precisely evaluate the adsorption capacity and selectivity of CoNi-MOF/OC composite to anionic and cationic dyes. The results revealed a high adsorption capacity of 58.61 mg/g at an adsorbent content of 15 mg, initial dye concentration of 20 ppm, and contact time of 25 min for MB, which is superior to several existing clay-based adsorbents. The adsorption kinetics study showed that the adsorption of cationic and anionic dyes onto the CoNi-MOF/OC composite followed the pseudo-second-order kinetic model. Interestingly, the regeneration study showed appropriate reusability and stability of the CoNi-MOF/OC composite for the removal of organic dyes with an almost unchanged structure after four regeneration cycles. The results of this study provide new insights for the rational design and fabrication of next-generation clay-based adsorbent by combining the synergistic advantages of bi-MOF with superior specific surface area and pore volume with organoclay composition and structure. [ABSTRACT FROM AUTHOR]

Epoxy nanocomposites are promising for adhesive applications due to their high performance. In this work, an organoclay (PO), prepared by cationic exchanging using a quaternary phosphonium salt or a silylated PO (SPO) was added to an epoxy‐amine resin‐based adhesive to reduce its dripping. PO and SPO were dispersed in the epoxy network on a nanometric scale, mainly in an intercalated structure. A liquid‐to‐gel transition occurs at 4–6 wt% PO due to forming a continuous organoclay network throughout the epoxy volume, eliminating its dripping. The PO addition accelerates the curing reaction initially, and cured nanocomposites with over 3 wt% PO show a drastic reduction in the glass transition temperature (Tg). Moreover, a broadening of the secondary relaxation observed by DMA indicates an interaction between the epoxide‐amine oligomers with the silicate surface. This interaction, associated with forming a continuous organoclay network at 4–6 wt% PO, reduces the epoxy‐amine oligomers diffusion, resulting in their partial curing and consequent Tg decreasing. EPOXY_SPO nanocomposites show Tg values similar to or higher than that observed for the epoxy‐amine network attributed to the forming of covalent bonds between the glycidyloxypropyl end groups in the SPO surface and the hardener amine. [ABSTRACT FROM AUTHOR]

Attapulgite (ATT) is a multi-purpose nanomaterial, which can be used as a reinforcing filler for polylactic acid (PLA) and improve its barrier performance. However, due to the high content of ATT, it is easy to cause agglomeration. In this study, acetyl tributyl citrate (ATBC) was used to improve the toughness of PLA, and the plasticizer could reduce the polymer viscosity and improve the processability, which may contribute to the dispersion of ATT in PLA. The results show that a small amount of ATBC can improve the fracture elongation, crystallinity, water absorption, hydrolysis, and biodegradability of PLA. On the other hand, when ATT is added to PLA/ATBC sample by 10%, the tensile strength, and thermal degradation temperature can be greatly improved and reach the maximum value. Compared with pure PLA, the tensile strength is significantly increased by 33.4% (60.3 MPa), the elongation at break increased by 177.56%, and the thermal degradation temperature increased significantly by about 20.1 ℃. According to the scanning electron microscope and energy dispersive spectrometer, when ATT ≤ 10%, the nanofiller has excellent dispersion in the matrix, but when ATT > 10%, the nanofiller appears serious agglomeration and interfacial phase separation, which is caused by the incompatibility between PLA and ATT, so the performance of the nano composite is greatly reduced. From the results of soil burial and hydrolysis tests, the weight loss rate of PLA/ATBC samples increased with the increase of ATT nanofiller content. The influence of the internal and external tightness of the sample structure on the biodegradability was explained from the analysis results of water absorption and contact angle. The synergy of ATT and ATBC improves the comprehensive performance of PLA and increases its feasibility as a packaging material. [ABSTRACT FROM AUTHOR]

Polymer clay nanocomposites, which can exhibit many superior properties compared to virgin polymers, have gained increasing interest and importance in recent years. This study aimed to prepare composites of two organoclays with unusual ratios and different degrees of lyophilicity with low-density polyethylene and compare their textural structures and thermal and mechanical properties with those of virgin polymer. For this purpose, firstly, organoclays, hydrophobic and superhydrophobic organoclays (OC and SOC), were prepared by solution intercalation method using cetyltrimethylammonium bromide with and without addition of a hydrocarbon substance. Then, using both organoclays, polyethylene organoclay composites were prepared and characterized using X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Additionally, tensile and hardness tests were performed to determine the mechanical properties of the composites, and differential scanning calorimetry (DSC) thermograms were taken to examine their thermal behavior. XRD patterns and HRTEM images of hydrophobic and superhydrophobic organoclays and the composites show that the characteristic smectite peak of the clay shifts to the left and expands, that is, the interlayer space widens and, in the composites, it deforms immediately at low clay ratios. HRTEM images of the composites prepared especially with low clay ratios indicate that a heterogeneous dispersion of clay platelets occurs, indicating that nanocomposite formation has been achieved. On the contrary, in the composites prepared with high clay ratios, this dispersion behavior partially turns into aggregation. In the composites prepared using up to 20% by weight of superhydrophobic organoclay, extremely stable and continuous improvements in all mechanical properties were observed compared to those of the composites prepared using hydrophobic organoclay. This indicates that by using superhydrophobic organoclay, a ductile nanocomposite of polyethylene containing inorganic components in much higher than usual proportions can be prepared.

