Castor Oil Research Articles

Anti-diarrheal effects of ethanol leaf extract of Eleusine Indica in Castor Oil induced diarrhea using mice model

Ancient civilizations employed medicinal herbs to treat ailments. Medicinal herbs are essential for treating chronic disorders. Different medicinal plants can treat comparable ailments, depending on the country. In many rural communities in developing countries, particularly in Africa, therapeutic medicines and remedies derived from indigenous plants are almost invariably the only readily available and cost-effective alternatives to traditional diarrhea medicines. The study aims to evaluate the anti-diarrheal activity of the Eleusine indica ethanol extract in mice. The study used fresh Eleusine indica leaves. The extracts were administered at concentrations of 250, 500, and 1000 mg/kg for 28 days. On the 29th, the rats were induced with diarrhea, and blood samples were collected through the retro-orbital plexus before being sacrificed. The serum from the collected blood was used to run hematological and electrolyte tests. The liver and kidney function tests were analyzed using standard methods. The determination of antidiarrheal activity was done using the following models: Castor oil (CO) induced diarrhea, CO induced enteropooling activity, and CO induced gastrointestinal motility. The 80% ethanol extract produced significant (p<0.001) antidiarrheal activity in all three models tested. The hematological, renal, hepatic, and electrolyte parameters of extract-treated mice were not significantly (p > 0.05) different from those of the control group. There was no statistically significant difference (p > 0.05) in the chloride, sodium, potassium, calcium, and bicarbonate levels of the extract-treated groups when compared to the control group. The findings of the studies demonstrated the antidiarrheal activities of Eleusine indica leaves, which could be a therapeutic option against diarrhea.

Assessing Therapeutic Potentials of Catharanthus roseus (L.) G. Don Focusing on Anti-Diabetic, Analgesic and Anti-Diarrheal Activities

Catharanthus roseus, or 'Nayantara' in Bengali, is a perennial flowering herb. This study aimed to evaluate the pharmacological effectiveness of the plant, focusing on its anti-diabetic, peripheral and central analgesic, and antidiarrheal effects. Methanol soluble partition 200 (MSP-200) and 400 (MSP-400) mg/kg body weight were administered for glucose tolerance test (GTT), heat and chemical-induced response tests, sodium thiosulphate induced test, and castor oil induced test, evaluating anti-diabetic, peripheral and central analgesic, and antidiarrheal effects via in-vivo assay in Swiss-Albino mice model. Methanol soluble partition (MSP) at 200 and 400 mg/kg doses significantly reduced the blood glucose levels of mice by 31.00% and 32.97%, respectively (standard 46.24%). In peripheral analgesic activity, MSP-400 (62.82 ± 4.62%) outperformed MSP-200 (50 ± 3.62%) and MSP-200 (p = 0.0001) exhibited statistically significant central analgesic activity. MSP-400 demonstrated potent anti-diarrheal activity (p = 0.0002). The outcomes from this study put forward a cogent argument that C. roseus plant is capable of producing numerous bioactive compounds such as flavonoids, alkaloids, terpenoids, tannins, etc. which requires systematic phytochemical and pharmacological investigations. Bangladesh Pharmaceutical Journal 27(2): 215-222, 2024 (July)

A sulfonated hyperbranched bio-based waterborne polyurethane sizing coating for the enhancement of mechanical properties and surface wettability of carbon fibres

