Improved Surface Wettability Research Articles

Atmospheric pressure cold plasma jet–assisted micro-milling TC4 titanium alloy

Micro-milling is a low-cost, efficient, and high-precision machining method for manufacturing tiny parts, and has significant application value in various fields. In order to meet the high-accuracy requirements, several composite micro-milling methods have been proposed. However, these methods cannot change surface characteristics of materials, and poor permeability of cooling medium on the tool-workpiece interface remains unsolved. Atmospheric pressure plasma jet can efficiently improve surface wettability without obviously changing surface microstructures and may have promising application potential in machining of difficult-to-cut materials. Here, we propose to induce atmospheric pressure plasma jet to the micro-milling area to improve machinability and surface quality of TC4 titanium alloy. The influences of plasma jet on material wettability and mechanical property are firstly investigated by conducting plasma modification and tensile experiments. Then, micro-milling experiments of TC4 titanium alloy are performed under different atmospheres (dry, nitrogen jet, plasma jet, minimum quantity lubrication, and plasma jet + minimum quantity lubrication). The experimental results indicate that plasma jet can promote material fracture of TC4 titanium alloy, as well as reduce cutting force and cutting temperature, thereby obtaining better surface quality.

Construction of Nitrogen-Doped Carbon Nanosheets for Efficient and Stable Oxygen Reduction Electrocatalysis

Two-dimensional nitrogen-doped carbon nanosheets (GCNS) have been fabricated through polymerization and carbonization using resorcinol, formaldehyde, aniline and graphene oxide as reactants. Herein, aniline serves as a nitrogen source for doping and graphene oxide is employed as the structure directing agent for nanosheet generation to engineer the structure. The resultant GCNS display a high surface area of 351 m2 g−1 and N doping content of 1.06 wt.%. Moreover, the obtained electrocatalysts demonstrate superior electrocatalytic oxygen reduction characteristics with an onset potential of 0.920 V versus reversible hydrogen electrode, diffusion-limiting current density (− 4.24 mA cm−2) and improved stability in an alkaline medium. The optimized oxygen reduction performance can be attributed to the rapid mass transfer and abundant active sites owing to the synergistic coupling effects arising from heteroatom dopants and structure modulation. On one hand, heteroatom doping provides enhance electronic conductivity with abundant defects and effective charge diffusion with improved surface wettability, which favors the electrocatalytic performances. On the other hand, the unique two-dimensional structure of the resultant GCNS provides good electrolyte accessibility and short ion/electron diffusion distances. This work demonstrates an effective construction of targeted heteroatom doping carbon nanosheets with surface functionalities and structure modification as carbon-based catalysts with advanced electrocatalytic performances.

Modifying surface properties of polysulfone membrane with plasma from closed and opened plasma generators

Plasma jet has been widely used in the process of surface modification. However, the operation process often operates in an opened plasma jet system. This research investigated surface modification of flat-sheet polysulfone membrane by using three different types of atmospheric pressure cold plasma jet system that comprised of plasma jet in an opened system, in a closed system and in a closed with pump out plasma gas system. This research aims to improve surface wettability of membrane surfaces. The samples were irradiated with argon plasma in such three systems. The properties of the treated membranes were verified by measuring Water Contact Angle (WCA), Surface Energy (SE) and surface roughness. The results show that plasma jet in the closed with pump out plasma gas system provided the best results due to its lowest water contact angle, the highest surface energy and the highest surface roughness.

Fluorination-enabled Reconstruction of NiFe Electrocatalysts for Efficient Water Oxidation.

Developing low-cost and efficient electrocatalysts to accelerate oxygen evolution reaction (OER) kinetics is vital for water and carbon-dioxide electrolyzers. The fastest-known water oxidation catalyst, Ni(Fe)OxHy, usually produced through an electrochemical reconstruction of precatalysts under alkaline condition, has received substantial attention. However, the reconstruction in the reported catalysts usually leads to a limited active layer and poorly controlled Fe-activated sites. Here, we demonstrate a new electrochemistry-driven F-enabled surface-reconstruction strategy for converting the ultrathin NiFeOxFy nanosheets into an Fe-enriched Ni(Fe)OxHy phase. The activated electrocatalyst shows a low OER overpotential of 218 ± 5 mV at 10 mA cm-2 and a low Tafel slope of 31 ± 4 mV dec-1, which is among the best for NiFe-based OER electrocatalysts. Such superior performance is caused by the effective formation of the Fe-enriched Ni(Fe)OxHy active-phase that is identified by operando Raman spectroscopy and the substantially improved surface wettability and gas-bubble-releasing behavior.

