High Oil Retention Research Articles

Facile Synthesis of a Layered Bismuth-Based MOF With Superhydrophobic-Oleophilic Property and High Oil-Water Separation Performance.

Metal organic frameworks (MOFs) are a class of potential superhydrophobic-oleophilic materials. The organic ligands in superhydrophobic MOFs usually contain long alkyl chains, fluorine groups or aromatic rings with large π conjugation, the preparation of which suffers from high cost, complex operation and so on. In addition, the topological structure of MOFs plays an important role in the hydrophobicity, which may be ignored previously. Here we report a superhydrophobic-oleophilic MOF (BiPPA2) obtained by a facile and fast method, which not only displays a large water contact angle of up to 163° and a small sliding angle of nearly equal to 0°, but also exhibits high sorption capacity for multiple oils and organic solvents, well reusability and high oil retention. In addition, BiPPA2 is stable in a wide pH range (0.5-11.0). Finally, the single crystal structure of BiPPA2 is resolved to reveal the intrinsic reason for the super-hydrophobicity. This work may inspire the further design of pristine superhydrophobic MOFs based on a simple method, which enriches the family of superhydrophobic MOFs and has great significance for practical applications.

Preformulation studies of an emulsion containing commercially available argan oil

Background: Argan oil has gained popularity in recent years due to its potential anti-inflammatory and antioxidant properties. The present pre-formulation study sought to investigate the suitability of using commercially available argan oil as a unique pharmaceutical emulsion formulation for oral consumption. This research aimed to develop an efficient pre-formulation strategy for oil-in-water emulsion containing argan oil and optimize the formulation's optimum stability as a pharmaceutical dosage form. Methods: Various analytical and physical characterization techniques were employed in making an emulsion, such as organoleptic analysis, pH level, viscosity, particle size distribution, gravimetric test, and dye method test. The three formulations (A, B, and C) gave different results for the sizes of oil droplets, appearance, taste, and compatibilities. Results: Among the tested formulations, formulation A, containing 5 ml argan oil, exhibited a cloudy white appearance, hazelnut-like taste and texture, higher oil retention, and improved droplet size dispersion (0.58 μm - 116.21 μm). The results indicated that all three formulations have acidic pH values 4.82-5.84. Conclusion: Formulation A demonstrated notable attributes, making it the optimal choice for the oil-in-water emulsion containing argan oil. Addressing compatibility concerns and assessing sensory attributes, pH levels, and particle size distribution successfully achieved the desired pharmaceutical elegance, laying a promising foundation for developing stable and effective oral emulsions.

Biomimetic structural aerogel derived from green tide enteromorpha-prolifera: Multi-sided unidirectional freeze casting and solar-driven viscous oil spill remediation

The development of environmental remediation materials from renewable biowaste, especially for the cleanup of viscous oil spills in an eco-friendly manner, marks a substantial advancement in functional materials. This study proposes a biomass aerogel (M−MCEP) transformed from Enteromorpha prolifera (EP) in green tides for solar-driven recovery of high-viscosity oil spills. Inspired by the lamella-bridge architecture of Thalia dealbata stems, a biomimetic structure with multi-domain, long-range aligned lamella-bridge interconnections is constructed by a multi-sided unidirectional freeze-casting technique. Multi-scale interface optimization between rigid photothermal fillers and soft lamellar layers achieves multiple reinforcements, providing aerogel with a perfect balance of elasticity and strength. The multidomain low tortuosity channels and photothermal effects enhance M−MCEP’s photothermal conversion (95.2 %) and thermal conductivity (0.3517 W/m·K), reducing oil flow resistance and achieving high oil retention efficiency (>92 %). Under 1 sun irradiation, M−MCEP rapidly heats to 67.3 °C, effectively reducing the viscosity of crude oil in situ, with a crude oil adsorption rate of 1843 mL/m2 within 30 s. Moreover, M−MCEP captures emulsified oil in oil-in-water emulsions through high-speed repeated oscillations, achieving a separation efficiency of 96.42–99.21 %. Renewable resources and unique structural designs provided by nature drive the development of advanced biomimetic aerogels for efficiently remedying catastrophic oil spills.