Resistive switching properties of layered graphene oxides (GOs) filled polymer nanocomposites (PNCs) have received tremendous attention in the field of memory devices. Herein, we report highly stable write-once-read-many-times (WORM) resistive switching properties of exfoliated GOs embedded poly(methyl methacrylate) (PMMA) thin films. The WORM characteristics of the PNC devices have been studied by varying the active layer thickness and the content of GO nanofillers. A disrupted carbon network of GOs enables defect states that act as an energy barrier for carriers and the charge transport through the PNC devices is blocked at a lower electric field. At an elevated electric field, GO sheets embedded PMMA offers percolation pathways for electron transfer, thereby making the composites electrically more conductive. The set voltage (VSET) decreases with a decrease in the active layer thickness, whereas VSET increases with a decrease in the GOs content within PNC devices. For a fixed compliance current (∼1 μA), highest ION/IOFF ratio ∼104 at 1.87 V has been achieved for the PNCs device spin-coated at 9000 rpm with 0.1 wt. % GOs content. The stability of the devices has been confirmed through retention test up to 104 s. In addition, the J-V curves are fitted and an appropriate conduction mechanism is proposed. [ABSTRACT FROM AUTHOR]

The paper provides an overview of biocosmetics, which has tremendous potential for growth and is attracting huge business opportunities. It emphasizes the immediate need to replace conventional fossil-based ingredients in cosmetics with natural, safe, and effective ingredients. It assembles recent technologies viable in the production/extraction of the bioactive ingredient, product development, and formulation processes, its rapid and smooth delivery to the target site, and fosters bio-based cosmetic packaging. It further explores industries that can be a trailblazer in supplying raw material for extraction of bio-based ingredients for cosmetics, creating biodegradable packaging, or weaving innovation in fashion clothing. Lastly, the paper discusses what it takes to become the first generation of a circular economy and supports the implementation of strict regulatory guidelines for any cosmetic sold globally. [ABSTRACT FROM AUTHOR]

TiO2/montmorillonite composites were synthesized using inverse micellar route for the preparation of titania nanoparticles (4–6 nm diameter) in 1-hexanol and for the dispersion of one of the clay components. Two series of composites were obtained: one derived from cetyltrimethylammonium organomontmorillonite (CTA-Mt), exfoliated in 1-hexanol, and the other from sodium form of montmorillonite (Na-Mt) dispersed by formation of an inverse microemulsion in 1-hexanol. The TiO2 content ranged from 16 to 64 wt.%. The composites were characterized with X-ray diffraction, scanning/transmission electron microscopy/energy dispersive X-ray spectroscopy, thermal analysis, and N2 adsorption-desorption isotherms. The Na-Mt-derived component was shown to undergo transformation to CTA-Mt, as indicated by basal spacing of 17.5 nm, due to the interaction with the CTABr surfactant in inverse microemulsion. It was also better dispersed and intermixed with TiO2 nanoparticles. As a result, the TiO2/Na-Mt series displayed superior textural properties, with specific surface area up to 256 m2g−1 and pore volume up to 0.247 cm3g−1 compared with 208 m2g−1 and 0.231 cm3g−1, respectively, for the TiO2/CTA-Mt counterpart. Members of both series were uniformly mesoporous, with the dominant pore size around 5 nm, i.e., comparable with the dimensions of titania nanoparticles. The advantage of the adopted synthesis method is discussed in the context of other preparative procedures used for manufacturing of titania-clay composites. [ABSTRACT FROM AUTHOR]

Ethylene‐vinyl acetate (EVA) copolymer was melt‐blended with different inorganic particles, such as alumina trihydrate (ATH), montmorillonite‐based organoclay (CLO15A) and organophilic silica (R202) to produce (nano)composites with outstanding electrical breakdown strength. The composites loaded with different amount of particles were characterized by dielectric, rheological, morphological and mechanical properties. The addition of the particles resulted in an increase of electrical breakdown strength, whose results depend on the nature and amount of filler. The addition of 1%–5% of ATH resulted in an increase of 50% of this property. Similar results were observed for the composites loaded with 7% of CLO15A and R202. All composites displayed low values of dielectric constant and dielectric loss, which is interesting for insulator applications. The presence of the filler did not exert great influence on the rheological properties of the composites, thus keeping the good processability of EVA matrix. Finally, the composites containing the organoclay presented the best mechanical response. [ABSTRACT FROM AUTHOR]

This study was conducted to ascertain the effect of heavy metals on the general quality of borewell water in a municipality near Kollam District, Kerala state, India. Red-water iron contamination in borewell water has been a major concern for many years that has not been fully resolved. This research introduces an innovative, reliable, and efficient organoclay scavenger for the adsorptive removal of Fe(III) ions from watersheds, by grafting MBO onto Na-MMT clay (MBO/Na-MMT), which was produced via one-pot oxidation reaction using H 2 O 2 to introduce the active functional groups, like the -SOH group, onto the montmorillonite clay. This special alteration of this material improved Na-MMT's capacity to adsorb ferric ions. To evaluate the material's characteristics, X-ray diffraction, SEM-EDS, FTIR, CHNS, TG, and Zeta potential were used. Batch adsorption tests with different solution pH, Fe(III) ion concentrations, agitation periods, adsorbent dose and temperatures were conducted in order to optimise the adsorption procedure. The MBO/Na-MMT exceeded several of the reported adsorbent materials in the literature with an impressive adsorption capacity of 83.33 mg/g and efficiency (97.9%), which was accomplished by spontaneous complexation reaction. Fe(III) spontaneously attached to MBO/Na-MMT by a complex formation reaction mechanism with PSO kinetics and the variability of the adsorption process was highlighted by Elovich kinetic model because of heterogeneity of the surface. The adsorbent material demonstrated a remarkable capability for regeneration, ensuring the material's stability and reusability. [Display omitted] • The adsorption capacity of MBO/Na-MMT for Fe(III) ions was examined. • Fe(III) ion enhanced adsorption capacity of 83.33 mg/g was attained. • A SN2 Mechanism is used in one-pot oxidation to activate chemicals. • FTIR, XRD, SEM, and pH experiments were used to suggest the mechanism of Fe(III) ion binding. • Excellent material reusability for adsorption. [ABSTRACT FROM AUTHOR]

The research of organoclays has been occurring for many years to develop and add value to these inorganic materials for several industrial applications, such as pollutant absorbers or impermeable plastics. The organoclay applications are intrinsically related to organo-modification and the structure of clays. This study shows the preparation and characterization of organoclays produced by a nontronite type clay (calcic bentonite) from the Tosagua Formation in the peninsula of Santa Elena in Ecuador. These clays were purified and centrifuged before organo-treatment. The purification and separation processes were used to remove organic matter and carbonates, and a cationic interchange from calcic to sodic (Ca2+ to Na+) was carried out. Organo-modification was performed using two types of cationic compounds, i.e., Oleylmethylbis (2-hydroxyethyl) ammonium chloride and Di (hydrogenated tallow alkyl) quaternary amine to organoclay with different surface hydrophobicity. The samples were characterized by X-ray diffractometry (XRD), infrared spectrometry (FT-IR), thermo-gravimetry (TGA), and scanning electron microscopy (SEM) to analyze the effect after the mentioned treatment and the resulting organoclays by the addition of these surfactants. The results confirm the significant intercalation of the organic treatment suitable for environmental remediation, compatibilizing recycled plastics, or improving performance in different hydrophobicity systems for industrial applications. [ABSTRACT FROM AUTHOR]