Coating of a Sand-Blasted and Acid-Etched Implant Surface with a pH-Buffering Agent after Vacuum-UV Photofunctionalization

Ultraviolet (UV) photofunctionalization can reset the biological aging of titanium after the preparation and storage of dental implants by transforming hydrophobic titanium surfaces into superhydrophilic surfaces. Blood clot formation around the implant can initialize and promote the healing process at the bone–implant interface. The aim of this study is to evaluate and compare the capabilities of surface wettability and blood clotting of implants with a conventional sand-blasted and acid-etched surface (SA), a sand-blasted and acid-etched surface with vacuum-UV treatment (SA + VUV), and a sand-blasted and acid-etched surface coated with a pH-buffering agent after vacuum-UV treatment (SA + VUV + BS). Static and dynamic tests for surface wettability and blood clotting were performed in vitro for SA + VUV and SA + VUV + BS (n = 5), while hemostasis resulting from blood clotting was evaluated in vivo for SA, SA +VUV, and SA + VUV + BS (n = 4). A Kruskal–Wallis test showed statistically significant differences (p < 0.05) in all tests, with the exception of in vitro test of static blood clotting. VUV treatment is therefore effective at making an SA surface superhydrophilic as an alternative to routine UV-C radiation. The addition of a pH-buffering agent to SA + VUV also improved surface wettability and blood clotting, which are crucial for successful osseointegration.

Effect of ACQ treatment on surface quality and bonding performance of four Malaysian hardwoods and cross laminated timber (CLT)

The objective of this study is to determine the effects of alkaline copper quaternary (ACQ) treatment on the surface quality and bonding performance of four Malaysian hardwood species, namely batai, sesenduk, rubberwood and kedondong. The samples were impregnated with 2% ACQ preservatives and bonded with phenol-resorcinol–formaldehyde resin for cross laminated timber (CLT) fabrication. The changes in density and the retention of both ACQ and copper after the treatment were recorded. Surface roughness and wettability of both treated and untreated samples were measured. Block shear and delamination tests were performed to evaluate the bond-line strength of CLT. The study revealed that the average surface roughness (Ra) of each species increased significantly. Wettability of batai, sesenduk, rubberwood and kedondong was significantly higher than that of the untreated samples suggesting an improvement in surface wettability. For single-species CLT, treated rubberwood has the highest shear strength followed by kedondong, sesenduk and batai with values of 9.53 N/mm2, 6.00 N/mm2, 5.68 N/mm2 and 4.19 N/mm2, respectively. While for mixed-species CLT, the combination of ACQ-treated rubberwood-sesenduk-rubberwood has the highest block shear strength with a value of 8.05 N/mm2. No delamination was observed from all samples. ACQ treatment was found to not affect the block shear strength significantly. Therefore, ACQ preservatives can be used to produce CLT with good bonding performance.

Surface Characterization and Tribological Performance Analysis of Electric Discharge Machined Duplex Stainless Steel.

The present article focused on the surface characterization of electric discharge machined duplex stainless steel (DSS-2205) alloy with three variants of electrode material (Graphite, Copper-Tungsten and Tungsten electrodes). Experimentation was executed as per Taguchi L18 orthogonal array to inspect the influence of electric discharge machining (EDM) parameters on the material removal rate and surface roughness. The results revealed that the discharge current (contribution: 45.10%), dielectric medium (contribution: 18.24%) majorly affects the material removal rate, whereas electrode material (contribution: 38.72%), pulse-on-time (contribution: 26.11%) were the significant parameters affecting the surface roughness. The machined surface at high spark energy in EDM oil portrayed porosity, oxides formation, and intermetallic compounds. Moreover, a pin-on-disc wear analysis was executed and the machined surface exhibits 70% superior wear resistance compared to the un-machined sample. The surface thus produced also exhibited improved surface wettability responses. The outcomes depict that EDMed DSS alloy can be considered in the different biomedical and industrial applications.

