This research has accomplished a comparative rheological test on the unmodified and nanoclay modified bitumen. The results show that compared to unmodified bitumen, the nanoclay modification leads to changes in rheological parameter by increasing stiffness and decreasing the phase angle hence; it can also reduce aging effect on bitumen. Further, the comparison of the rutting parameter (G*/sind) shows that the nanoclay modification could increase the rutting resistance of bitumen where the improvement is dependent upon the type and amount of nanoclay.The fatigue resistance parameter (G*sind) at the low to medium temperature shows that the nanoclay modification reduces the fatigue life, however, it exhibits the same fatigue life as that of the unmodified bitumen after a particular ageing condition.

Nanoclays are widely used in preparation of polymer clay nanocomposites. They are mostly prepared through cation exchange reaction between clay and cationic intercalants. Alkyl ammonium salts and alkyl amines are usually used as intercalants for the nanoclay preparation. Due to the toxicity of the intercalates, the current commercial nanoclays are not suitable for bio-applications. In the present report, a biological macromolecule (chitosan) was selected for the clay modification. The obtained bio-modified nanoclay can be used to prepare polymer-clay nanocomposites for various applications in biomedicine. In addition, this report comprises the first successful attempts to use a new approach for rapid preparation of chitosan-intercalated bentonite under green conditions. The conventional time-consuming manner (6-48 h) was replaced with a novel approach to quicken the reaction very considerably. XRD Studies exhibit that the clay galleries were increased from 12.34 to 16.45oA using a combination of ultrasound (30 min) - microwave (3 min) - irradiation.

Background & objectives: This study aims to assess the antibacterial efficacy of montmorillonite nanoclay modified with silver and bismuth nanoparticles against Escherichia coli, a common gram-negative bacterium known for causing gastrointestinal and extraintestinal infections. Methods: Methods: In this research, the initial steps for producing montmorillonite nanoclay included extracting bentonite from mines, crushing and grinding the raw material, and then sieving the resulting powder to obtain particles smaller than 74 μm. The nanoclay underwent optimization and was treated with silver and bismuth nanoparticles. The analysis involved electron microscopy, X-ray diffraction, laser diffraction for particle size assessment, and evaluation of quartz peak intensity to measure the effectiveness of the antibacterial nanoclay synthesis. The Minimum Inhibitory Concentration (MIC) was determined through agar dilution to assess its impact on E. coli viability in vitro. Results: Utilizing Results: Using montmorillonite particles smaller than 2 μm was effective in producing pharmaceutical nanoclay. The montmorillonite nanoclay with silver showed the highest efficacy against the standard E. coli strain, with a MIC value of 64 μg/mL. Following in effectiveness were the bismuth nanoparticle-modified nanoclay and the montmorillonite nanoclay, having MIC values of 128 and 512 μg/mL, respectively. Conclusion: The physical production method emerged as the safest and most efficient approach for pharmaceutical-grade nanoclay. Treating nanoclay with silver ions showed greater success compared to bismuth nanoparticle modification.

The weaknesses of the traditional asphalt cements produced by the refineries are the main factors in premature failure of asphalt pavements. One of the measures to prevent these failures is the modification of the asphalt using additives. A variety of materials have been used for modification, among which are polymers and nano materials, including nanoclays. As the effects of these two types have not been compared in the literature, this paper describes the results of an experimental work, in which the effects of a type of nanoclay and Styrene-Butadene-Styrene, SBS, on the properties of 60.70 penetration grade asphalt cement have been investigated. Different amounts of each additive have been added to the asphalt, and the properties of penetration grade, softening point, penetration index, dynamic viscosity, and the rheological properties including phase angle and complex dynamic modulus have been studied. The results show that, both the additives have a stiffening effect on the asphalt, which increase the strength against permanent deformation. However, the stiffening effect is dependent on the type of additive and the amount of them used for modification. The SBS polymer has a better effect for improving the resistance against permanent deformation.

Background and purpose: Natural organic matter in water resources (mainly caused by humic acid) leads to formation of THMs and HAAs. Removal of DBPs precursors from drinking water resources is the most important step to prevent from THMs formation. The aim of this study was to investigate the efficiency of modified nanoclay with EDTA and fresh nanoclay in adsorption of humic acid in aquatic solutions.Materials and methods: Characteristics and chemical structure of fresh and modified nanoclays were determined via scanning electronic microscope (SEM), BET, XRD, and FTIR techniques. HA concentration was determined by spectrophotometric method in 254 nm. Langmuir, Freundlich models and pseudo-first and pseudo second-order kinetics were used for adsorption isotherm and kinetics studies, respectively.Results: The XRD results showed that the distance between the layers increased after modification of nanoclay with EDTA. Also, BET analysis revealed that specific area of nanoclay increased from 13.02 to 28.36 m2/gr after modification. By decrease in pH the efficiency in removal of humic acid increased and in constant initial concentration of HA by increasing adsorbent dosage the adsorption capacity decreased. Adsorption of HA onto modified nanoclay and fresh nanoclay complies with Langmuir (R2=0.989) and Freundlich (R2=0.96), respectively. The pseudo-first order kinetic complies for both adsorptions.Conclusion: This study showed that in acidic condition the modified nanoclay has an appropriate efficiency on HA adsorption.