In this original research, biodegradable corn starch (CS) and wheat gluten (wg)-based silver nanofilms were synthesized and analyzed by using goji berry extract taurine (ta), garlic extract (GC), whey powder (wh), and montmorillonite clay nanoparticles. Antibacterial-corn-starch-based nano films were analyzed by using the methods of high-performance liquid chromatography (HPLC), Fourier Transform infrared spectroscopy (FTIR-ATR), X-ray diffraction (XRD), dynamic and mechanical (DMA) analysis, and scanning electron microscopy (SEM). In addition, the antibacterial resistances of the corn starch nano films against the bacteria Salmonella and Staphylococcus aureus (S. aureus) and Listeria monocytogenes were examined and the migration assays were carried out. The migration analysis results of CS1, CS2, and CS3 nanocomposite films were found as 0.305, 0.297, and 0.297 mg/dm2, respectively. The inhibition zone of CS1, CS2, and CS3 nanocomposite films were found as 1547, 386, and 1884 mm2 against Salmonella bacteria. The results show that silver nanofilms are suitable as packaging films for the production of packaging in milk and dairy products, liquid foods, and acidic foods. [ABSTRACT FROM AUTHOR]

In this work, a series of Ni/Organoclay catalysts with different Nickel loadings were prepared by the wet-impregnation method for the catalytic hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL). Reaction parameters such as reaction temperature, pressure, solvent effect, and wt% of catalyst were optimized to get excellent conversion of levulinic acid selectively to γ-valerolactone. Ni/Organoclay with 30% Nickel loading exhibited 100% conversion of LA with 100% selectivity towards GVL at 140 °C and 3.0 MPa H 2 pressure using 1,4-dioxane as a solvent in 5 h. Different bulk and surface characterization techniques such as XRD, BET, FE-SEM, HR-TEM, XPS, XRF, NH 3 -TPD, and H 2 -Chemisorption were used to characterize the Ni/Organoclay catalyst. BET and NH 3 -TPD analysis showed that the pre-treatment of bentonite with surfactant (CTAB) improved the pore volume, surface area, and acidity of Organoclay which assisted in improving the conversion and selectivity of LA and GVL respectively. [Display omitted] • The calcination of catalyst in N 2 resulted in highly dispersed nickel particles. • Ni/Organoclay exhibits 100% LA conversion and 100% GVL selectivity. • 100% selectivity towards GVL was achieved in 1,4-dioxane. • Catalyst showed excellent hydrogenation activity even at 1.0 MPa H 2 pressure. [ABSTRACT FROM AUTHOR]

Both biodegradable UV-blocking and antimicrobial films are extremely demanded, especially for food packaging to meet the increasing sustainable requirement for the human health and the environment. Thus, the objective of this research was to fabricate antibiofilms based biodegradable Poly(butylene adipate-co-terephthalate) / organoclay (PBAT/OC) bionanocomposites incorporating with different proportions of cumin essential oil (CEO) as a toxicity-free product without requiring ZnO, TiO2, Ag-NPs or other nanoparticles. The composition of CEO was characterized by GC-MS. PBAT/OC bionanocomposites with variable proportions of CEO were prepared by solvent casting approach. The synergistic effect of CEO on the morphology, UV-shielding, and antibacterial/antioxidant activities was studied. The results revealed that the dispersion of clay layers in the matrix was affected when the CEO content was increased. The incorporated natural CEO into PBAT/OC nanocomposite was enhanced the UV-shielding properties (i.e. 100% blocking for UV-B and nearly up 95% for UV-A), and antimicrobial/antioxidant activities, especially at high oil concentration. Whereas for mechanical properties, the findings showed inferior tensile and modulus values, because of plasticizing CEO effect. The data in this research provide very promising formulations for fabricating sustainable PBAT-based antimicrobial and UV-protecting films for perspective applications in light-sensitive packaging such as drugs, food products or in agriculture mulch films. [ABSTRACT FROM AUTHOR]

This paper presents the influence of the presence of a modified organoclay, Cloisite® 20A (MMTA) on the structural and drug release properties of ureasil organic–inorganic hybrid. Sol–gel process was used to prepare the hybrid nanocomposites containing sodium diclofenac (DCF) at 5% wt. The effect of the amount of MMTA incorporated into the ureasil hybrid matrix was evaluated and characterized in depth by different techniques such as X-ray diffraction (XRD), small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and swelling properties. The influence of MMTA on ureasil nanocomposites release profile was evaluated by in situ UV–vis. The diffraction patterns of the UPEO–MMTA nanocomposites showed a synergistic contribution effect that led to an intensity increase and narrowed the diffraction peaks, evidencing a crystallite PEO growth as a function of the modified nanoclay content. The interactions between polyether chains and the hydrogenated tallow of MMTA led to an easy intercalation process, as observed in UPEO–MMTA nanocomposites containing low (1% wt) or high (20% wt) nanoclay content. The waterway (channels) created in UPEO–MMTA nanocomposites contributed to a free volume increase in the swollen network compared to UPEO without MMTA. The hypothesis of the channels created after intercalation of the PEO phase in the interlayer of MMTA containing organoammonium ions corroborates with the XRD results, swelling studies by SAXS, and release assays. Furthermore, when these clay particles were dispersed in the polymeric matrix by an intercalation process, water uptake improvement was observed, with an increased amount of DCF release. The design of ureasil-MMTA nanocomposites containing modified nanoclay endows them with tunable properties; for example, swelling degree followed by amount of controlled drug release, opening the way for more versatile biomedical applications. [ABSTRACT FROM AUTHOR]