Rice protein hydrolysates as natural emulsifiers for an effective microencapsulation of orange essential oil by spray drying

This study aimed to identify the influence of rice protein hydrolysates (RPH) (degree of hydrolysis DH of 2, 6, and 10%) and rice protein isolate (RPI) on the formation and stabilization of the volatile oil droplets and to verify how protein hydrolysate affects the distribution of components on the surface and physicochemical properties of the spray-dried microparticles. In general, RPHs could reduce the interfacial tension (3.78–4.04 mN/m) compared to non-hydrolyzed protein (4.74 mN/m). However, no significant difference was observed between RPH samples. A positive correlation was observed between the interfacial tension and the oil droplet size, in which RPH emulsions showed 8.29–8.66 µm while RPI was 9.06 µm. DH influenced the surface composition of the spray-dried RPH emulsions. RPH10 powder showed a greater presence of protein (3.3%) on the particle surface and consequently exhibited high oil retention (50.0%). In contrast, this sample presented high hygroscopicity attributed to the protein surface. This study provides insights into differences between RPH powders, which can potentially impact the powder functionality and protection of the active compound.

Experimental investigation of hydrocarbon generation, retention, and expulsion of saline lacustrine shale: Insights from improved semi-open pyrolysis experiments of Lucaogou Shale, eastern Junggar Basin, China

The organic-rich shale deposited in a saline lacustrine setting contributes massive conventional and unconventional petroleum reserves. However, the hydrocarbon generation, retention, and expulsion of saline lacustrine shale with increasing thermal maturity were rarely reported. Predicting the quality and quantity of generated, retained, and expelled hydrocarbons under various maturity stages for a given shale before drilling persists as a vital issue in exploration. Here, this study conducted two improved semi-open pyrolysis experiments to investigate the characteristics of the hydrocarbon generation, retention, and expulsion of Lucaogou Shale. Solid residues, adsorbed oil, free oil, expelled oil, and hydrocarbon gases were carefully quantified during the pyrolysis experiments. The results reveal that the composition and quantity of generated hydrocarbons are determined by the maturity and degree of openness of the shale system. The Tasmanites of Lucaogou Shale rapidly were converted to abundant oil in the main oil stage, promoting oil retention and expulsion. Meanwhile, the yield of adsorbed and free oil reached its peak at the VRo of 1.01 %. In the late oil window, the previously retained oil was further expelled from the shale as thermal stress increased. High oil retention significantly promoted the generation of extensive wet gas due to secondary cracking within the gas window. However, in a more open system, most of the generated oil was expelled within the oil window. The Lucaogou Shale generates relatively small amounts of hydrocarbon gas through kerogen cracking within the gas window. Hence, the extent of oil transformation into gas is controlled by the residence time and quantity of retained oil in shale. In addition, the maturity range of the oil saturation index greater than 100 mg oil/g TOC in Lucaogou Shale is relatively wide (VRo of 0.9 %-1.5 %), consistent with the renowned Woodford Shale. Expanded geochemical data of natural shale and artificial maturation experiments indicate the distribution of potential hydrocarbon resources. These valuable insights enhance the possibility of searching for commercial shale oil and conventional hydrocarbon resources. Collectively, these findings provide critical new insights into the hydrocarbon generation, retention, and expulsion of saline lacustrine shale, and the results could be a valuable analog for other saline lacustrine petroleum systems worldwide.

Harnessing date fruit pomace: Extraction of high fibre dietary ingredient and its impact on high fibre wheat flour dough

Extracting value from date fruit pomace, commonly dismissed as animal feed by date syrup factories, unveils a substantial composition of both insoluble and soluble fibers, along with valuable phenolic compounds. This nutritional profile positions date fruit fibre as an option for consumers seeking alternative fibre sources. This study investigates the extraction of high fibre date ingredient from date fruit pomace and its integration into bread wheat flour at replacement levels of 5%, 10%, 15%, and 20% (w/w). The research examines the resulting bread dough's properties using farinograph, rheometer, texture analyzer and optical microscopy. Furthermore, it explores the potential of high fibre dietary ingredient as a valuable fibre supplement. Our findings reveal that high fibre dietary ingredient is rich in insoluble fibre and phenolic antioxidants, has moderate moisture and protein content, and low-fat levels. It displays promising high water and oil retention capacity. However, substantial incorporation into bread flour leads to the formation of a hardened, adhesive dough with low stability to mixing. These findings provide insights into the diverse potential applications of high fibre dietary ingredient, highlighting its characteristics and challenges when utilized in baking practices.