Wet-weaving and cluster braiding in industrial production processes generate irreversible defects and grooves in carbon fibre (CF) filaments, which reduce the service life and mechanical properties of the fibres. Additionally, the fibre surface covered with numerous inactive carbon-containing groups and presents chemical inertness, which limits the prospects of CF applications. Hence, the hyperbranched bio-based waterborne polyurethanes (SWPU) possessing the synergism of sulfamate and carboxylate complex hydrophilic units were adopted as sizing coatings to improve the flexural and tensile strengths of CF, as well as fibre surface roughness and wettability. The SWPU is designed on dihydroxymethylbutyric acid and sulfamates (A95) as per- and post-chain extenders, respectively, trimethylolpropane (TMP) as an intramolecular cross-linker, and plant-extracts castor oil (CO) replacing petroleum-based petrochemicals as the soft-segments. The construction of CO-TMP hyperbranched cross-linking networks and the strengthened hydrogen-bonding effects of the polar sulfamates positively affect the intermolecular interactions and configuration stability of SWPU sizing coatings. SWPU revealed favourable thermo-mechanical properties achieving a T5% decomposition temperature and toughness of 297.83 °C and 35.24 MJ/m3. The coating effects of the bio-based sizing agents not only repaired defects and improved surface roughness on CF, but the polar groups in SWPU comprising SO3Na, carbamate and polyurea promoted the chemotactic activity and wettability of the fibres. The surface energy and tensile strength of the SWPU sized CF reached 43.75 mN/m and 5.68 GPa, respectively, which were 45.4 % and 30.7 % higher compared to original CF. The research contributes to the development and industrial production of high-performance, eco-friendly bio-based sizing coatings.

Valorization of Kraft Lignins from Different Poplar Genotypes as Vegetable Oil Structuring Agents via Electrospinning for Biolubricant Applications.

This work explores the use of Kraft lignins sourced from different poplar genotypes (Populus alba L. "PO-10-10-20" and Populus × canadensis "Ballotino") isolated by selective acid precipitation (at pHs 5 and 2.5) to produce electrospun nanostructures that can be further employed for structuring vegetable oils. This approach offers a new avenue for converting these waste materials into high-value-added ingredients of eco-friendly structured lubricants. Electrospinning of poplar Kraft lignin (PKL)/cellulose acetate (CA) solutions yielded homogeneous beaded nanofiber mats that were able to generate stable dispersions when they were blended with different vegetable oils (castor, soybean, and high-oleic sunflower oils). Electrospun PKL/CA nanofiber mats with larger average fiber diameters were achieved using the lignins isolated at pH 5. Dispersions of PKL/CA nanofibers in vegetable oils presented gel-like viscoelastic characteristics and shear-thinning flow behavior, which slightly differ depending on the nanofiber morphological properties and can be tuned by selecting the poplar lignin genotype and precipitation pH. The rheological properties and tribological performance of PKL/CA nanofibers suitably dispersed in vegetable oils were found to be comparable to those obtained for conventional lubricating greases. Additionally, lignin nanofibers confer suitable oxidative stability to the ultimate formulations to different extents depending on the vegetable oil used.

Enhancing the tribological performance of composite electrostatic spray lubrication using blended plant oils

As a sustainable machining lubrication technique, composite electrostatic spray lubrication (CESL) adopts a high-voltage electric field to atomize oils (external fluid) and water (internal fluid) into oils-on-water (OoW). Although castor oil shows excellent lubrication properties, its high viscosity and low electrical conductivity lower the atomization performance and impede the attainment of ideal tribological performance in CESL applications. Blending castor oil with other plant oils is anticipated to effectively resolve this matter through the improvement in chargeability and fluidity. Nevertheless, no research work on the use of blended plant oils to enhance the CESL performance has been conducted. This study employed sliding friction tests between carbide slices and steel discs to explore the tribological performance of CESL under various blended types, blended ratios, external/internal flow rates, and voltages. The physical properties and fatty acid compositions of blended plant oils, as well as the charging and electrowetting capabilities of OoW, were examined to study their impacts on the tribological performances of CESL. The research findings demonstrated that the application of blended plant oils improved the tribological performance of castor oil-based CESL. The optimal blended type, blended ratio, external/internal flow rate, and voltage were respectively castor oil blended with soybean oil, 1:2, 8/4 ml/h, and −7.5 kV. Compared to the CESL employing castor oil and commercial plant oil, the blended plant oil-based CESL with optimized parameters led to reductions of 89.99–96.40 % in the coefficient of friction, 93.33–97.33 % in the carbide wear loss, and 70.00–73.80 % in the depth of disc wear marks, respectively. The research outcomes are helpful to understand the tribological behavior of blended plant oil-based CESL, thus providing a reference for its practical application.