The objective of this study was to obtain insight into the synthesis and structural changes of organo-montmorillonite (OMT) by tailoring montmorillonite (MMT) with the help of a quaternary ammonium salt. The OMT was prepared as a precursor to the development of enhanced asphalt rubber (AR) product. The dimethyldioctadecylammonium chloride (DDAC) provided the required thermodynamic driving force for changing the polarity of hydrophilic MMT to organophilic when both materials were mixed at 80°C under constant stirring for about 12 h. The newly synthesized OMT and base MMT were thoroughly characterized by using particle size analyzer, zeta potential, infrared (IR) spectroscopy, powder X-ray diffraction, and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) measurements encompassing 20,936 data points. The SEM images of OMT depicted the grafted fibrils of long-chain aliphatic hydrocarbons. At the same time, EDX indicated the exchange of sodium and magnesium cations with carbon and nitrogen of the DDAC. Comparison of the IR spectra for reactants and OMT powders concluded that water molecules were removed and methyl/methylene functional groups were inserted in the OMT. The 100 basal reflections of OMT were 1.894 nm, while that of untreated MMT was 1.522 nm, which corroborated the intercalation of the long alkyl chains of the DDAC, a cationic surfactant in the OMT. The study established a simple method for the preparation of OMT to be used as an AR modifier for roadway applications supporting the utilization of nanoclay material in resolving storage stability issues and enhancing properties of recycled rubber–based asphalt products. [ABSTRACT FROM AUTHOR]

A simple method for organically modifying a natural acid clay (Japanese acid clay) rapidly with alkylamine has been developed. Japanese acid clay mainly consists of acidic montmorillonite and was successfully modified with decylamine in water at room temperature for a short time period (10 min) using an ultrasonic bath without any pretreatments. The structure of the modified clay changed from exterior surface modification to intercalation with an increase in the decylamine content. The equilibrium adsorption capacity for the anionic dye methyl orange (MO) increased with increasing decylamine content. The adsorption kinetics and isotherm were well described by the pseudo-second-order and Langmuir models, respectively. Better MO adsorption was obtained under the conditions of high dosage, low pH value, and low temperature. The adsorbent was also found to have good adsorption for not only MO but also other anionic dyes (Congo red and eosin Y) and cationic dyes (methylene blue, crystal violet, and rhodamine B). In particular, the decylamine-intercalated clay adsorbent exhibited a high level of adsorption capacity for Congo red and crystal violet. The results demonstrate that the synthesis process can provide a simple and cost-effective organoclay as an adsorbent with high performance for the removal of anionic and cationic dyes. [ABSTRACT FROM AUTHOR]

The processing parameters to disperse active filler within a polymer matrix to enhance the polymers' properties should be selected carefully to achieve the best dispersion. In this research, Box-Behnken Design (BBD), an experimental design for response surface methodology (RSM), with three levels was used as a design of experiment (DOE) to analyze the effect of processing parameters on the thermal and rheological properties of high-density polyethylene-organoclay (HDPE-OC) composites prepared by adding organoclay (OC) to high density polyethylene (HDPE) using melt blending method. HDPE-OC composites were characterized morphologically by SEM and XRD, and thermally by DSC and TGA, and tested rheologically. Investigated factors were filler amount, mixing temperature and screw speed. The evaluated responses were melting temperature, degradation temperature, storage modulus, and complex viscosity of HDPE-OC composites. The effect of each factor on the responses was determined through an analysis of variance (ANOVA). The obtained data was used to predict the responses by fitting into a second order equation with MINITAB software. Constructed models were verified using validation experiments therefore optimum melt blending processing parameters obtained as 1.5 wt.% of OC, mixing temperature of 183 °C, and screw speed of 77 rpm for HDPE-OC composites. [ABSTRACT FROM AUTHOR]

The blending of polymers leads to materials with the desired combined properties. These properties can further be improved by the incorporation of compatibilizer, organoclay, or both. In the present manuscript, the effects of compatibilizer and organoclay, as well as their combined use on the rheological, thermal, and mechanical properties of styrene copolymer blends, is examined. Styrene-containing copolymers blends were prepared by melt-mixing in a twin screw extruder. The addition of SAN into ABS decreases its thermal stability, whereas it increases its tensile strength and modulus. The incorporation of organoclay in ABS/SAN blends increases their viscosity and slightly improves their thermal stability and significantly improves the tensile and storage moduli. In PC/SAN blends, the SAN copolymer increases the flow rate, as well as the tensile strength and modulus of PC, whereas it decreases the thermal stability. The addition of ABS-g-MAH compatibilizer in PC/SAN blends increases the melt viscosity and maximum decomposition rate temperature of SAN phase, while it leads to the earlier decomposition of the PC phase. The incorporation of organoclay reinforcement enhances the thermal decomposition resistance of thes SAN phase. The opposite effect was recorded for the PC phase. The addition of organoclay enhances the elastic modulus of PC/SAN hybrids. [ABSTRACT FROM AUTHOR]

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This research aims to enhance the mechanical characteristics of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by using epoxidized natural rubber (ENR-25 and ENR-50) as a toughening agent and polybutadiene (PB) grafted with maleic anhydride (MA) (3 MA groups/chain) as a compatibilizer. The PHBV/ENR blends were mixed in 100/0, 90/10, 80/20, and 70/30 with PB-g-MA at 0, 5, and 10% (wt./wt.), using an internal mixer set to 175 °C with a rotor speed of 50 rpm. The findings indicated that at 70/30 PHBV/ENR composition, the impact strength of the blends with 25 and 50 epoxide contents were the greatest at 6.92 ± 0.35 J m−1 and 7.33 ± 1.19 J m−1, respectively, which are about two times greater than that of neat PHBV. Furthermore, the biodegradability of the PHBV/ENR blends was more substantial than that of neat PHBV, showing a mass reduction of approximately 40% and 45% for PHBV/ENR-25 and PHBV/ENR-50, respectively. In comparison, while the mass loss of PHBV was approximately 37% after three months of soil burial. The results indicate that ENR improves the toughness of the blends while simultaneously increasing PHBV degradation, which could pave the way for broadening PHBV for sustainability purposes. [ABSTRACT FROM AUTHOR]

