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Polyaniline (PANI) incorporating titanium dioxide (TiO2), silicon dioxide (SiO2) and zinc oxide (ZnO) were successfully synthesized via an ultrasonic-assisted in-situ chemical oxidative polymerization technique. This method significantly enhances the dispersion and interaction of metal oxides (MOs) within the PANI matrix. Detail analysis of the structural, morphological, thermal, and electrical properties of nanocomposites revealed substantial enhancements. XRD and FTIR results confirmed the successful incorporation of MOs into the PANI matrix, evidenced by the reduction in peak intensities. Morphological studies via FESEM highlighted the impact of MOs on the PANI microstructure, particularly the notable agglomeration of TiO2. DLS results demonstrated variations in particle size distributions, with SiO2 and ZnO contributing to reduced particle sizes, while TiO2 increased the average particle size due to aggregation. Thermal analysis via TGA and DSC revealed enhanced thermal stability of the nanocomposites compared to pure PANI, with SiO2/PANI exhibiting the highest stability. Electrical conductivity measurement demonstrated that the SiO2/PANI nanocomposite exhibited the highest performance, with a conductivity of 0.43 S/cm, attributed to the effective interaction between SiO2 and PANI which facilitates electron transfer. Electrochemical studies, including Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS), further confirmed the superior electrochemical performance of the SiO2/PANI nanocomposite, showing the highest current response and the lowest charge transfer resistance. These findings highlight the novel synthesis method and the enhanced properties of MO/PANI nanocomposites, presenting significant advancements for advanced technological applications. [ABSTRACT FROM AUTHOR]

The addition of metals or metal oxides (MOs) into polypyrrole (PPy) could facilitate the effective incorporation of the features of a parent component into novel nanocomposites. As such, this present study used in-situ ultrasonic-assisted chemical oxidative polymerisation (in-situ UA-COP) to synthesise MO-PPy nanocomposites using titanium dioxide (TiO2), zinc oxide (ZnO), and silicone dioxide (SiO2). The impact of MOs on the structural, morphological, thermal and electrical characteristics of the fabricated nanocomposites was then methodically analysed. The nanocomposites' structural and chemical constitutions were ascertained by way of X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The MOs were incorporated via non-covalent bonds into the PPy matrix, without significantly affecting the PPy matrix. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses demonstrated that TiO2-PPy was the most thermally stable, rending it is ideal for use in reactions that require high resistance to temperature. It also had the highest electrical conductivity (2.48 S/cm), which could be attributed to the conductive channels that the MO nanoparticle interconnections formed within the polymer matrix. This in-depth investigation serves to disclose the effect of different MOs on the characteristics of PPy nanocomposites. The findings of this present study also highlight the potential applications of the produced PPy nanocomposites in different fields, especially for use in sensors. [ABSTRACT FROM AUTHOR]

The primary goals of human civilization are sustainable growth and restoration of the ecosystem. Currently, the continuous release of effluents containing heavy metals from tanneries, and the mining, printing, and pharmaceutical industries into the aquatic environment has become a serious issue. Chromium (Cr) and mercury (Hg) pose a major threat to human beings. Several techniques have been employed to mitigate this threat, including adsorption, electrolysis, chemical precipitation, desalination, reverse osmosis, ion exchange, membrane filtration, and photocatalysis. However, photocatalysis is known for its cost-effectiveness and green aspects in the removal of heavy metal ions from solutions. Over the last few decades, there has been a growing interest among researchers worldwide to study this technique. Numerous materials, including conducting polymers (CPs), have been utilized for the removal of heavy metal ions from wastewater/aqueous solutions. Polyaniline (PANI)-based nanocomposites are effective photocatalysts for the removal of various types of heavy metal ions from wastewater/aqueous solutions. Despite its potential, several factors affect the removal efficiency, such as irradiation levels and the type of PANIbased nanocomposite used. Further research is needed to address these challenges and improve the stability and reusability of PANI-based photocatalysts. Given the available water resources in the real world, it is critical that in-depth research be conducted into PANI-based photocatalysts, and the stability and reusability of such catalysts and achieving the primary goals of human civilization, namely sustainable growth and ecosystem restoration. [ABSTRACT FROM AUTHOR]