Synergistic enhancement of rheological and anti-aging properties of asphalt modified with bio-oil and layered silicate

Applying bio-oil to asphalt pavement effectively reduces the dependence on traditional petroleum asphalt in pavement industry. However, the utilization of bio-oil can encounter rutting and aging issue of modified asphalt. To solve the aforementioned issue, two kinds of organic layered silicates with typical structures were adopted to enhance the high-temperature and anti-aging performance of the bio-modified asphalt. The modification mechanism and the synergistic effect of bio-oil and organic layered silicate on asphalt were explored through rheological characterization, infrared spectroscopy tests, gel chromatography tests, etc. Results showed that the incorporation of layered silicate in bio-modified asphalt can improve asphalt-filler interaction and hence the high-temperature and fatigue performance of asphalt. When the content of layered silicate is 5 %, the negative effect of Castor oil on the high-temperature performance of asphalt can be eliminated. Still, for Turpentine wood oil and Straw oil, the content of layered silicate is 7 %, which shows the same effect. The waste bio-oils can balance the low-temperature performance of asphalt modified with layered silicates. Furthermore, the addition of layered silicates was effective to reduce oxidation reaction and improve the anti-aging performance of bio-oil modified asphalt. When the ratio of layered silicate to bio-oil is 1 1, the composite-modified asphalt maintains the best anti-aging performance. Specifically, Castor oil, Straw oil, and OMMT are more suitable, and Turpentine wood oil and OREC are more appropriate. According to the quantification of the functional group aging index, the SI and CI of the optimal ratio of different types of bio-oil asphalt are Castor oil: 61.64 % and 59.41 %, Turpentine wood oil: 50.02 % and 53.57 %, Straw oil: 50.01 % and 55.05 %. Composite modified asphalt can be applied to complex service conditions.

Trends in Area, Production and Productivity of Castor in Telangana

Aims: To analyse the trends in area, production and productivity of castor in Telangana and major erstwhile districts of Telangana. The main purpose of the study is to understand the growth rate of castor in a region of Telangana, as India is the largest exporter of castor oil, which has multiple industrial applications. Methodology: The secondary data of the area, production and productivity of castor from 2001-02 to 2022-23 were collected from the Directorate of Economics and Statistics. The Compound Annual Growth Rate (CAGR) was used to analyse the time-series data of castor. CAGR was calculated for 3 periods -Period I (2001-02 to 2011-12), Period II (2012-13 to 2022-23), Overall Period (2001-23). Results: The results showed a decreasing trend in both castor area and production. But castor productivity observed a positive growth rate in Telangana and the major erstwhile castor-growing districts like Mahbubnagar and Medak. However, few districts like Rangareddy, Nalgonda, and Warangal showed negative trends in productivity during Period I. The study highlighted a decline in the castor area due to the incidence of diseases like Botrytis, shifting to other crops such as cotton and climate variability. Conclusion: The study indicated that the decline in the castor area is a major concern and this study will be useful in agricultural policy making to take appropriate actions to reverse the declining trends of castor cultivation in Telangana.

Dual-Target Additively Manufactured Electrochemical Sensor for the Multiplexed Detection of Protein A29 and DNA of Human Monkeypox Virus.

Herein, we present the first 3D-printed electrochemical portable biodevice for the detection of monkeypox virus (MKPV). The electrochemical device consists of two biosensors: an immunosensor and a genosensor specifically designed for the detection of the protein A29 and a target DNA of MKPV, respectively. The electrodes were manufactured using lab-made ultraflexible conductive filaments composed of carbon black, recycled PLA from coffee pods, and castor oil as a plasticizer. The sensors created through 3D printing technology exhibited good reproducibility and repeatability of analytical responses. Furthermore, both the immunosensor and genosensor demonstrated excellent MKPV detection capabilities, with a linear range from 0.01 to 1.0 μmol L-1 for the antigen and 0.1 to 20.0 μmol L-1 for the DNA target. The biosensors achieved limits of detection of 2.7 and 29 nmol L-1 for the immunosensor and genosensor, respectively. Interference tests conducted with the biosensors demonstrated their selectivity for MKPV. Moreover, analyses of fortified human serum samples showed recoveries close to 100%, confirming the absence of significant matrix effects for MKPV analysis. Therefore, the 3D-printed multiplex device represents a viable and highly promising alternative for on-site, portable, and rapid point-of-care MKPV monitoring.