Poly(amic acid) (PAA) is prepared by the reaction of dianhydride 4,4′-biphthalic anhydride and diamine bis[4-(3-aminophenoxy)phenyl]sulfone in N,N'-dimethylacetamide. Two types of fillers were dispersed in the as-synthesized PAA via a solution intercalation method; polyimide (PI) hybrid films were synthesized under various heat treatment conditions. Octylamine (C8) was introduced into graphene sheets (C8-GS) and bentonite (C8-BTN), which were then used as nanofillers in the PI hybrid films. The synthesized nanofillers were used in varying amounts of 0.25–1.00 wt% with respect to the matrix PI. The thermal and morphological properties and optical transparency of the hybrid films were investigated and compared for both C8-GS and C8-BTN at varying nanofiller content. The C8-BTN nanocomposite showed superior thermal properties, and optical transparency, and the filler was well dispersed in the PI matrix compared to the C8-GS nanocomposite. The thermal stability of the hybrid films improved upon the addition of small amounts of the nanofiller. However, beyond a certain critical filler concentration, the thermal stability declined. These results were verified through the dispersion of fillers via transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Cross-linked polyvinyl chloride (C-PVC) foams and their nanocomposite foams, containing Cloisite 30B nanoclays were prepared. The effects of compression molding pressure and time on the morphology and mechanical properties of different foams were studied. Increment of molding pressure led to higher apparent density, gel content, cell density, and expansion ratio, and wider cell size distribution, which improved the mechanical properties of the foams. Additionally, with the increasing of molding time, lower cell density and final expansion ratio, narrower cell size distribution, and higher gel content and mechanical properties could be obtained. Moreover, incorporation of Cloisite 30B nanoclay in a PVC matrix not only improved cellular microstructure and mechanical properties but also reduced water uptake ratios of nanocomposite foams. [ABSTRACT FROM AUTHOR]

In this work, we report a new facile method for the preparation of myrcene-limonene copolymers and nanocomposites using a Lewis acid as a catalyst (AlCl3) and organo-modified clay as a nano-reinforcing filler. The copolymer (myr-co-lim) was prepared by cationic copolymerization using AlCl3 as a catalyst. The structure of the obtained copolymer is studied and confirmed by Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance spectroscopy, and Differential Scanning Calorimetry. By improving the dispersion of the matrix polymer in sheets of the organoclay, Maghnite-CTA+ (Mag-CTA+), an Algerian natural organophilic clay, was used to preparenanocomposites of linear copolymer (myr-co-lim). In order to identify and assess their structural, morphological, and thermal properties, the effect of the organoclay, used in varyingamounts (1, 4, 7, and 10% by weight), and the preparation process were investigated. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process in which they were used as green nano-reinforcing filler. The X-ray diffraction of the resulting nanocomposites revealed a considerable alteration in the interlayer spacing of Mag-CTA+. As a result, interlayer expansion and myr-co-lim exfoliation between layers of Mag-CTA+ were observed. Thermogravimetric analysis provided information on the synthesized nanocomposites' thermal properties. Fourier transform infrared spectroscopy and scanning electronic microscopy, respectively, were used to determine the structure and morphology of the produced nanocomposites (myr-co-lim/Mag). The intercalation of myr-co-lim in the Mag-CTA+ sheets has been supported by the results, and the optimum amount of organoclay needed to create a nanocomposite with high thermal stability is 10% by weight. Finally, a new method for the preparation of copolymer and nanocomposites from myrcene and limonene in a short reaction time was developed. [ABSTRACT FROM AUTHOR]

The present study comprises the surfactant-based modified adsorbents as inorgano–organo composites for the removal of dyes. It was depicted that 0.05 g of modified clay could be efficiently used to adsorb >90% of dye (100 mg/L). The kinetic models (pseudo-first order, pseudo-second order, intraparticle diffusion model) and isothermal models (Langmuir, Freundlich, Temkin) were also studied to examine the adsorption mechanism. Pseudo second-order kinetic model and Langmuir isothermal model fitted well with adsorption of dyes. The thermodynamic ( Δ G ° , Δ H ° and Δ S °) parameters were also studied and negative value of ( Δ G °) and positive value of ( Δ S °) indicates the spontaneity of adsorption. [ABSTRACT FROM AUTHOR]

An efficient and environmentally friendly strategy is demonstrated for improving the clay dispersion in non-polar rubbers and enhancing their interaction at the interface. In this work, we introduced butadiene-styrene-vinyl pyridine rubber (VPR) latex into clay gel to prepare VPR/clay gel, which was then incorporated into the styrene-butadiene rubber (SBR) to prepare SBR/VPR/clay nanocomposites (NCs), by gel compounding method. The results showed that the dispersion of the clay layer improved by the incorporation of VPR, and the interfacial strength between clay and rubber increased. As a result, the mechanical properties of SBR/VPR/clay NC significantly improved. The tensile strength of SBR/VPR/clay NC was up to 16.3 MPa, which was 930 % higher than that of the pure SBR and nearly 30 % higher than that of the SBR/organoclay nanocomposite (SBR/oclay NC) with the same filler loading. [Display omitted] • Environmentally friendly clay minerals recognized as potential rubber reinforcement fillers. • Gel compounding method is environmentally friendly and easy to operate compared to conventional methods of preparing clay/rubber nanocomposites. • Gel compounding method has been poorly used in non-polar rubbers and therefore needs to be improved. • Interfacial strength of SBR (a non-polar rubber)/clay nanocomposites was successfully improved by introducing VPR modified clay gels. [ABSTRACT FROM AUTHOR]