Alkaline–surfactant–polymer (ASP) flooding, a recognized method for oil recovery, encounters limited use due to its expense. In addition, ASP's best composition and injection sequence still remains uncertain today. This study explores conventional ASP flooding using PT SPR Langgak's special surfactants, simulating Langgak oilfield conditions in Sumatra, Indonesia. By comparing the outcomes of this flooding technique with that of starch-assisted ASP performed in another study, the benefits of adding starch nanoparticles to flooding are evident. Nano-starch ASP increased oil recovery by 18.37%, 10.76%, and 10.37% for the three configurations investigated in this study. Water flooding preceded ASP flooding, and flooding operations were carried out at 60 °C. This study employed sodium hydroxide (NaOH), sodium carbonate (Na2CO3), and specialized surfactants from PT SPR. The adopted polymer is solely hydrolyzed polyacrylamide (HPAM) at 2000 ppm. Starch nanoparticles underwent comprehensive characterization and focused more on charge stability. Purple yam nanoparticles (PYNPs) exhibited remarkable stability at −36.33 mV, unlike cassava starch nanoparticles (CSNPs') at −10.68 mV and HPAM's at −27.13 mV. Surface properties affect interactions with fluids and rocks. Crystallinity, a crucial characterization, was assessed using Origin software 2019b. CSNPs showed 24.15% crystallinity, surpassing PYNPs' 20.68%. Higher crystallinity benefits CSNPs' thermal stability. The amorphous behavior found in PYNPs makes them less suitable if applied in harsh reservoirs. This research correlated with prior findings, reinforcing starch nanoparticles' role in enhancing oil recovery. In summary, this study highlighted conventional ASP flooding using HPAM as the sole polymer and compared it with three formations that used two starch nanoparticles included with HPAM, assessing their impact on charge stability, crystallinity, and recovery rate to emphasize their importance in the oil recovery industry. Starch nanoparticles' benefits and limitations guided further investigation in this study. [ABSTRACT FROM AUTHOR]

This study aimed to address the challenges faced by mature oilfields in extracting substantial oil quantities. It focused on improving the efficiency of alkaline–surfactant–polymer (ASP) flooding technique, which is a proven tertiary recovery technology, to overcome scaling issues and other hindrances in its large-scale implementation. Appropriate materials and their suitable concentrations were selected to enhance the ASP flooding technique. Special surfactants from Indonesia were introduced to improve the interfacial tension reduction and wettability alteration. Reservoir rock model that resembling Langgak oilfield in Sumatra was utilized, and low-salinity water was employed to mimic the oilfield conditions. Starches derived from cassava nanoparticles (CSNPs) and purple yam nanoparticles (PYNPs) were combined separately with conventional hydrolyzed polyacrylamide (HPAM) polymer to enhance its performance. Sodium hydroxide and sodium carbonate were used as alkaline in final ASP formula. It was demonstrated from this research that only two combinations of ASP formulations have led to improved oil recovery. One combination utilizing PYNPs resulted in 39.17% progressive recovery, while the other combination incorporating CSNPs achieved 35% incremental oil recovery. The ASP combination that resulted in recovery rate of 39.17% was composed of sodium hydroxide (NaOH) at a concentration of 1.28 wt.%, PSC EOR 2.2 (0.98 wt.%), and a combined polymer consisting of HPAM (0.2 wt.%) and PYNPs nano-starch (0.6 wt.%). The second combination led to 35% recovery rate and involved NaOH also at concentration 1.28 wt.%, PSC HOMF (0.63 wt.%), and a combined polymer comprising from HPAM (0.2 wt.%) and CSNPs nano-starch (0.8 wt.%). These findings of this study highlighted the potential of this modified ASP flooding to enhance oil recovery in mature oilfields, thereby offering valuable insights for oil industry. [ABSTRACT FROM AUTHOR]

Epoxy resin is commonly used in the oil and gas industry due to its excellent toughness, low shrinkage, good adhesive strength, and relatively good thermal resistance. It is used for water shutoff, zonal isolation, cementing, enhanced oil recovery, and preventing leakage in wells. This paper reviews the chemistry aspect of using an epoxy resin system as a sealant to prevent well leakage and it offers insights into the chemistry of the epoxy resin system, as applied in previous studies. The paper also unveils the reasons for the application of this system from the chemistry perspective, allowing this aspect to be better understood. Success in the investigated cases depended on the formulation design. The epoxide and hydroxyl functional groups have been found to contribute substantially to the excellent performance of the sealant system. Furthermore, the amine curing agent triggers the abrupt reaction of the oxirane ring to stabilise when the cured sealant is perfectly applied. Based on the findings, it is suggested that other types of epoxies, namely epoxidised oils, require further study. Finally, in terms of safety and sustainable energy, it is suggested that more curing agent and diluent studies are undertaken. [ABSTRACT FROM AUTHOR]