Mechanical and chemical properties of PVD and cold spray Cr-coatings on Zircaloy-4

Accident-tolerant fuel (ATF) cladding materials aim to improve fuel reliability and safety during accident scenarios in water-cooled reactors. These ATF cladding should also perform comparable or better than the current zirconium alloy cladding under reactor normal operating conditions. Surface-modified Zircaloy-4 was produced by depositing a protective coating of chromium by two different coating techniques, Physical Vapor Deposition (PVD) and Cold Spray (CS). The coating thickness, structure, composition, and mechanical properties of the coated Zircaloy were assessed with advanced materials characterization techniques. Results showed a strengthening effect of the Cr-coating, along with ∼83% higher hardness compared to that of the Zircaloy-4 substrate. Surface topography and surface chemistry of the Cr-coated Zircaloy-4 were assessed with contact profilometry, atomic force microscopy, contact angle goniometry, and X-ray photoelectron spectroscopy. Deposited Cr-coating significantly improved surface wettability compared to the substrate Zircaloy-4. The formation of surface oxides on the coatings by prolonged exposure to ambient air showed a further increase in the hydrophobic behavior. Surface parameters and surface chemistry after flow boiling critical heat flux tests, conducted at atmospheric pressure, evidenced a slight increase in surface roughness with notable changes in wettability associated with the formation of surface oxides.

Effects of varying electrodeposition voltages on surface morphology and corrosion behavior of multi-walled carbon nanotube coated on porous Ti-30 at.%-Ta shape memory alloys

The protection of the human muscle-skeletal system from the rapid degradation needs high corrosion resistance biocompatible scaffold materials. Based on this factor, this paper reports the surface morphology, structure and corrosion resistive traits of some multi-walled carbon nanotubes (MWCNTs) coated porous Ti-30 at.%-Ta shape memory alloys (hereafter coded as MWCNT-TTSMAs). The electrophoretic deposition (EPD) technique at various applied voltages was used to coat these alloys with MWCNTs. The structures and morphologies of the prepared samples were characterized at room temperature using the X-ray Diffraction (XRD), energy dispersive spectroscopy (EDS), Raman spectroscopy, Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM) and Transmission Electron Microscope (TEM) measurements. In addition, the corrosion resistance of the coated alloys was assessed via electrochemical impedance spectroscopy (EIS) in the simulated body fluid (SBF) solution. The thickness (increased from 10.05 to 25.93 μm), surface roughness (increased from 1.38 to 1.95 μm) and homogeneity of the coating was significantly affected by the increase in the applied voltages (0 to 50 V). The corrosion rate of the optimum coated specimens was 10 fold lower (0.0966 mm/year) compared to the uncoated one (0.9403 mm/year). The hydrophilic nature of the proposed MWCNT-TTSMAs affirmed their osseointegration potential to support the cell attachments. The mean water contact angle (WCA) of the coated samples indicated a hydrophilic surface with a value of 22° ± 6 compared to the uncoated sample that exhibited a hydrophobic surface with the WCA value of 96°. Thus, the surface of the MWCNTs tends to be hydrophilic, resulting in an improved surface wettability. Antibacterial activity test exhibited that TTSMAs presented minimal inhibition area toward Escherichia coli (E. coli), in contrast, using the MWCNT has shown an improvement in antibacterial performance.

Development and Characterization of Polyester and Acrylate-Based Composites with Hydroxyapatite and Halloysite Nanotubes for Medical Applications.