• Biobased fertilizers offer 120-day nitrogen release at a 4 wt% coating ratio. • Biowaste-derived bionanocomposite can coat urea for well-tunable nitrogen release. • A mathematic model is built to design tailored slow-release porous materials. • This BCRF offers extended N-release, cost-efficiency, and tunability. Controlled-release fertilizers (CRFs) present a promising solution for alleviating food and nutrient scarcity. However, their development has been mainly hindered by both rapid and unsynchronized nutrient release and unsustainable coating materials. In this study, we address this issue by developing a new coating layer for CRFs using a programmable biopolyurethane nanocomposite. This nanocomposite is prepared from diphenylmethane diisocyanate (MDI)-functionalized bentonite nanoclay (BNT-MDI) and a biopolyol from biomass waste. The results show that the BNT-MDI-doped CRFs (BCRFs) exhibit an impressive nitrogen (N)-release longevity of approximately 120 days at a 4 wt% coating ratio, surpassing previous CRF formulations. In a 30-day snap bean cultivation study, BCRF significantly improved root length (1000 %), leaf length (257 %), leaf width (400 %), and plant height (1400 %) compared to the control. The superior performance of BCRF is attributed to the PU-nanoclay biocomposite film, with full nano-exfoliation, controllable porosity, and high crosslinking density. Furthermore, we introduce a new dynamic release mechanism and establish a quantitative relationship between the nanostructure, property, and release performance of BCRF by combining the multiplicative and diffusion models for porous materials. This study provides a theoretical framework and a straightforward methodology for designing programmable nanocomposite structures for future biobased CRFs. [ABSTRACT FROM AUTHOR]

In-situ remediation of mercury at numerous contaminated sites worldwide is a challenging and costly endeavor due to the persistency of this contaminant. In this study, we evaluated eight commercially available sorbent media ranging from carbon-, clays- and silica-based materials (PBC – Biochar, eSorb – Sorbster, nsPAC – Powdered Activated Carbon, fsPAC – Powdered Activated Carbon with Mackinawite, F300 – Filtrasorb 300, Si-SH – Silica Thiol, eBind – RemBind, Q-Clay – Organoclay PM-199), for their effectiveness in sorbing mercury (Hg2+) and mercury complexed with dissolved organic matter (Hg-DOM). Under the chosen experimental conditions of this study, results showed that in the absence of DOM, the kinetic rates of Hg2+ sorption onto the evaluated sorbents were in the order of 0.31 min−1 (Si-SH) to 2.98 min−1 (nsPAC), whereas in the presence of DOM, the rates varied from 0.16 min−1 (F300) to 0.95 min−1 (nsPAC). The measured sorption capacity for Hg2+ in the absence of DOM varied from 3.02 mg/g (Q-Clay) to 35.15 mg/g (Si-SH), whereas in the presence of DOM, calculated partition coefficient (K D) ranged from 69.7 mL/g (Q-Clay) to 41,510 mL/g (Si-SH). Furthermore, kinetic data suggest liquid film diffusion was the rate-limiting steps governing mercury sorption onto the studied media. Overall, the obtained study parameters (kinetics/isotherm) are particularly important in informing robust engineering designs for deployment of the vast majority of evaluated sorbents. Thus, sorbent-based strategies offer viable solutions for cost-effective cleanup of mercury at industrially contaminated sites. [Display omitted] • Enhanced kinetics foster rapid binding of mercury to sorbent media. • Strong binding of mercury to sorbents eliminates the need for spent sorbent disposal in landfills. • Commercial sorbents offer a low-cost strategy for mercury binding, even in environment rich in dissolved organic matter. [ABSTRACT FROM AUTHOR]

Geomimetic materials (GEOMI) are composite materials based on polymer and clays, able to imitate structural and functional properties of soils, including their structure, cationic exchange capability (CEC), water uptake capability (WUC), pH buffering ability, immobilizing of substances, among other. Because they can be used to develop of fertilizer slow-release systems, they have been identified as a novel approach to advance toward a most sustainable agriculture. The aim of this work was to study the effect of GEOMI on the plant growth in degraded soils. For this, GEOMI-1.0 was synthesized using poly(acrylic acid) as model of humic substances and bentonite modified with trichlorovinylsilane as mineral fraction model. Materials were characterized by different techniques. GEOMI-1.0 showed a hybrid, homogeneous, and amorphous structure. In addition, it was thermally stable at below ⁓200 °C with a Tg about 49.3 °C, showed a high WUC (⁓1384 g of water per 100 g of material). Likewise, it was verified that GEOMI-1.0 can decreases the pH values and increases the CEC of degraded soils depending on the added amount of geomaterial; but also, the electric conductivity values showed no dependence on the added amount of GEOMI-1.0. By correlation analysis, an exponential dependence of CEC was observed respect to pH changes, the relative amount added of GEOMI-1.0 and the initial CEC. Finally, using Brachiaria Brizantha cv. Marandú as plant model, the increase in the biomass content of roots and leaves, and the number of germinated seeds, were observed when GEOMI-1.0 was used for restoration of in-lab degraded soils. [Display omitted] • Geomimetic composite materials (GEOMI) can mimic functional properties of soils. • GEOMI was synthesized using PAA as humic substance model and bentonite. • Modified bentonite is obtained by insertion of polymerizable double bonds. • GEOMI can be used to improve the pH and CEC of degraded soils. • Geomimetic materials showed that they can be used for restoration of degraded soils. [ABSTRACT FROM AUTHOR]

As the base oil of the current flat-rheology synthetic drilling fluid is high in cost and not renewable, the biodiesel-based flat-rheology drilling fluid with low-cost, environmental protection and renewable advantage was studied. Based on the optimization of raw materials, a cheap, environment-friendly biodiesel of soybean oil ethyl ester with good fluidity at low temperature was selected as the base oil. By selecting high oil-water ratio and introducing cationic surfactant into the auxiliary emulsifier, the thickening of biodiesel-based emulsion caused by hydrolysis and saponification after high-temperature aging was effectively eliminated. The organoclay prepared with cationic modifier of hexadecyl trimethyl ammonium chloride was used to improve the rheologic properties, stability and fluid loss of the drilling fluid while preventing low-temperature thickening. A flat-rheology modifier was synthesized with dimer fatty acid and cocoanut fatty acid diethanolamide, which could form strong network structure in the biodiesel-based drilling fluid to adjust effectively rheological properties of the drilling fluid. A biodiesel-based flat-rheology drilling fluid system with the density of 1.2 g/cm3 has been formulated which has constant rheology in the temperature range of 2–90 °C, temperature tolerance of 160 °C, seawater salinity tolerance of 5%, shale cuttings tolerance of 10%, and is environmentally friendly.