Significant amounts of oil remain in the reservoir after primary and secondary operations, and to recover the remaining oil, enhanced oil recovery (EOR) can be applied as one of the feasible options remaining nowadays. In this study, new nano-polymeric materials have been prepared from purple yam and cassava starches. The yield of purple yam nanoparticles (PYNPs) was 85%, and that of cassava nanoparticles (CSNPs) was 90.53%. Synthesized materials were characterized through particle size distribution (PSA), Zeta potential distribution, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The performance of PYNPs in recovering oil was better than CSNPs, as found from the recovery experiments. Zeta potential distribution results confirmed the stability of PYNPs over CSNPs (−36.3 mV for PYNPs and −10.7 mV for CSNPs). The optimum concentration for these nanoparticles has been found from interfacial tension measurements and rheological properties, and it was 0.60 wt.% for PYNPs and 0.80 wt.% for CSNPs. A more incremental recovery (33.46%) was achieved for the polymer that contained PYNPs in comparison to the other nano-polymer (31.3%). This paves the way for a new technology for polymer flooding that may replace the conventional method, which depends on partially hydrolyzed polyacrylamide (HPAM). [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) nanoparticles are reliable conducting polymers with many industrial applications. Nevertheless, owing to disadvantages in structure and morphology, producing PPy with high electrical conductivity is challenging. In this study, a chemical oxidative polymerization-assisted ultra-sonication method was used to synthesize PPy with high conductivity. The influence of critical sonication parameters such as time and power on the structure, morphology, and electrical properties was examined using response surface methodology. Various analyses such as SEM, FTIR, DSC, and TGA were performed on the PPy. An R2 value of 0.8699 from the regression analysis suggested a fine correlation between the observed and predicted values of PPy conductivity. Using response surface plots and contour line diagrams, the optimum sonication time and sonication power were found to be 17 min and 24 W, respectively, generating a maximum conductivity of 2.334 S/cm. Meanwhile, the model predicted 2.249 S/cm conductivity, indicating successful alignment with the experimental data and incurring marginal error. SEM results demonstrated that the morphology of the particles was almost spherical, whereas the FTIR spectra indicated the presence of certain functional groups in the PPy. The obtained PPy with high conductivity can be a promising conducting material with various applications, such as in supercapacitors, sensors, and other smart electronic devices. [ABSTRACT FROM AUTHOR]

The use of fluidization assistance can greatly enhance the fluidization hydrodynamics of powders that exhibit poor fluidization behavior. Compared to other assistance techniques, pulsed flow assistance is a promising technique for improving conventional fluidization because of its energy efficiency and ease of process implementation. However, the inlet flow configuration of pulsed flow can significantly affect the bed hydrodynamics. In this study, the conventional single drainage (SD) flow strategy was modified to purge the primary flow during the non-flow period of the pulse to eliminate pressure buildup in the inlet flow line while providing a second drainage path to the residual gas. The bed dynamics for both cases, namely, single drainage (SD) and modified double drainage (MDD), were carefully monitored by recording the overall and local pressure drop transients in different bed regions at two widely different pulsation frequencies of 0.05 and 0.25 Hz. The MDD strategy led to substantially faster bed dynamics and greater frictional pressure drop in lower bed regions with significantly mitigated segregation behavior. The spectral analysis of the local and global pressure transient data in the frequency domain revealed a pronounced difference between the two flow strategies. The application of the MDD inlet flow strategy eliminated the disturbances from the pulsed fluidized bed irrespective of the pulsation frequency. [ABSTRACT FROM AUTHOR]

As the world strives for sustainable development, renewable energy emerged as one of the crucial energy resources for daily consumption. Hydrogen is well known as a new renewable source that is clean and regarded to be low cost. Hence, the method to produce hydrogen in the cleanest way is in pursuit. Thermodynamic modelling using Gibbs free energy minimization is widely used in predicting various products including hydrogen. In this study, steam reforming reaction of methane combined with glycerol, a co-product from biodiesel production was performed to determine the hydrogen production trend as well as other possible products (CO, CO2, C, CH4, C2H4 and C2H6. The equilibrium composition was determined at reaction temperatures 573 K-1,273 K, pressure 1-5 bars and molar ratios glycerol-methane-steam (GMS) 1:1:1 - 12:1:1, 1:3:1-1:12:1, 1:1:3 - 1:1:12. The optimum process parameters for H2 production was attained at 1,023 K with 1 bar pressure and the molar ratios for GMS at 1:1:1. It was discovered that greater GMS ratio instantly reduced the formation of hydrogen. The knowledge from the thermodynamic analysis of glycerol-methane steam reforming is a great method to aim for highest hydrogen yield and at the same time lowering the tendency of coking process that could poison the catalyst. [ABSTRACT FROM AUTHOR]

Nanostarch is unique in that it is highly soluble, thermally stable, non-toxic and inexpensive. Hence, it is utilized in numerous well-established applications, including drug delivery, cosmetics, textiles, foods, and enhanced oil recovery (EOR). These applications take advantage of the special functions that can be achieved through modifications to the structure and properties of native starch. The most common method for the preparation of nanostarch with a relatively higher crystallinity and stability is acid hydrolysis. Technically, the properties of nanostarch are highly dependent on several factors during the hydrolysis process, such as the acid, concentration of acid, reaction time, reaction temperature, and source of starch. The production of nanostarch with desired properties requires a detailed understanding on each of the factors as they are inevitably affected the physical and chemical properties of nanostarch. Hence, it is vital to incorporate optimization technique into the production process to achieve the full potential of nanostarch. Therefore, the current review comprehensively elaborates on the factors that affect acid hydrolysis as well as the optimization techniques used in the preparation of nanostarch. [ABSTRACT FROM AUTHOR]