We aimed to study the distribution of hydroxyapatite (HA) and halloysite nanotubes (HNTs) as fillers and their influence on the hydrophobic character of conventional polymers used in the biomedical field. The hydrophobic polyester poly (ε-caprolactone) (PCL) was blended with its more hydrophilic counterpart poly (lactic acid) (PLA) and the hydrophilic acrylate poly (2-hydroxyethyl methacrylate) (PHEMA) was analogously compared to poly (ethyl methacrylate) (PEMA) and its copolymer. The addition of HA and HNTs clearly improve surface wettability in neat samples (PCL and PHEMA), but not that of the corresponding binary blends. Energy-dispersive X-ray spectroscopy mapping analyses show a homogenous distribution of HA with appropriate Ca/P ratios between 1.3 and 2, even on samples that were incubated for seven days in simulated body fluid, with the exception of PHEMA, which is excessively hydrophilic to promote the deposition of salts on its surface. HNTs promote large aggregates on more hydrophilic polymers. The degradation process of the biodegradable polyester PCL blended with PLA, and the addition of HA and HNTs, provide hydrophilic units and decrease the overall crystallinity of PCL. Consequently, after 12 weeks of incubation in phosphate buffered saline the mass loss increases up to 48% and mechanical properties decrease above 60% compared with the PCL/PLA blend.

Fabrication of Microporous Coatings on Titanium Implants with Improved Mechanical, Antibacterial, and Cell-Interactive Properties.

The success of an orthopedic implant therapy depends on successful bone integration and the prevention of microbial infections. In this work, plasma electrolytic oxidation (PEO) was performed to deposit TiO2 coatings enriched with Ca, P, and Ag on titanium to improve its surface properties and antibacterial efficacy while maintaining normal biological functions and thus to enhance the performance of orthopedic implants. After PEO treatment, the surface of Ti was converted to anatase and rutile TiO2, hydroxyapatite, and calcium titanate phases. The presence of these crystalline phases was further increased with an increased Ag content in the coatings. The developed coatings also exhibited a more porous morphology with an improved surface wettability, roughness, microhardness, and frictional coefficient. In vitro antibacterial assays indicated that the Ag-doped coatings can significantly prevent the growth of both Staphylococcus aureus and Escherichia coli by releasing Ag+ ions, and the ability to prevent these bacteria was enhanced by increasing the Ag content in the coatings, resulting in a maximal 6-log reduction of E. coli and a maximal 5-log reduction of S. aureus after 24 h of incubation. Moreover, the in vitro cytocompatibility evaluation of the coatings showed that the osteoblast (MC3T3) cell integration on the PEO-based coatings was greatly improved compared to untreated Ti and no notable impact on their cytocompatibility was observed on increasing the amount of Ag in the coating. In conclusion, the coating with favorable physicochemical and mechanical properties along with controlled silver ion release can offer an excellent antibacterial performance and osteocompatibility and can thus become a prospective coating strategy to face current challenges in orthopedics.

Improved antifouling and antibacterial properties of forward osmosis membranes through surface modification with zwitterions and silver-based metal organic frameworks

This study investigates the effect of surface functionalization of a thin-film composite forward osmosis membrane with zwitterions and silver-based metal organic frameworks (Ag-MOFs) to improve the antifouling, anti-biofouling, and antimicrobial activity of the membrane. Two types of zwitterions, namely, 3-bromopropionic acid and 1,3-propane sultone, are chemically bonded, with and without incorporation of Ag-MOFs, over the surface of a polyamide membrane. Spectroscopy measurements indicate successful grafting of the modifying agents on the membrane surface. Contact angle measurements demonstrate a notable improvement in surface wettability upon functionalization. The performance of the membranes is evaluated in terms of water and salt fluxes in forward osmosis filtrations. The transport data show demonstrably increased water flux of around 300% compared to pristine membranes, with similar or slightly reduced salt reverse flux. The antifouling and anti-biofouling properties of the modified membranes are evaluated using sodium alginate and E. coli, respectively. These experiments reveal that functionalized membranes exhibit significant antifouling and anti-biofouling behavior, with high resilience against flux decline.