Linseed oil-based composite films were prepared with cinnamaldehyde (Cin) using a modified clay (organoclay) through in situ polymerization, which is the result of the interaction between Cin and organoclay. The incorporation of organoclay reduces the polymer chain's mobility and, therefore, increases the thermal stability of the composite films. In some experimental conditions, the clay is located both inside and on the surface of the film, thus, affecting the mechanical and thermal properties as well as the surface properties of the composite films. The incorporation of organoclay decreases the water contact angle of the composite film by more than 15%, whatever the amount of cinnamaldehyde. However, the incorporation of cinnamaldehyde has the opposite effect on film surface properties. Indeed, for the water vapor permeability (WVP), the effect of cinnamaldehyde on the film barrier properties is much higher in the presence of organoclay. The incorporation of hydrophobic compounds into the polymer films reduces the water content, which acts as a plasticizer and, therefore, decreases the WVP by more than 17%. Linseed oil has a natural antioxidant activity (~97%) due to the higher content of unsaturated fatty acids, and this activity increased with the amount of organoclay and cinnamaldehyde. [ABSTRACT FROM AUTHOR]

The use of poly (butylene adipate-co-terephthalate) (PBAT) has increased widely but PBAT-degrading bacteria have rarely been studied. During this study, we used farm soil (Shaanxi (yuan Jia cun)) to isolate and identify PBAT-degrading bacteria (Bacillus strains). We then accessed the effect of growth factors on PBAT degradation as well as the lipase activity of PBAT-degrading bacteria. Most active strains (SUST B1, SUST B2, and SUST B3) were selected for degradation study. The lipase activity under different pH, temperature, degradation products, and carbon sources was studied. The degradation mechanism was investigated using attenuated total reflection Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. The results showed that each strain had a significant degrading effect on PBAT. Under certain conditions, the lipase activity of strain SUST B2 was 10.42 U/mL and degraded 10.5% of PBAT films. Results of the study displayed a significant change in PBAT properties throughout the experiment. The pH of the degradation solution also displayed significant reduction throughout the experiment and reached a minimum value at the end of the experiment. The secreted lipase enzyme catalyzed the degradation of ester bonds present in the PBAT structure. Terephthalic acid, 1, 4-butanediol, and adipic acid were the by-products of this reaction. Strains utilize these products as carbon sources hence completely degrading PBAT. The bioremediation of PBAT in the environment can be achieved using these strains. [ABSTRACT FROM AUTHOR]

Novel formulations comprising Arbofill (AR), two flame retardants and clay, were obtained through melt blending. An evaluation of the influence of each filler was performed using thermal analysis, Scanning electron microscopy (SEM), X-ray powder diffraction spectroscopy (XRD), mechanical and fire testing. It was found that the impact strength of the Arbofill matrix increased upon the addition of the filler. SEM micrographs evidenced that composites comprising flame retardants exhibited enhanced interfacial adhesion between the components when the clay was added. The presence of the fillers used led to an increase in thermal stability, as evaluated by the temperature corresponding to 5% mass loss (T5%). The best flame resistance and highest char concentration after thermal degradation were registered for the composite comprising all the fillers. All the developed formulations presented better flame-retardant properties, as compared to the AR matrix. The properties achieved recommend the investigated composites for applications in the electrical and furniture industry. [ABSTRACT FROM AUTHOR]

A composite (Sa‐HTDMA/UiO‐66) consisting of organoclay (Sa‐HTDMA) and a metal‐organic framework (UiO‐66) was prepared using organically modified natural Cameroonian clay and Zr‐MOF. The organoclay was obtained by intercalating in its interlayer hexadecyltrimethyl ammonium cation (HTDMA). The composite was then used to form a film onto a glassy carbon electrode (GCE) by drop coating (Sa‐HTDMA/UiO‐66/GCE). Electrochemical responses recorded at the as‐prepared modified electrodes for ascorbic acid (AA), acetaminophen (AC) and nitrite (NO2−) were investigated using cyclic and linear sweep voltammetry. The results revealed that Sa‐HTDMA/UiO‐66/GCE exhibited a favorable behavior for individual and simultaneous sensing of AA, AC and NO2−. Additionally, compared with UiO‐66 modified GCE, the composite enabled good performance of the electrode. Under the optimum conditions, the linear calibration curves were attained in the following ranges: 1–650 μM for AA, 1–700 μM for AC and 1–600 μM for NO2− with the respective detection limits of 0.01, 0.19 and 0.33 μM. Application of the sensors to determine AA and AC in pharmaceutical preparations, and NO2− in tap water, was successful. [ABSTRACT FROM AUTHOR]

This article proposes a foaming method using supercritical carbon dioxide (scCO2) to obtain compostable bionanocomposite foams based on PLA and organoclay (C30B) where this bionanocomposite was fabricated by a previous hot melt extrusion step. Neat PLA films and PLA/C30B films (1, 2, and 3 wt.%) were obtained by using a melt extrusion process followed by a film forming process obtaining films with thicknesses between 500 and 600 μm. Films were further processed into foams in a high-pressure cell with scCO2 under constant conditions of pressure (25 MPa) and temperature (130 °C) for 30 min. Bionanocomposite PLA foams evidenced a closed cell and uniform cell structure; however, neat PLA presented a poor cell structure and thick cell walls. The thermal stability was significantly enhanced in the bionanocomposite foam samples by the good dispersion of nanoclays due to scCO2, as demonstrated by X-ray diffraction analysis. The bionanocomposite foams showed improved overall mechanical performance due to well-dispersed nanoclays promoting increased interfacial adhesion with the polymeric matrix. The water uptake behavior of bionanocomposite foams showed that they practically did not absorb water during the first week of immersion in water. Finally, PLA foams were disintegrated under standard composting conditions at higher rates than PLA films, showing their sustainable character. Thus, PLA bionanocomposite foams obtained by batch supercritical foaming seem to be a sustainable option to replace non-biodegradable expanded polystyrene, and they represent a promising alternative to be considered in applications such as food packaging and other products. [ABSTRACT FROM AUTHOR]