Green polyurethane foams: Replacing petrochemical polyol with castor oil through factorial design

Green polyurethane foams: Replacing petrochemical polyol with castor oil through factorial design

A sustainable bioprocess technology for producing food-flavour (+)-γ-decalactone from castor oil-derived ricinoleic acid using enzymatic activity of Candida parapsilosis: Scale-up optimization and purification using novel composite

Ricinoleic acid (RA) from castor oil was employed in biotransformation of peach-flavoured γ-decalactone (GDL), using a Candida parapsilosis strain (MTCC13027) which was isolated from waste of pineapple crown base. Using four variables—pH, cell density, amount of RA, and temperature—the biotransformation parameters were optimized using RSM and BBD. Under optimized conditions (pH 6, 10 % of microbial cells, 10 g/L RA at 28°C), the conversion was maximum and resulted to 80 % (+)-GDL (4.4 g/L/120 h) yield in shake flask (500 mL). Furthermore, optimization was achieved by adjusting the aeration and agitation parameters in a 3 L bioreactor, which were then replicated in a 10 L bioreactor to accurately determine the amount of (+)-GDL. In bioreactor condition, 4.7 g/L (>85 %) of (+)-GDL is produced with 20 % and 40 % dissolved oxygen (1.0 vvm) at 150 rpm in 72 h and 66 h, respectively. Further, a new Al-Mg-Ca-Si composite column-chromatography method is developed to purify enantiospecific (+)-GDL (99.9 %). This (+)-GDL is 100 % nature-identical as validated through 14C-radio-carbon dating. Thorough chemical investigation of enantiospecific (+)-GDL is authenticated for its use as flavour. This bioflavour has been developed through a cost-effective biotechnological process in response to the demand from the food industry on commercial scale.

Methane adsorption effect of cyclodextrin-based metal-organic frameworks and ultra-fine water mist composite system in closed container

Natural gas, predominantly composed of methane, is a widely used energy source. Methane is prone to leakage during storage and usage, posing environmental risks. Currently, effective strategies to capture methane leaked in urban environments are lacking. This study investigates the synthesis of a non-toxic Cyclodextrin-based Metal-Organic Framework (CD-MOF) and its adsorption capacity for leaked methane in an ultrafine water mist composite solution system. CD-MOFs, utilizing β-cyclodextrin as the organic ligand and alkali metal potassium as the metal ion, were synthesized via solvothermal and methanol vapor diffusion method. The morphology, functional groups, and thermal properties of CD-MOFs were characterized by multiple techniques. The BET specific surface area, pore structure, and high-pressure methane adsorption capacity of the samples were investigated. Furthermore, CD-MOF, surfactant, and castor oil were combined to create a composite solution absorbent. The methane absorption efficacy of this ultra-fine water mist of absorbent was tested using a closed-container methane spray adsorption apparatus, and the compound solution ratio was optimized. The results indicate that CD-MOFs retain the parent cyclodextrin structure, and the methane adsorption capacity under high-pressure (35 bar) of CD-MOF synthesized by the sodium dodecyl sulfate-assisted solvothermal method reached 216.13 cm3/g. The composite solution with an appropriate proportion of surfactant, castor oil, and CD-MOF reached a methane absorption capacity of 5.7 % vol in enclosed spaces. The successful synthesis of CD-MOFs and the application of composite solutions with ultra-fine water mist offer innovative approaches and theoretical guidance for the emergency absorption and non-toxic disposal of leaked methane.

Screening of Castor Germplasm and Efficacy Studies of Bioagents and Fungicides Against Botryotinia ricini (Godfrey) Whetzel

Castor is an important non-edible oilseed crop having exceptional oil characteristics for the chemical industry. The crop hosts several diseases, among them gray mold is the most destructive one hindering its productivity. This article presents a study assessing the resistance of different germplasm lines screened against Botrytis ricini under artificial conditions. It also examines the effect of various fungicides on B. ricini isolates, which were obtained from infected Ricinus communis (castor oil plant) using standard tissue isolation techniques. The fungus was isolated from infected Castor raceme by standard tissue isolation technique and its pathogenicity was established by proving Koch’s postulates. Out of 47 germplasm lines screened, TSIL-19 showed resistance response to gray mold under both detached spike and capsule method. Under in vitro assessment, Trichoderma viride (86.11 %) and Pseudomonas fluorescens (71.48 %) bio agents exhibited maximum mycelial growth inhibition of the pathogen. Among the seven combination fungicides evaluated, Fenamidone 10% + Mancozeb 50% WG recorded highest mycelial growth inhibition (100%) of B. ricini.