Physico-Chemical Characterization of Encapsulated Fennel Essential Oil under the Influence of Spray-Drying Conditions

In this study, fennel essential oil (EO) was spray-dried, varying the wall material type (two-component blends of maltodextrin (MD), β-cyclodextrin (β-CD) and gum arabic (GA)), the wall material ratio (1:1, 1:3 and 3:1) and the drying temperature (120, 160 and 200 °C). A total of 27 powders were analyzed for their moisture content, solubility, hygroscopicity, bulk density and particle size, while powder recovery and oil retention were determined in terms of encapsulation efficiency. The morphology and chemical composition of the powder obtained under optimal conditions were additionally analyzed by scanning electron microscopy and gas chromatography-mass spectrometry. The results showed that all of the powders had generally good properties, exhibiting a low moisture content, high powder recovery and high oil retention. A 1:3 MD:GA mixture and a drying temperature of 200 °C were found to be optimal for the spray-drying of fennel EO, producing a powder with a low moisture content (3.25%) and high solubility (56.10%), while achieving a high powder recovery (72.66%) and oil retention (72.11%). The chemical profiles of the initial and encapsulated fennel EO showed quantitative differences without qualitative changes, with an average 24.2% decrease in the volatiles in the encapsulated EO. Finally, spray-drying proved to be a successful tool for the stabilization of fennel EO, at the same time expanding the possibilities for its further use.

Influence of essential oil: cyclodextrin ratio and stirring rate on physicochemical characteristics of orange essential oil: β-cyclodextrin microparticles

ABSTRACT Some encapsulation process and formulation parameters influence on several physicochemical properties of the encapsulated products. In this study, the influence of the OEO:β-CD ratio and stirring speed on the total oil, surface oil, oil retention, entrapment efficiency, yield, size distribution (d10, d32, and d43), span value, bounding rectangle aspect ratio (BRAR), Feret’s aspect ratio (FAR), circularity, smoothness, and opacity of microparticles were examined. The superior entrapment efficiency (95.18%), highest oil retention (79.13%), and lowest surface oil content (10.02 mg oil/g powder microparticles) were achieved at an OEO:β-CD ratio of 0.15 (w/w) and stirring speed of 700 rpm. Likewise, all microparticles showed irregular and elongated shapes, in which the opacity distribution was more influenced. Finally, the obtained FTIR spectra contained OEO bands hidden inside β-CD peaks, indicating the occurrence of a complexation reaction after encapsulation.

Evaluation of chia gel incorporation as a fat substitute in Nile tilapia fishburger

Chia gel is known for its functional properties such as high water and oil retention capacity, emulsifying activity, and as a stabilizer for foams and emulsions. Thus, the objective of this study was to evaluate the effect of the inclusion of chia gel as a substitute for pork fat in formulations of fishburgers made with Nile tilapia. Five formulations, one control and four with increasing levels of substitution of chia gel (12.50, 25.00, 37.50 and 50.00%) were evaluated. The fishburgers were characterized regarding their physicochemical composition, their technological characteristics, and microbiological viability. With the incorporation of the gel, there was a significant reduction in lipid component and the caloric value of the formulations, in addition to an increase in the percentage of dietary fibre. In addition, no negative effects were observed regarding yield and the main texture parameters studied. However, the formulations with the highest percentage replacement of pork fat by chia gel were darker when compared to the control treatment. Chia gel may be considered as a novel substitute for pork fat; however, it is recommended that techniques be employed to produce lighter gels, thus avoiding possible rejection by the consumer.