Bed collapse experiments provide vital information about fluidized bed hydrodynamics. In this study, the region-wise bed collapse dynamics of glass beads, titania (TiO2), and hydrophilic nanosilica (SiO2) particles with widely different voidages (ε) of 0.38, 0.80, and 0.98, respectively, were carefully investigated. These particles belonged to different Geldart groups and exhibited varied hysteresis phenomena and fluidization indices. The local collapse dynamics in the lower, lower-middle, upper-middle, and upper regions were carefully monitored in addition to the distributor pressure drop to obtain greater insight into the deaeration behavior of the bed. While the collapse dynamics of glass beads revealed high bed homogeneity, the upper middle region controlled the collapse process in the case of titania due to the size-based segregation along the bed height. The segregation behavior was very strong for nanosilica, with the slow settling fine agglomerates in the upper bed regions controlling its collapse dynamics. The collapse time of the upper region was 25 times slower than that of the lower region containing mainly large agglomerates. The spectral analysis confirmed the trend that was observed in the pressure transients. The clear presence of high frequency events at 20 and 40 Hz was observed in the nanosilica due to agglomerate movements. The residual air exiting the plenum was strongly affected by the bed voidage, being lowest for the nanosilica and highest for the glass beads. [ABSTRACT FROM AUTHOR]

The commercial utilization of bulk nanosilica is widespread in concrete, rubber and plastics, cosmetics and agriculture-related applications, and the market of this product is projected to exceed USD 5 billion by 2025. In this investigation, the local dynamics of a nanosilica bed, excited with sinusoidal acoustic waves of different frequencies, were carefully monitored using sensitive pressure transducers to obtain detailed insights into the effectiveness of sound waves as a means of energy transport inside the bed. The evolution of wave patterns and their frequency and power distributions were examined both in the freeboard and in the static bed. These results were compared with those obtained by using an empty column. The acoustic frequency strongly affected the signal power. The average power of the acoustic signal in the freeboard region was twice higher than that for the empty column, whereas the same (power) ratio decreased to approximately 0.03 inside the bed for 300 Hz. However, at 360 Hz, the power ratio was substantially lower at 0.24 and 0.002 for the freeboard and the granular bed, respectively, thereby indicating tremendous attenuation of acoustic waves in the granular media at all frequencies. [ABSTRACT FROM AUTHOR]

The enhanced oil recovery (EOR) techniques are employed to recover more oil from mature reservoirs following the primary and secondary stages of oil production. Polymer flooding is a chemical EOR method that involves the addition of polymer molecules to a treated area to improve its water viscosity and sweep efficiency, and to accelerate oil production. The increased water viscosity will reduce the mobility ratio of the injected fluid to the reservoir fluid. Polymer flooding is most effective when applied in the early stages of a water flood while the mobile oil saturation is still high. The polymers used in polymer flooding are divided into synthetic polymers and biopolymers. Unfortunately, synthetic polymers are susceptible to brine formation and high temperatures. On the other hand, biopolymers have a more rigid chemical chain structure making them more resistant to high temperatures (about 135°C) and salinity (about 220 g/L). This review presents a comprehensive discussion of the use of polymers for EOR applications. First, a summary and explanation are given of the structure and characterization of polymers. Subsequently, the general screening criteria for polymer flooding are highlighted. Then, the properties of synthetic and natural polymers and their application in EOR are presented. Finally, the limitations of this study and suggestion for future work on polymers in EOR are explained. [ABSTRACT FROM AUTHOR]

Over the years, there has been an emphasis on the improvement of novel materials for photocatalytic processes for practical application in treating wastewater. In this sense, the ultrasonic‐assisted in‐situ chemical polymerization route was used to synthesize polypyrrole‐multiwall carbon nanotubes (PPy‐MWCNTs) nanocomposites. The transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV–vis) analysis were employed to study the impact of MWCNTs on the properties of PPy. TEM showed that the PPy‐MWCNTs nanocomposites consist of spherical PPy with 80 nm particle size, while the MWCNTs showed inner and outer diameters of 7 nm and 13 nm, respectively. XRD analysis showed that the crystallinity of the PPy increased with MWCNTs loading. The potential of PPy‐MWCNTs nanocomposites as photocatalysts was evaluated via the photodegradation of rhodamine B (RhB) and methylene blue (MB) dyes. The photodegradation efficiency was found to have improved with increasing MWCNTs loading. Almost 99.36% and 78.30% of RhB and MB dye degradation were achieved after 35 min of reaction for the highest loading of MWCNTs. The remarkable nanocomposite photocatalytic activity was attributed to the optical bandgap energy (Eg) reduction with the addition of MWCNTs. These results foreshadow the potential use of the PPy‐MWCNTs nanocomposites for water purification. [ABSTRACT FROM AUTHOR]

Although the world is turning to renewables as a clean alternative source of energy, reliance on oil is expected to continue for more decades. Enhanced oil recovery (EOR) is an efficient way to recover oil after implementing initial methods. Alkali–surfactant–polymer flooding (ASP) has acquired much interest together with nano-fluid that involves using nano metallic oxides in EOR. Nanoparticles have proved their effectiveness in reducing interfacial tension at the interface between the oil and water and have been used with water, polymers, surfactants, alkaline, or a mixture of these components. Incremental oil recovery from applying ASP floods has exceeded 20% OOIP, and this is considered promising performance for unlocking oil reserves for many years to come. Despite that, ASP flooding nowadays faces big challenges presented by fluctuating oil prices, scaling and corrosion of the lifting system, and the formation of relatively strong emulsions that need high-cost treatment after oil production. This review emphasizes ASP flooding and the ASP flooding and the implementation of nanoparticles in extracting more oil using different chemical agents and sheds light on improving the recovery ratio. This study also explains the challenges that face each process and the steps that should be taken in order to overcome these challenges. [ABSTRACT FROM AUTHOR]