Enhancing the photocatalytic hydrogen production performance of SrTiO3 by coating with a hydrophilic poloxamer

Surface modification is a key strategy for promoting the photocatalytic performance of nanoparticles. In this work, triblock copolymer P123 (PEO-PPO-PEO) has been used as a surfactant in the synthesis of SrTiO3. Instead of removing P123 by annealing after the synthesis process, the photocatalytic performance of P123@SrTiO3 heterostructures was evaluated. Compared with SrTiO3, the hydrophilicity of P123@SrTiO3 has been greatly improved. Poly ethylene oxide and its copolymers have excellent affinity for carriers and contribute to carriers transfer. At the same time, the improvement of surface wettability is beneficial to reduce the adsorption energy of water molecules, which speeds up the frequency at which carriers react with water molecules. As a result, photocatalytic hydrogen production of P123@SrTiO3 reaches as high as 402 μmol·g−1·h−1 in the absence of any cocatalyst, which is 31 times that of pure SrTiO3. However, the specific surface area of P123@SrTiO3 is only 5.2 times that of SrTiO3. P123@SrTiO3 retained high catalytic activity after a long reaction. The construction of surface hydrophilic heterojunction provides a new idea for the design of photocatalytic materials.

Numerical simulation of droplet impact on vibrating low-adhesion surfaces

The impact of droplets on low-adhesion solid surfaces vibrating in the vertical direction was numerically investigated. An axisymmetric multiphase lattice Boltzmann model capable of handling high density and viscosity ratios was implemented to simulate the impact. The effects of vibration parameters on the spreading, contact time, and droplet rebound velocity were addressed. According to the results, the phase angle of the surface vibration is the most dominant factor in determining the dynamics of the droplet upon impact. The contact time generally increases when the surface is vibrated. However, for a certain range of phase angles, the contact time can decrease, as compared to the stationary surface. The rebound velocity also shows a strong dependence on the vibration frequency and phase angle. For droplets with higher impact velocities, the surface vibration becomes a less important factor, whereas on surfaces with lower contact angles, the impact dynamics are much more heavily affected by the surface vibration. The rebound velocity is also heavily affected by surface vibration and varies depending on the frequency and phase angle. This study offers insights into the physics of droplet impact upon vibrating surfaces, which can be utilized to improve surface wettability control in applications where vibration is present.

Ionic liquid based Fluoropolymer solid electrolytes for Lithium-ion batteries

Composite materials based on ionic liquids (ILs) / poly(vinylidene fluoride) (PVDF) and their copolymers have emerged as an interesting approach to develop high ionic conductivity solid polymer electrolytes (SPEs) for lithium-ion battery application.This work reports the development of SPEs based on fluoropolymers, PVDF and poly(vinylidene fluoride co-hexafluoropropylene), PVDF-HFP, containing different ILs: 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([EMIM][TFSI]) and 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]). The influence of IL type and content on the morphological, wettability, physical-chemical, thermal, mechanical and electrochemical properties were evaluated. It is shown that, independently of the polymer matrix, both ILs improve surface wettability and increase the polar β phase content and crystallinity degree of the polymers. The mechanical properties show that the incorporation of IL in the composites results in a plasticizing behaviour.Further, the [BMIM][SCN]/PVDF-HFP with 40 wt% IL content shows the best room temperature ionic conductivity of 0.15 mS.cm−1 with excellent electrochemical stability in the 0.0–5.0 V potential window. The initial discharge capacity value at C/8-rate is 148 mAh.g−1 and 124 mAh.g−1 for the [BMIM][SCN]/PVDF and [BMIM][SCN]/PVDF-HFP composites, respectively, with high coulombic efficiency (98%). At C/8-rate, batteries with [BMIM][SCN]/PVDF-HFP show the lowest capacity fade (16% after 50 cycles) of the prepared composites.Thus, it is demonstrated the suitability of developing SPEs based on IL and fluorinated polymers for the next generation of solid-state room temperature lithium-ion batteries.