A natural armor-protected absorbent from discarded durian peel with rapid and recyclable absorption, high oil retention and self-cleaning ability

How to use simple and effective methods to achieve the recycling of discarded durian shell (DP) is still a huge challenge. Herein, the one-step in situ hydrophobic modification method based on self-generated surface roughness of low surface energy polysiloxane nanofilaments is proposed to prepare natural armor-protecting absorbent from discarded DP while imparting the absorbent versatility. This method gives the absorbent outstanding oil-water selectivity. For the absorption of chloroform, the absorbent can reach the absorption equilibrium in only 10 s, holding rapid absorption kinetics. The absorbent also shows a good recyclability and high oil retention capacity. In addition, the hydrophobicity also allows the absorbent to remove particulate pollutants from the surface, holding exceptional self-cleaning ability. Direct turning the pristine DP into the multifunctional material provides simpler preparation process, which can be used as a new design idea for the practical application of the DP.

Oil Mobility of Low-Mature Lacustrine Shale and Controlling Factors: A Case Study from the Upper Cretaceous Nenjiang Formation, Gulong Sag, in the Songliao Basin

Producing low-mature shale oil resource is becoming economically available as in situ organic matter or heavy oil conversion technologies are introduced to shale oil production. However, we still lack suitable evaluation parameters and criteria for characterizing oil content and mobility in low-mature shales, which are very important for low-mature shale oil economic production. With the aim to better understand the influence factors for low-mature shale oil content and mobility, 16 shale core samples were collected from low-mature Upper Cretaceous Nenjiang Formation (K2n), Gulong Sag, in the Songliao Basin, to investigate their mineral composition and organic geochemical and pore characteristics. The results show the following: (1) Four shale lithofacies were identified, such as mudstone, carbonate lamina shale, bioclastic shale, and mixed lamina shale. (2) Shale oil mobility [represented by the oil saturation index (OSI)] was mainly controlled by large-sized pore distribution. (3) Total organic carbon (TOC) content and lithofacies had great influence on the distribution of oil mobility in the shale. As for mudstone and bioclastic shale, TOC played the most important role in controlling shale oil mobility, whereas for carbonate lamina shale and mixed lamina shale, TOC and mineral variation both have impacts on oil mobility. (4) The average contents of TOC, S1, and OSI in K2n were higher than those in the deeper Qingshankou shale. The oil mobility controlling factors in K2n and K2qn were both TOC and preservation conditions. (5) A new index was proposed to weigh the content of shale oil, in situ OSI, and multiple isothermal pyrolysis parameter S2-2. The in situ OSI shows that K2n has high oil retention capacity, and the in situ oil mobility is 2–3 times the movable oil content.

A facile energy-efficient approach to prepare super oil-sorbent thin films

Oil spills on water surface and shoreline have caused significant water pollution, and one of the ways to deal with them is to use oil sorbents. An effective sorbent provides high oil uptake and retention values, high selectivity, super-fast uptake kinetics, and sufficient mechanical strength to ensure practical application under different conditions. In this regard, synthetic sorbents made up of graphene, carbon nanotubes, and polymers in the form of aerogels, thin films, pads, and non-woven fibers have been widely explored. However, none of them addresses all the attributes of an ideal oil sorbent. Aerogels provide extremely high uptake values, but they are so light that it is difficult for the end user to handle them. On the other hand, thin films and non-woven fibers can quickly absorb oil but suffer from low uptake capacity with low retention values. Similarly, commercial oil sorbent pads have sufficient mechanical strength, but low uptake capacity compared to aerogels. Herein, we present a super oil sorbent with a porous structure using a facile energy-efficient approach. The as-prepared sorbent comprises a porous thin film with micropores and macro-cavities, resulting in super-fast uptake kinetics and a high oil uptake value of 85 g/g. Moreover, tensile test results confirm sorbent’s effectiveness in spill response. Lastly, our unique design does not involve expensive hydrophobic functionalization and thus utilizes lower embodied energy and generates lower carbon footprints.

Hollow polyester/kapok/hollow polyester fiber-based needle punched nonwoven composite materials for rapid and efficient oil sorption.