Effects of various molar ratios of monomer (aniline), oxidant (ammonium peroxydisulfate), and dopant (hydrochloric acid) on the polymerization of polyaniline (PANI) were investigated using direct ultrasonic irradiation technique. The effects of varying molar ratio of dopant and oxidant on the structural stability, morphology, and electrical conductivity of the prepared PANI were studied. Firstly, a scheme derived from electrical conductivity point of view, by varying the molar ratio of ammonium peroxydisulfate (APS). As the molar ratio of APS to aniline (ANI) varied from 0.1 to 1.25, the conductivity of PANI reached a maximum of 0.24 S/cm at a ratio of 1. Thereafter, by fixing the optimized molar ratio of APS and aniline the molar ratio of hydrochloric acid (HCl) was varied. The conductivity of PANI increased with an increase of HCl concentration and reached a maximum of 0.5 S/cm at an HCl concentration of 2 M. Finally, the formation mechanism for polymerization of PANI were discussed using Fourier transform infrared spectra, ultraviolet–visible spectra, nuclear magnetic resonance spectroscopy, and X‐ray diffraction spectroscopy. The final product is in protonated form, possessing structural stability and electrically conductive. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) has unique features such as easy synthesis, environmental stability, and high electrical conductivity (approximately 105 S/cm and even >380 S/cm) for bulk and thin‐film materials. Thus, PPy is applied in numerous well‐established applications, such as in sensors, supercapacitors, and resonators. These applications take advantage of the unique properties achieved through the structure and properties of PPy. This article comprehensively elaborates the methods used to synthesize conductive PPy, along with the important factors affecting its conductivity. Emphasis is given to versatile and basic approaches that enable control of the microstructural features that eventually determine PPy conductivity. Despite the intensive research in this area, no previous study has presented all possible relevant information about PPy fabrication and the important factors influencing its electrical conductivity. [ABSTRACT FROM AUTHOR]

Recycled polypropylene/polyaniline/graphene nanoplatelets (rPP/PANI/GNPs) nanocomposites were fabricated via ultrasonic-assisted single-screw extruder at 150–170 °C with a rotating screw speed of 50 rpm. The ultrasonic wave frequency and power supply were kept constant at a frequency of 20 kHz and 6 kW, respectively. The composition of the polymer nanocomposites used in this study was 92 wt.% rPP and 8 wt.% PANI, denoted as rPP/PANI. The effects of GNPs loadings (0.5, 1.5, and 3.0 parts per hundred resin (phr)) on the structural, morphological, thermal, and electrical properties on the nanocomposites were systematically evaluated. The X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) showed the presence of GNPs characteristics at 26.5°, 42.40°, 54.51°, and interactions between GNPs and rPP/PANI nanocomposites at different GNPs loadings. The compatibility of GNPs in rPP/PANI nanocomposites was confirmed by the morphological study, which showed to an enhancement in the electrical properties of the nanocomposites. The results also showed that the incorporation of 3 phr GNPs into rPP/PANI nanocomposites resulted in a lower degree of crystallinity of about 20.8% and a higher electrical conductivity of about 4.1 × 10–1 S cm−1. The current work paves a way towards understanding how to effectively enhance the electrical conductivity of rPP/PANI nanocomposites using GNPs, leading to potential use in electronic applications. [ABSTRACT FROM AUTHOR]

Ascorbic acid was used for the first time to synthesize cellulose nanoparticles (CNP) extracted from okra mucilage. The physical properties of the CNP including their size distribution, and crystalline structures were investigated. The rheological properties of the cellulose nanofluid (CNF) were compared with the bulk okra mucilage and commercial polymer xanthan. The interfacial properties of the CNF at the interface of oil-water (O/W) system were investigated at different concentrations and temperatures. The effects of the interaction between the electrolyte and ultrasonic were determined. Core flooding experiment was conducted at reservoir condition to justify the effect of the flow behaviour and disperse phase behaviour of CNF on additional oil recovery. The performance of the CNF was compared to conventional EOR chemical. The combined method of ultrasonic, weak-acid hydrolysis and nanoprecipitation were effective in producing spherical and polygonal nanoparticles with a mean diameter of 100 nm, increased yield of 51% and preserved crystallinity respectively. The zeta potential result shows that the CNF was stable, and the surface charge signifies long term stability of the fluid when injected into oil field reservoirs. The CNF, okra and xanthan exhibited shear-thinning and pseudoplastic behaviour. The IFT decreased with increase in concentration of CNF, electrolyte and temperature. The pressure drop data confirmed the stability of CNF at 120°C and the formation of oil bank was enough to increase the oil recovery by 20%. CNF was found to be very effective in mobilizing residual oil at high-temperature high-pressure (HTHP) reservoir condition. The energy and cost estimations have shown that investing in ultrasonic-assisted weak-acid hydrolysis is easier, cost-effective, and can reduce energy consumption making the method economically advantageous compared to conventional methods. [ABSTRACT FROM AUTHOR]