Well dispersed polyethylene (PE) nanocomposites were developed. Montmorillonite (MMT) as aluminosilicate clay layers was modified using organic silanes of different side chains. The MMT was grafted using 3-(trimethoxysilyl)propylamine, N -[3-(trimethoxysilyl)propyl]ethylenediamine, and trimethoxyvinylsilane. The modification process of MMT using organic different silanes was elucidated using microscopic, thermogravimetric, spectroscopic, and X-ray diffraction tools. Then, the developed organoclays were dispersed uniformly in PE matrix producing well exfoliated and dispersed polymer nanocomposites. The mass loadings of dispersed organoclay were varied and the impact of organic silane structure was studied. Thermal stability and flammability properties of the developed polymer nanocomposites were evaluated. The peak heat release rate and average heat release rate were reduced by 48% and 61%, respectively compared to virgin polymer. Also, the average mass loss rate was significantly reduced by 50%. This is in addition to reduction in emission of carbon monoxide (CO) and carbon dioxide (CO2) by 45% and 56%, respectively. The effect of side chain of organosilane on the performance of modified clay layers was studied. The toxicity of gases evolved during combustion process of PE and their polymer nanocomposites were evaluated using Fourier transform infrared connected to cone calorimeter. Additionally, the influence of organic silane on the pyrolysis and toxic gases emission was further studied. [ABSTRACT FROM AUTHOR]

The aim of this work was to produce filaments of PLA/PBAT and NPK fertilizer adsorbed on organophilized bentonite intended for application in the prototyping of biodegradable agricultural artifacts in 3D printing, using the Fused Deposition Modeling (FDM) technique. This is the first time that we have reported this composite for a 3D printing approach. Systems containing PLA/PBAT, organobentonite and NPK were initially processed in an internal mixer and later extruded as filaments in a single-screw extruder. The prototypes were printed by FDM. Structural, morphological and thermal properties, as well as NPK releasing, were investigated. The results suggest that exfoliated and/or intercalated nanocomposites were obtained by the organoclay addition to the PLA/PBAT blend. The morphological analysis revealed a good surface quality of the impressions. Systems containing organobentonite released approximately 22% less fertilizer in 24 h compared to the systems without organobentonite. This difference is due to the higher concentration of nanoparticles that generate more barriers to the diffusion of NPK. The release data for these systems had a better fit to the kinetic model of Korsmeyer-Peppas. Thus, studied filaments have the potential to retard the release of fertilizer and are suitable for further development of structures for agricultural applications by FDM. [ABSTRACT FROM AUTHOR]

Nanocomposites of hydrophobic organo-clay/polypropylene (organo-clay/PP) were efficiently developed through a solution-blending technique. For this, we utilized various smectite clays as host agents; namely, Na-montmorillonite (Mt, ~1000 nm), Na-fluorine mica (Mica, ~1500 nm), and Na-hectorite (Ht, ~60 nm) with varied sizes, layer charges, and aspect ratios. Such clays were functionalized with cetyltrimethylammonium (CTA) bromide via an intercalation technique to obtain hydrophobic organic clays. The as-made clay particles were further mixed with a PP/xylene solution; the latter was removed to obtain the final product of the CTA-clay/PP nanocomposite. An X-ray diffraction (XRD) analysis confirmed that there were no characteristic (001) diffraction peaks for CTA-Mica in the PP nanocomposites containing CTA-Mica, assuring the fact that the Mica layers could be completely exfoliated and thereby homogenously composited within the PP. On the other hand, the CTA-Mt and CTA-Ht incorporated composites had broader (001) peaks, which might have been due to the partial exfoliation of CTA-Mt and CTA-Ht in the composites. Among the three CTA-clay/PP nanocomposites, the CTA-Mica nanohybrid showed an enhanced thermal stability by ~42 °C compared to the intact host polymer matrix. We also noted that when the CTA-Mica content was ~9 mass % in the nanocomposites, the Young's modulus was drastically maximized to 69%. Our preliminary results therefore validated that out of the three tested clay-PP nanocomposites, the CTA-Mica nanofiller served as the best one to improve both the thermal and mechanical properties of the PP nanocomposites. [ABSTRACT FROM AUTHOR]

In this study, incorporated hexadecyltrimethylammonium (HDTMA) cations to smectite via ion exchange and formed the modified smectite‐HDTMA, a kind of organoclay catalyst. Besides analyzing its physical properties, we also adopted it to conduct adsorption experiments on organic pollutants such as aniline and pentachlorophenol (PCP). In terms of the adsorption of organic pollutants, adsorption reaction reached the saturation point within 2 h and remained unchanged after reaching 8 h when smectite‐HDTMA with a pH value of 7 was used to bind aniline. Moreover, adsorption reaction reached the saturation point within 2 h and remained unchanged after reaching 24 h when smectite‐HDTMA with a pH value of 7 was used to bind PCP. This study also found that high adsorption efficiency of smectite‐HDTMA towards aniline could be achieved; there was a slow but steady increase in the adsorption capacity of smectite‐HDTMA when its equilibrium concentration reached 100 mg/L. Besides, batch adsorption experiments using two solvents showed that smectite‐HDTMA mainly bound aniline and PCP via distribution, meaning that the adsorption capacity of the smectite‐HDTMA remains the same no matter how many kinds of organic compounds are presented and that competitive adsorption does not occur. [ABSTRACT FROM AUTHOR]

Thermoplastic poly(urethane-siloxane)/organoclay nanocomposites (TPU NCs) with different hard segment content (20-55 wt. %) were prepared by in situ polymerization in the presence of organically modified montmorillonite as a nanofiller (Cloisite 30B; 1 wt. %). Hydroxyl-terminated ethoxypropyl- poly(dimethylsiloxane) was used as soft segment, while 4,4'-methylenediphenyl diisocyanate and 1,4-butanediol were the hard segment components. The study of the influence of the hard segment content on the functional properties of TPU NCs was performed by Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic mechanical thermal analyses (DMTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), water contact angle and water absorption tests. The results revealed that TPU NCs with the increasing hard segment content exhibit higher values of degree of microphase separation, melting temperature of the hard segments, degree of crystallinity, storage modulus (except for TPU NC-55), but lower thermal stability and hydrophobicity. TPU NC films were hydrophobic and their free surface energy was in the range from 17.7 to 24.9 mJ m-2. This work highlights how the composition of TPU NCs would affect their functional properties and provide an additional composition intended for designing advanced TPU NC materials for special biomedical applications. [ABSTRACT FROM AUTHOR]