Preparation and properties of biomass castor oil polyurethane films

In order to investigate the optimal conditions for the formation of castor oil-based polyurethane (CO-PU) films and their comprehensive performance, a series of experiments were carried out utilising biomass castor oil (CO) as the main reactant, 4,4-diphenylmethane diisocyanate (MDI) as the other main reactant, benzoyl peroxide (BPO) as the radical initiator, and dibutyltin dilaurate (DBTDL) as the catalyst. The CO-PUs with different R-values (the number ratio of –NCO/–OH substances) were prepared by pre-polymerisation under single-variable control. The effects of different R-values, DBTDL contents and curing temperatures on the mechanical properties and film-forming state of the CO-PUs were then investigated. Finally, the liquid-resistant medium properties and thermo-gravimetric analyses of CO-PU films were investigated. The experimental results demonstrate that when the R value is 2.5, the DBTDL content is 0.1 ‰, and the curing temperature of the film-forming process is 80 °C, the tensile strength and elongation at break of the CO-PU film are 36.4 MPa and 49.05 % respectively, and the hardness of the pencil at this time is 6H. The water absorption rate is 0.01 %, and the contact angle of water is up to 83.5°. CO-PU displays a commendable resistance to sulfuric acid, sodium hydroxide, and ethyl acetate. Additionally, CO-PU exhibits a high thermal decomposition temperature. The comprehensive performance of CO-PU can be enhanced by modifying the film-forming conditions of CO-PU, which paves the way for further expansion of the applications of CO-PU in the future.

Organo-Mediated Ring-Opening Polymerization of Ethylene Brassylate from Cellulose Nanofibrils in Reactive Extrusion.

Ethylene brassylate is a renewable macrolactone from castor oil that can be polymerized via ring-opening polymerization (ROP) to obtain a fully biosourced biodegradable polyester. ROP mediated by organometallic catalysts leads to high molar mass poly(ethylene brassylate) (PEB). However, the use of metal-free organocatalysis has several advantages, such as the reduction of toxic and expensive metals. In this work, a novel cellulose nanofibril (CNF)/PEB nanocomposite fabrication process by organocatalysis and reactive extrusion (REx) is disclosed. Here, ROP was carried out via solvent-free REx in the presence of CNFs using organic 1,5,7-triazabicyclo[4.4.0]dec-5-ene as a catalyst. Neat or lactate-esterified CNFs (LACNF) were used as initiators to investigate the effect of surface topochemistry on the in situ polymerization and the properties of the nanocomposites. A molar mass of 9 kDa was achieved in the presence of both unmodified and LACNFs with high monomer conversion (>98%) after 30 min reaction in a microcompounder at 130 °C. Tensile analysis showed that both nanofibril types reinforce the matrix and increase its elasticity due to the efficient dispersion obtained through the grafting from polymerization achieved during the REx. Mechanical recycling of the neat polymer and the nanocomposites was proven as a circular solution for the materials' end-of-life and showed that lactate moieties induced some degradation.

A Comparative Study to assess the Treatment Cost of Ayurvedic Medicine (Ginger and Castor Oil) and Modern Medicine (DMARDs) in Amavata (Rheumatoid Arthritis)