A novel sonochemical method has been applied to prepare Polyaniline (PANI) from aniline monomers. PANI was synthesized via ultrasonic irradiation (U.I) by varying the sonication (reaction) time. Surface morphology and electrical conductivity were studied using FESEM and Four-probe conductivity meter and structural properties were examined using FT-IR and UV-VIS. The presence of characteristic bonds of PANI was observed from FTIR spectroscopy technique. The findings of this study reveal the importance of sonication time in shaping the morphology, particle sizes and electrical conductivity of the PANI. The morphology of the generated PANI indicated granular structure. On the other hand, the electrical conductivity of the nanocomposite increased up to 1.78 S/cm at 30 min of sonication and then decreased with further increase in sonication time. Sonochemical synthesis route is a multifaceted technique using which nanostructured materials with different physical and chemical characteristics can by produced. This can be achieved by just varying the treatment condition (e.g., ultrasonic irradiation time, amplitude, temperature) during sonication. Therefore, this study provides the optimized sonication time for PANI synthesis. The output of this research clearly shows that, ultrasonication is a one of the fast, versatile, emerging, and promising non-destructive green technology which still needs to be understood completely. [ABSTRACT FROM AUTHOR]

In recent years, pharmaceutical compound has been detected in small concentration in our surface and ground water. This detection raises a lot of concern as is it reported that pharmaceutical compound can bring adverse effect to the environment even at low concentration. Besides that, there is a growing fear that this compound will eventually end up in human drinking water, thus effecting human health. This prompt a lot of research on the removal method for this particular compound. Adsorption is seen as the most viable option because of its high efficiency, low cost and it is environmentally friendly. In this study, the adsorbent used is carbon black derived from tyre waste via pyrolysis at 800 °C. The carbon black was treated with 6 M of nitric acid (HNO3) at 90 °C for 0.5 h before being subjected to thermal treatment at 600 °C for 1 h. The response of the adsorption study is the removal of aspirin. There were five adsorption parameters that were varied in this study which are the contact time (until equilibrium), initial pH of aspirin solution (pH 3, pH 7, pH 11), temperature (30, 50, 70 °C), initial concentration (10-100 mg/L) and adsorbent dosage (0.1 g, 0.5 g, 1.0 g). The best removal capacity obtained was 40.40 mg/g of aspirin at pH 3, temperature of 30 °C, 100 mg/L initial concentration and 0.02 g adsorbent dosage. [ABSTRACT FROM AUTHOR]

This work was aimed at evaluating the characteristics of activated carbons derived from rubber seed shell through physical activation using CO2 for phenol removal. Two activated carbons were obtained at different retention times of 30 min (AC1) and 90 min (AC2) at fixed temperature of 900 °C. Activated carbons were characterized for specific surface area, surface functional groups and morphology. The values of specific surface area were recorded as 852 m²/g and 606 m²/g for AC2 and AC1. AC2 shows a higher phenol removal capacity of 302 mg/g than AC1 (112 mg/g) that is directly related to the specific surface area of activated carbons. The equilibrium data fitted well to the Langmuir isotherm, suggesting monolayer coverage of phenol molecules on the homogeneous surface of activated carbons. The kinetics data obeyed pseudo-first-order model, indicating the external diffusion as the rate-limiting step in adsorption. [ABSTRACT FROM AUTHOR]

ABSTRACT The effects of natural rubber (NR) on the mechanical, thermal, and morphological properties of multiwalled carbon nanotube (CNT) reinforced poly(lactic acid) (PLA) nanocomposites prepared by melt blending were investigated. A PLA/NR blend and PLA/CNT nanocomposites were also produced for comparison. The tensile strength and Young's modulus of PLA/CNT nanocomposites improved significantly, whereas the impact strength decreased compared to neat PLA. The incorporation of NR into PLA/CNT significantly improved the impact strength and elongation at break of the nanocomposites, which showed approximately 200% and 850% increases at 20 wt % NR, respectively. However, the tensile strength and Young's modulus of PLA/NR/CNT nanocomposites decreased compared to PLA/CNT nanocomposites. The morphology analysis showed the homogeneous dispersion of NR particles in PLA/NR/CNT nanocomposites, while CNTs preferentially reside in the NR phase rather than the PLA matrix. In addition, the incorporation of NR into PLA/CNT lowered the thermal stability and glass-transition temperature of the nanocomposites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44344. [ABSTRACT FROM AUTHOR]