The purpose of this study was to remove nitrate ion using montmorillonites nanoclay modified with octa decy lamine functional group. In this study, nanoclay was first modified using octa decyl amine and the size and surface properties of this modified nanoparticle was investigated by scanning electron microscopy (SEM) and X-ray diffraction spectrum (XRD). In the next step, the nitrate ion adsorption process was investigated using adsorption model and by examining the effect of parameters of contact time, nitrate ion concentration, pH, and, adsorbent dosage on nitrate removal. Adsorption rate was evaluated by atomic absorption spectroscopy. The results showed that the correction of the nanoclay surface modified by the amine group increased the interlayer spacing from 7. 58 to 22. 91  A. The size of the modified nanoparticles was about 80-100 nm, which increased the active adsorbing sites by increasing nanoadsorbent surface. In the study of adsorption of nitrate ions, the maximum adsorption achieved at pH 5, the initial concentration of 100 mg/l, the contact time of 40 min, and 0. 7 g of nanoadsorbent. Studing the equilibrium isotherms, it was found that the adsorption process follows Langmuir and Freundlich isotherms. The kinetics of this process are consistent with the second-order kinetic model.

The effects of adding nanoclay to improve the thermal and mechanical properties of polypropylene (PP) copolymers grade (EPD60R) used in the pipe industry were investigated. To improve the dispersion of the nanoclay in the polymeric matrix, a 30 wt% of nanoclay master batch was first prepared by mixing PP matrix maleic anhydride PP oligomer (PP-g-MA) and Cloisite® 15A (C15A) nanoclay. The prepared master batch was used to produce nanocomposites with 2 and 5 wt% nanoclay. The nanocomposites were analyzed by XRD (X-ray diffraction), SEM (Scanning electron microscopy), DSC (Differential scanning calorimetry), TGA (Thermogravimetric analysis), and other mechanical tests. The XRD and SEM results indicated the occurrence of an intercalated layer structure in the nanocomposites. Thermal properties of the nanocomposites were investigated using DSC and TGA tests. The crystallinity of the 2 wt% nanoclay was improved by about 59. 23% in the nanoclay reinforced samples. As the content of nanoclay increased, the composite exhibited higher thermal degradation temperature. Performing a limiting oxygen index (LOI) test on the samples showed that the addition of nanoclay to the EPD60R matrix increased the flame retardancy by 12. 58%. The tensile modulus of the nanocomposites was improved compared to the pure polymer, while the elongation at break and at yield showed a reduction. To investigate the nanocomposite in pipe application, a pipe (external diameter 110. 8 and thickness 3. 65 mm) was manufactured in a special tube extruder machine with 2 wt% of C15A. Tests of the tube’ s physical and mechanical properties indicated that its ring stiffness increased by 25% compared to the pure PP.

The effect of a high-density polyethylene grafted amine alcohol (HDPE-g-DMAE) as compatibilizer on the mechanical, rheological and morphological characteristics of polyethylene/polyethylene post-consumer recycled blends (HDPE/rHDPE) reinforced with nanoclay was studied. Blends of HDPE with high rHDPE contents, more than 60% (wt) of rHDPE, were evaluated. HDPE bottles were manually separated from municipal solid waste, washed, grinded, and finally compounded at various concentrations with virgin HDPE and nanoclay. The effect of this HDPE-g-DMAE was compared with conventional polyethylene maleic anhydride (HDPE-g-MA) compatibilizer. FTIR characterization confirmed the formation of this HDPE-g-DMAE compatibilizer. The mechanical properties of uncompatibilized blends decreased with increasing rHDPE content, whereas these properties were significantly enhanced when HDPE-g-DMAE was used compared with HDPE-g-MA compatibilizer and with uncompatibilized blends. Scanning electron (SEM) micrographs of the fractured surfaces when using HDPE-g-DMAE showed improvement in the interfacial adhesion and interaction between recycled and virgin polyethylene. The nanocomposites compatibilized with PE-g-DMAE had better clay exfoliation–, intercalated structure compared to PE-g-MA-compatibilized nanocomposites. The novelty of this work is based on the use of PE-g-DMAE as a compatibilizer in HDPE/rHDPE/nanoclay composites with improved mechanical properties. This compatibilizer promoted the adhesion between recycled and virgin polymer phases in the blend and increased the interactions between compatibilizer and hydroxyl groups on the clay surface, as well as oxidized groups in the recycled polymer. This indicates that recycled postconsumer HDPE could replace, in larger proportions, part of the virgin HDPE for certain applications with better mechanical performance than uncompatibilized blends. This is an option to bring recycled plastics back into the market and increase the versatility of products manufactured with recycled polymers.