Ama and Vata are the initial elements in the pathophysiology of Tridosha, whereas Amavata is a result of their vitiation. The expense of treatment is a major factor in the economic burden of RA for both the patient and the health and social care systems. Objective: a. To assess the socio-demographic conditions of the patients of Amavata. b. To compare the cost of a one-month treatment of ginger and castor oil with DMARD in the management of Amavata. Methodology: Total 72 patients of RA Fulfilling the inclusion criteria and having symptoms of RA were enrolled for this Interventional study. Patients were treated in two different groups- Group A- 36 clinically diagnosed and registered patients of Amavata were treated by DMARD Group B- 36 clinically diagnosed and registered patients of Amavata were treated with ginger and castor oil. After the completion of the study, total 62 patients came after one month of treatment, so we included 62 patients in this study. 32 patients in group A and 30 patients in group B Results: The average direct cost of treatment of RA patients in 2024 was estimated as Rs. 2669.17 ($31.96)/month in group A (DMARD Group) and Rs. 1386.69 ($16.62) in group B (Ginger and Castor oil). Major part of total direct costs was covered by medicines (Rs. 1583) in group A and Laboratory cost (Rs. 600) in group B. The ratio of one-month cost of DMARD and Ayurvedic medicine (ginger and castor oil) was 12:1. Discussion: The cost of Ayurvedic medicine was very low in comparison to DMARD. Ayurvedic Medicine ginger and castor oil were easily available, safe, effective and cheap.

Programming degradation and closed-loop recycling of ultra-stable bio-based thermosetting polyurethane relied on double-locked covalent adaptable networks

Castor oil (CO) derived thermoset polyurethanes are usually limited by their poor mechanical properties and the difficulty in removing or recycling because of the aliphatic or alicyclic backbone and their permanent cross-linking structures. Although covalent adaptable networks (CANs) based on dynamic bonds have been proposed, it is still highly desired to fabricate polymer CANs with high performance, stimulus resistance, stepwise degradation and closed-loop recycling from renewable CO for sustainable development. In this study, CO-based poly(urethane urea) (PU) thermosets relied on double-locked covalent adaptable networks (DLCANs) were proposed to achieve programmable degradation and closed-loop recycling. From a CO-derived isocyanate monomers and two dynamic curing agents of aminophenyl disulfide (AFDS) and aminophenyl diimine (AFDI), bio-based thermosets of PU DLCANs were prepared. The bio-based PU DLCANs were ultra-stable and still kept cross-linked upon disadvantageous chemical stimuli instead of dissociating like the conventional CANs. Moreover, the bio-based PU DLCANs became degradable only by applying programmed stimuli, when the two types of dynamic cross-links in parallel connection were both broken step by step. Meanwhile, the broken cross-links could be reformed when dynamic bonds regenerated upon heating, leading to the closed-loop recycling of the bio-based PU DLCANs. Besides, being applied as coatings, the bio-based PU DLCANs exhibited UV shielding, self-healing properties and long-term stability as well as programming removable properties. The bio-based thermosets relied on DLCANs have the potential to guarantee the reliability of polymeric CANs and maintain the closed-loop recycling by applying programmable stimuli, which is quite meaningful and practical for life-time environmental-friendly coatings.

A Comparative Evaluation of the Dissolving Abilities of Eucalyptus, Orange, and Castor Oils in Endodontic Retreatment Using Conventional and Rotary Techniques.

Endodontic retreatment is essential for periapical healing, involving the removal of inadequate fillings, thorough cleaning, and new filling application to prevent leakage. This study compares the dissolving abilities of Eucalyptus, Orange, and Castor oils in the re-treatment of resin-based endodontic fillings using conventional and rotary techniques. Thirty single-rooted human teeth were prepared and filled with gutta-percha and AH Plus sealer. They were divided into three groups (n=10) based on the solvent used (Eucalyptus, Orange, or Castor oil) and further subdivided based on the techniques used (conventional and rotary). Standardised re-treatment procedures were performed, and the amount of residual material was measured. A significant difference (p<0.001) was found among the groups, indicating that both the type of solvent and the technique significantly affected the amount of residual material. The rotary technique generally left less residual material compared to the conventional technique for all solvents. Eucalyptus oil with the rotary technique showed the least residual material (mean = 5.8), while Castor oil with the conventional technique showed the most (mean = 10.2). Eucalyptus oil, especially when used with rotary techniques, is highly effective in removing resin-based endodontic fillings, providing a viable and safer alternative to traditional solvents. The study underscores the importance of selecting appropriate solvents and techniques for successful endodontic re-treatment.