In this study, recycled polypropylene/empty fruit bunch (rPP/EFB) composites were produced by melt blending technique. Further, varying content of polypropylene (PP), ethylene vinyl acetate (EVA) and polyamide-6 (PA6) was incorporated to rPP/EFB composites. The effect of varying contents of PP, EVA and PA6 on the mechanical and thermal properties of the recycled rPP/EFB composites was studied. The morphology of the prepared composites were examined by scanning electron microscope (SEM). It was found that the mechanical properties improved when PP and PA6 were incorporated in the rPP/EFB composite. The mechanical results were supported by SEM study. The Differential Scanning Calorimetry results revealed improvements in the melting temperature of rPP/EFB/EVA and rPP/EFB/PA6 composites. Further, incorporation of various polymers also improved the thermal stability of the composites, as shown by the thermogravimetric analysis. The rPP/EFB/PP composite exhibited the best mechanical properties and rPP/EFB/EVA composite exhibited better thermal properties. Whereas, rPP/EFB/PA6 composite showed improvement in both thermal and mechanical properties. [ABSTRACT FROM AUTHOR]

In this study, we have attempted to explain the influence of secondary filler on the dispersion of carbon nanotube (CNT) reinforced high density polyethylene (HDPE) nanocomposites (CNT/HDPE). In order to understand the mixed-fillers system, Montmorillonite (MMT) in addition with Maleic anhydride grafted high density polyethylene (PE-g-MA) was added to CNT/HDPE nanocomposites. It was followed by investigating their effect on the thermo-mechanical, rheological and morphological properties of the aforesaid nanocomposite. Incorporation of 3 wt% each of MMT and PE-g-MA into CNT/HDPE nanocomposites resulted to the increased values for the tensile and flexural strength (32 % increase in both), as compared to the pure HDPE matrix. The thermal analysis result showed improved thermal stability of the formulated nanocomposites. The initial decomposition temperature ( T) for such nanocomposite with 9 wt% of MMT and 3 wt% of PE-g-MA reached to 296 °C from 265 °C ( T for neat HDPE matrix). Addition of MMT to CNT/HDPE nanocomposites also increased the rheological properties indicating a dominating elastic response. A significant increase in loss, storage modulus and complex viscosity was observed upon addition of PE-g-MA, whereas Tan δ was found to be reduced. This might be due to better interfacial adhesion between MMT and HDPE phases that attributes to the elastic dominance. Improvement in dispersion of CNT upon addition of MMT and PE-g-MA was further supported by the morphological analysis. Transmission electron microscopy (TEM) images revealed that larger aggregates of CNTs were disappeared upon addition of these two components leading to the enhancement of thermo-mechanical properties for such composites. [ABSTRACT FROM AUTHOR]

Researchers have shown that techniques such as microwave-assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction developed for extraction of valuable components from plants and seed materials have been successfully used to effectively reduce the major shortcomings of the traditional method such as Soxhlet extraction. These include shorter extraction time, increase in yield of extracted components, decrease in solvent consumption, and improvement of the quality of extracts. This review presents a detailed description of the principles and mechanisms of the various extraction techniques for better understanding and summarizes the potential of these techniques in the extraction of oil from plants and seed materials. Discussions on some of the parameters affecting the extraction efficiency are also highlighted, with special emphasis on supercritical fluid extraction. A comparison of the performance of traditional Soxhlet extraction with that of other extraction techniques is also presented. [ABSTRACT FROM AUTHOR]

This review presents recent research advances in defining the curing and thermal characteristics, mechanical properties and appropriate processing techniques of thermoset resin derived from vegetable oils. Vegetable oil is the latest alternative found to replace the dependence on petroleum-based synthetic resin. Petroleum based resin reinforced with synthetic fiber composite is unbiodegradable, cannot be reused and recycled. Thus, it is very valuable to replace the dependance petroleum based resin to renewable source which contributes to green environment. However, biocomposites synthesized from vegetable oil-based resin matrix, reinforced with natural fiber, have some limitations. The properties are differentiated based on the type of vegetable oil. Modifying the fatty acid chain and applying nanoclay in composites as filler, helps to improve some properties due to the addition of vegetable oil in the resin system. Within this contribution, special emphasis was placed on a broad-brush approach over the potential opportunities concerning the use of renewable feedstock, such as modification of soybean oil, linseed oil, and nahar oil in thermoset resin. This review is focusing on investigating the approaches that have been proposed to produce bioresin and bio-based nanocomposites. [ABSTRACT FROM AUTHOR]

The objective of this study is to develop a green composites based on recycled polypropylene (rPP)/recycled polyamide 6 (rPA6) reinforced with kenaf. The investigations were carried out by collecting rPP from the nearest landfill and rPA6 was prepared by re-extrusion and composites preparations were obtained using a twin screw extruder and injection moulding. The rPP/rPA6 composition was selected in a ratio of 70/30 with compositions of kenaf from 10-30 wt.%. Tensile, flexural and impact tests were conducted to investigate the mechanical properties. The composites thermal properties, processing behaviour and morphological study were also investigated. Beside the decrement in impact properties other mechanical properties of the composites were improved upon as the compositions of kenaf were increased. A difficulty resulted in processing the composites using injection moulding machine as the melt flow index values increased. Scanning Electron Microscopy (SEM) micrographs showed an improvement in the dispersion of kenaf in the matrix when kenaf compositions were increased. The overall results showed the best composition of kenaf was at 30 wt. %. [ABSTRACT FROM AUTHOR]