Nowadays oil pollution poses a serious threat to the environment and people's daily life. As reusable and environmentally friendly materials, fiber-based oil sorption materials can effectively alleviate this phenomenon. However, maintaining a high sorption rate along with improved mechanical properties remains a challenge for oil sorption materials. Herein, we report a novel hollow PET/kapok/hollow PET nonwoven with high porosity and oil retention, outstanding cyclic oil sorption rate and improved mechanical performance using kapok as the oil preserver and hollow PET as the conductor and structure enhancer. Benefiting from the three-layer composite structure fabricated by carding and needle punching reinforcement, the resulting oil sorption materials, with kapok proportion more than or equal to 60%, exhibited high oil sorption rate and oil sorption speed. The materials of 20HP/60K/20HP component content present a high initial oil sorption rate of 28.22 g g-1, a maximum oil sorption rate of 31.17 g g-1 and a sorption rate constant of the Quasi second-order kinetic equation of 0.067 in plant oil. On the other hand, when the proportion of kapok fiber in the material was below 60%, due to the introduction of hollow PET, the mechanical properties were significantly boosted, and its oil retention and reusability were distinguished, with a reuse rate stabilizing at a relatively high level (>93%) in plant oil after undergoing three oil sorption cycles. The successful fabrication of hollow PET/kapok/hollow PET nonwovens could provide a new approach for the design and development of oil sorption materials.

Preparation and Modification of Porous Polyetheretherketone (PEEK) Cage Material Based on Fused Deposition Modeling (FDM).

To address the problems of the difficult processing and internal microstructure disorder of porous bearing cages, Polyetheretherketone (PEEK) porous self-lubricating bearing cage material was prepared based on a fused deposition molding (FDM) process, and the porous samples were heat-treated on this basis, the research was carried out around the synergistic design of the material preparation, microstructure, and tribological properties. The results show that the pore size of the PEEK porous material prepared by the FDM process meets the requirements of the porous bearing cage; the samples with higher porosity also have higher oil content, and all the samples show high oil retention. Under dry friction conditions, the higher the porosity of the porous material, the larger the friction coefficient, and the friction coefficients of each sample after heat treatment show the same pattern; under starved lubrication conditions, the friction coefficient of the porous PEEK material decreased significantly compared to the compact PEEK material, showing a better self-lubrication effect, and the porous samples reached the best self-lubrication effect after heat treatment. The optimal process parameters were 60% mass fraction of NaCl, 40% mass fraction of PEEK, and the applied heat treatment process.

Super-hydrophobic cotton aerogel with ultra-high flux and high oil retention capability for efficient oil/water separation

Natural biodegradable cotton-based materials are one of the promising materials for oil/water separation. However, the high oil retention ability of the oil/water separation materials benefiting oil transportation and storage is often ignored, and the separation flux of these cotton-based materials is usually unsatisfactory, hindering their applications. In this work, a super-hydrophobic cotton aerogel was prepared through a facile and mild dipping-heating process for oil/water separation. The obtained super-hydrophobic cotton aerogel with high porosity (about 94%), and super-hydrophobic surface (water contact angle as high as 152.7° ± 1.1°, and sliding angle as low as 9.2° ± 0.2°) showed excellent structural strength, allowing them to get an ultra-high separation flux (about 37,000 L m−2 h−1) as well as a high oil retention ability. This work provides a facile approach to fabricating cost-effectively and environment-friendly materials for efficient oil/water separation.

Efficacy of hierarchical pore structure in enhancing the tribological and recyclable smart lubrication performance of porous polyimide

Herein, a porous oil-containing material with hierarchical pore structure was successfully prepared through microtexturing large pores on the surface of porous polyimide (PPI) with single-level small pores. Compared to the conventional oil-containing material, the hierarchically porous oil-containing material exhibited high oil-content, and retained excellent mechanical properties and high oil-retention because of the synergistic effects of large pores and small pores. Furthermore, the lubricant stored in the hierarchically porous polyimide could release to the interface under thermal-and-mechano-stimuli, and the released lubricant could be reabsorbed into the hierarchically porous polyimide via the capillary-force offered by the porous channel. Based on the high oil-content and recyclable oil release/reabsorption, the hierarchically porous oil-containing polyimide exhibited excellent lubrication performance (coefficient of friction was 0.057). Furthermore, the composite could perform 1,069 cycles of smart lubrication (1 h per cycle), which significantly extended the service life of the hierarchically porous oil-containing smart lubrication material.