Deciphering the application efficacy of titanium dioxide mediated calcareous nanocatalyst towards biodiesel production

The current investigation delved into the mechanistic insight, and cost-competent application of CaO-derived nanocataysts doped with TiO2 for enhanced biodiesel synthesis from castor oil. Calcium oxide-laden nanocatalysts were prepared via co-precipitation methodology with varying precursor and calcination temperatures concentrations. The engineered catalysts underwent characterization using XRD, SEM, particle size analysis, FTIR, EDX, UV-spectroscopy, and zeta potential measurements. Response surface methodology was implemented to create an experimental matrix for the transesterification. With methanol: oil ratio of 12:1, 5% catalyst weight, 2.25 h reaction interval, and a temperature of 60 °C, the utmost biodiesel yield achieved was 94.27%. Furthermore, the ester-enriched biodiesel was confirmed through GC-MS, 1H NMR, 13C NMR and FTIR analyses. Kinetic and thermodynamic studies revealed the endothermic and irreversible nature of the transesterification reaction. The fuel characteristics of the synthesized castor oil biodiesel are within acceptable ranges. The co-precipitation-derived nano TiO2@CaO catalyst validated impressive catalytic efficacy and stability, making it a proficient heterogeneous catalyst for augmented biodiesel manufacturing from castor oil. The projected expenses for 1 kg TiO2@CaO catalyst and 1 L COBD, obtained from cost assessments, were $ 6.37 and $ 0.578, respectively, showcasing their strong economic feasibility. Lastly, the study also offered future outlooks based on recognized gaps in the reported studies across a contemporary bibliometric investigation.

Exploring Electrohydrodynamic Flows Inside Leaky Dielectric Drops: A Laser Velocimetry Approach

A novel experimental methodology based on laser velocimetry for the investigation of electrohydrodynamic (EHD) flows inside a neutrally buoyant leaky dielectric drop of 2.25 mm of radius is proposed. Utilizing fluorescent particles, 2D and 3D Lagrangian Particle Tracking (LPT) measurements of the EHD flows inside an initially spherical drop under a constant electric field are reported. Two leaky dielectric fluids, namely Silicone and Castor oils, were used as either the drop or the medium phases, depending on the case investigated, thus covering oblate and prolate drops both with small and larger deformations. 2D measurements of the trajectories and velocities of the tracer particles in a Lagrangian referential enabled a direct comparison with the leaky dielectric model (LDM), a well-stablished theory covering drops with smaller deformations, showing a good agreement with our measurements. The symmetry inside a drop with increased deformation is investigated from an analysis of the mean 3D velocity field, whose measurements converge to the two-dimensional analysis at the plane of symmetry of the drop, suggesting symmetrical flow structures inside the drop.

Study of the Adsorption of Anionic Surfactants on Carbonate Rocks: Characterizations, Experimental Design, and Parameter Implementation

Controlling or reducing the adsorption of surfactants on reservoir rock surfaces has been a challenging task in enhanced oil recovery (EOR) methods, as it directly affects the cost-effectiveness of the projects. The adsorption of surfactants on rock surfaces can modify their hydrophobicity, surface charge, and other important parameters that govern EOR processes, such as reducing the interfacial tension between water and oil and increasing permeability. Therefore, understanding the adsorption mechanism on rocks is essential for developing alternatives that improve the effectiveness of these processes. In this work, the adsorption of surfactants on carbonate materials was evaluated considering variations in temperature, contact time, and surfactant concentration. The surfactants used were derived from vegetable oils, aiming for a sustainable approach: saponified coconut oil (SCO), saponified babassu coconut oil (SBCO), and saponified castor oil (SMO). The finite bath method was used, resulting in adsorption efficiencies of 85.74%, 82.52%, and 45.30% for SCO, SBCO, and SMO, respectively. The Sips isotherm and the pseudo-second-order model were found to be suitable for characterizing these systems. The simulation of SCO adsorption isotherms on limestone by the Langmuir model was more accurate than that using the Freundlich model. The limestone showed a negative surface charge of approximately −35.0 mV at pH 6.5; this negative charge varied over a wide pH range. These zeta potential data for the samples confirmed that hydrophobic interactions played an important role in the adsorption of the surfactants. Thermodynamic evaluation indicated spontaneous and endothermic adsorption of SCO on limestone. The systems were also characterized by FTIR, TG/DTG, XRD, XRF, SEM, and zeta potential.