The objective of this research is to investigate the effect of incorporating montmorillonite (MMT) on the mechanical, morphological, rheological, and thermal properties of recycled poly(ethylene terephthalate) (rPET) and high-density polyethylene (HDPE) nanocomposites. The MMT contents in 90:10 rPET/HDPE and 70:30 rPET/HDPE ranged from 1 to 5 wt.%. rPET/HDPE nanocomposites were prepared by using a single screw extruder, and injection molded to prepare mechanical test specimens. The samples underwent rheological tests by using a capillary rheometer, and the morphology of the nanocomposites was investigated by scanning electron microscopy (SEM). The thermal stability of the nanocomposites was tested using thermogravimetric analysis (TGA). The results showed that MMT acts as compatibilizing agent and improves phase dispersion and interfacial adhesion in the nanocomposites. The maximum tensile strength was found at 3 and 1 wt.% of MMT for the 90:10 and 70:30 rPET/HDPE blends. However, the tensile modulus decreased significantly with the incorporation of MMT. The impact strength for both the 90:10 and 70:30 blends reached a maximum at 3 wt.% and started to decrease beyond 3 wt.%. The incorporation of MMT increased the shear viscosity of the 90:10 and 70:30 blends, which reached a maximum value at 3 and 1 wt.%. SEM micrographs showed a good interaction of MMT that improved the adhesion between the two phases of blends and led to an increase in the mechanical properties of rPET/HDPE nanocomposites. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate the effect of incorporation of maleic anhydride grafted acrylonitrile-butadiene-styrene (ABS-g-MAH) on rheological properties of PA6/ABS blends. Flow properties of the blends were examined by dynamic and capillary rheometers. The dynamic rheological analyses showed an increase in complex viscosity with the incorporation of a compatibilizer. The reduction of tan δ peaks showed enhanced interfacial interaction between PA6 and ABS phase, which resulted in the enhancement of melt strength. The power law index analysis showed that 1.5 wt.% resulted in minimumnand maximumKvalue for the blends while still retaining the pseudoplastics behavior necessary for plastics processing and prediction for the end use performance of the PA6/ABS blends. [ABSTRACT FROM AUTHOR]

Polyamide-6 (PA6), acrylonitrile-butadiene-styrene (ABS), and their blends are an important class of engineering thermoplastics that are widely used for electronic and automotive industries. Many efforts have been made to improve the properties of both pure components and the blends. It was for this reason that the mechanical and rheological properties of PA6/ABS blend systems compatibilized by acrylonitrile-butadiene-styrene--maleic anhydride was studied. Short glass fiber was also used to enhance the compatibilized blends. The systems were prepared using a twin screw extruder. The specimens for mechanical test were molded using injection molding. The compatibilized blends showed higher mechanical properties compared to uncompatibilized blend. However, the impact strength reduced with the introduction of short glass fiber in the blends. The processing properties of the materials have been investigated using dynamic rheometer. The rheological measurements confirmed the increased in interaction between the blend components with the incorporation of compatibilizer. The incorporation of short glass fiber (SGF) into the compatibilized blends increased the storage and loss modulus as well as the viscosity of the blends. [ABSTRACT FROM AUTHOR]

Biodiesel is a promising renewable energy option that significantly reduces the emission of greenhouse gases and other toxic byproducts. However, a major challenge in the industrial scale production of biodiesel is the desired product purity. To this end, reactive distillation (RD) processes, which involve simultaneous removal of the byproduct during the transesterification reaction, can drive the equilibrium towards high product yield. In the present study, we first optimized the heat exchange network (HEN) for a high purity RD process leading to a 34% reduction in the overall energy consumption. Further, a robust control scheme is proposed to mitigate any feed disturbance in the process that may compromise the product purity. Three rigorous case studies are performed to investigate the effect of composition control in the cascade with the temperature control of the product composition. The cascade control scheme effectively countered the disturbances and maintained the fatty acid mono-alkyl ester (FAME) purity. [ABSTRACT FROM AUTHOR]

The effect of core–shell rubber (CSR) toughening on mechanical and thermal properties of poly(lactic acid)/multiwalled carbon nanotubes (PLA/CNT) nanocomposites were investigated. The nanocomposites were prepared by direct melt blending method in a counter‐rotating twin‐screw extruder. The contents of CSR were varied between 5 and 20 wt % while the content of CNT was kept at 5 phr. The extruded samples were injection molded into the desired test specimens for mechanical and thermal properties analysis. The impact strength of PLA/CNT increased with increasing CSR content with concomitant decrease in tensile strength and modulus. Interestingly, the flexural strength increased at low CSR content before decreasing at 15 and 20% content. Differential scanning calorimetry analysis on the second heating cycle shows no crystallinity content for PLA/CNT and all CSR toughened PLA/CNT nanocomposites, while thermogravimetric analysis shows lower thermal degradation of all CSR toughened PLA/CNT as compared to PLA/CNT nanocomposite. This study reveals significant correlation between CSR loading with the mechanical and thermal properties of the nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47756. TEM micrograph of core‐shell rubber toughened PLA/CNT nanocomposites [ABSTRACT FROM AUTHOR]