Alginate-oil gelator composite foam for effective oil spill treatment

Oil spills threaten ecosystem and health seriously. Porous foams have been proved as ideal candidates for oil absorbents, however, many with poor oil retention (re-bleeding). Here, we creatively developed a composite foam oil absorbent capable of oil absorption and oil gelation, based on porous alginate foam and hydroxyl aluminum stearate oil gelator. The microstructure of alginate foam can be adjusted by the addition of t-butanol in the solvent, and long alkyl chains of gelator endow foam skeleton with good hydrophobicity, avoiding secondary pollution from traditional hydrophobic chemical modification. Interconnected skeleton decorated by oleophilic gelators contributes to high oil absorption. Oleophilic gelator can self-assemble into 3D network to entrap oils to form gels, giving rise to effective oil retention, realizing the integration of high oil absorption and oil retention. The natural abundant, low-cost composite foam would be promising for tackling oil spills.

Effect of co-electrospinning system on morphology and oil adsorption of helical nanofibers

In this study, inspired by cucumber tendrils, nanofibers with helical morphology are fabricated in co-electrospinning systems with different spinneret configurations. Poly(m-phenylene isophthalamide) (Nomex) and thermoplastic polyurethane are chosen as the two components in co-electrospinning. Using simulation and experimental methods, the electric field distribution and the morphology of nanofibers from the three co-electrospinning systems are analyzed. The helical nanofibers generated from the off-centered spinneret co-electrospinning system possess a helical shape with larger curvature and show higher tensile strain. In addition, the helical nanofibers show an oil adsorption capacity up to 79.3 g g−1 and high oil retention (91%). This study may help control helical fiber morphology and extend the applications of helical materials.

Superoleophilic-Hydrophobic Kapok Oil Sorbents via Energy Efficient Carbonization

ABSTRACT High oil sorption, dynamic oil/water selectivity and oil retention are essential for advanced materials to remediate offshore oil spills. In this context, superoleophilic-hydrophobic kapok bundles, synthesized via a simple, one-step and energy efficient carbonization (300°C), were investigated as effective oil sorbents. It was shown that the surface roughness and intrinsic graphite phase of the kapok bundles were tunable by varying the carbonization temperature, thereby enhancing their oil sorption and retention. Lumen preservation enables the carbonaceous kapok bundles to exhibit tunable oil sorption capacities of 34.0 g/g – 95.5 g/g for various types of oil, unrivaled among other oil spill recovery methods. The origin of oil permeability into lumen is attributed to nanopores observed for the first time on the carbonaceous kapok fibers. The kapok bundles selectively absorbed oil slick under vigorous water vortex and demonstrated distinctly high oil retention of 100% under gravitation force. Multiple oil sorption-desorption and compression cycles (up to 15 times) demonstrate a considerable promise of the carbonaceous kapok bundles for high reusability with low environmental impact.

Supramolecular Oleogel-Impregnated Macroporous Polyimide for High Capacity of Oil Storage and Recyclable Smart Lubrication

Developing smart lubrication materials to achieve recyclable and durable lubrication and excellent wear resistance under various running conditions has great significance in fields ranging from aerospace to advanced engineering machinery but has proven challenging. Herein, a supramolecular oleogel with reversible gel-to-liquid transition was impregnated into macroporous polyimide (MPPI-gel) to obtain a smart lubrication material, which exhibited recyclable smart lubrication with an enhanced oil content and oil retention. The self-assembly of the gelator in polyalphaolefin10 (PAO10) formed three-dimensional networks that encapsulated the PAO10 during the service process, and the MPPI-gel could exhibit a high oil retention (approximately 99%). The gel-to-liquid transition allows the lubricant to be extruded and transferred to the surface of the macroporous matrix (MPPI) under thermal-mechano-stimuli and vice versa. The extruded lubricant can be sucked back into the MPPI pores through the capillary force and recovered to the oleogel when removing the external stimuli. Due to the high oil content, high oil retention, and recyclable lubricant releasing/reabsorbing, MPPI-gel exhibited recyclable smart lubrication (at least 1852 cycles; each cycle lasted for 1 h), a stable coefficient of friction (∼0.06) under alternating conditions (the frequency varied from 1 to 20 Hz, and the load varied from 10 to 46 N), and long-term conditions (at least 10 days). Therefore, MPPI-gel holds the promise of realizing smart lubrication according to the external stimuli with both high oil storage and recyclable lubricant releasing/reabsorbing with the porous matrix.