Effect of honeycomb porous plate on critical heat flux in saturated pool boiling of highly concentrated artificial seawater

To enhance the reliability of in-vessel retention techniques during a nuclear power plant hazard, the viability of seawater as a coolant to flood the reactor pressure vessel was investigated. Pool boiling of distilled water, 3.5 wt. % artificial seawater, and 7.0 wt. % highly concentrated artificial seawater was performed on a 30-mm-diameter Cu bare surface (BS) with a honeycomb porous plate (HPP). The results revealed an increase in the critical heat flux (CHF) with both artificial seawater solutions, on the BS, when compared with distilled water. The improvement of surface wettability by sea salt deposits was assumed as the main reason for the improvement. A significant enhancement in the CHF was achieved with distilled water and 3.5 wt. % artificial seawater owing to the capillary properties of HPP and the separation of the liquid and vapor phases near the heated surface. When the HPP was employed with 7.0 wt. % highly concentrated artificial seawater, the performance did not improve. Although experiments with a honeycomb solid plate suggested that a high concentration of sea salt can clog the micropores in the HPP walls, resulting in loss of its capillary properties, highly concentrated artificial seawater still presented a better performance than distilled water in all cases investigated.

Air Temperature Measurement and Monitoring Inside Cold Plasma Treatment Reactor for Steel Wire Surface Cleaning Using Fiber Bragg Grating (FBG)

Surface cleaning is one of the critical preliminary process in wire manufacturing surface treatment for the purpose of improved surface wettability and adhesion. However, concern in terms of environmental impacts arises due to common practices of wet-chemicals which led to severe human health. Surface cleaning using cold plasma treatment might become an alternative, but it seems that the issue of gas temperature measurement and monitoring have not been dealt with in depth, since the gas temperature can indicate the type of plasma formed inside the designed reactor. Fiber Bragg grating (FBG) might became an option for gas temperature measurement and monitoring. In this research, air temperature in cold plasma treatment reactor was measured and monitored using FBG, with effects of graphene electrode. Surface roughness of metalwire surface was measured and qualitative observation through optical microscope was carried out, before and after plasma treatment for the purpose of performance evaluation. From the results, it is found that type of plasma discharge formation has been successfully identified through air temperature profiling and monitoring using FBG. Highest surface roughness reduction is performed by filamentary type of discharge of 9 kV applied voltage based on generated air temperature profile by FBG.

Effect of DCSBD plasma treatment distance on surface characteristics of wood and thermally modified wood

This study focused on plasma treatment of European beech (Fagus sylvatica) and heat-treated European beech surfaces with varying distance from the planar electrode of the diffuse coplanar surface barrier discharge. In addition to the treatment in the air, plasma treatment was also carried out in O2, CO2, N2 and Ar atmospheres. Treatment was differentiated between treatment in the active plasma zone and in the so-called plasma afterglow region. Air plasma treatment in the active plasma zone led to the well-known improvement of surface wettability of polar liquids due to increased polar part of surface free energy. Treatment in plasma afterglow region caused the wettability decline of polar liquids and caused a more hydrophobic surface. The phenomenon was primarily present for air plasma treatment. Oxygento-carbon ratio measured by X-ray photoelectron spectroscopy did not change with the treatment in air plasma afterglow. Based on additional tests with pure cellulose paper and based on findings in previous studies, the reason for increased hydrophobicity was suggested to be degradation of hemicelluloses on the wood surface.

F dopants triggered active sites in bifunctional cobalt sulfide@nickel foam toward electrocatalytic overall water splitting in neutral and alkaline media: Experiments and theoretical calculations

As a member of the transition metal sulfide family, cobalt sulfides (CoSx) are considered as highly-activity, cost-effectively, as well as stable electrocatalysts with huge potential for the application of water splitting. Combining experiments and theoretical calculations, we demonstrated that F dopants could activate the Co and S sites of CoS2 in CoS2@NF composites prepared via one-step hydrothermal method and contribute to enhance the intrinsic electrical conductivity, achieving a significantly improved activity of water splitting. The improved surface wettability in F-doped CoS2@NF composites ensures rapid electrolyte penetration and accelerates migration of hydroxyl as well as oxygen release. Furthermore, the F-doped CoS2@NF composites exhibit remarkable electrocatalytic activity and excellent long-term operational stability for overall water splitting in alkaline and neutral media. Predominantly, our work could be explored to enhance and understand the catalytic properties of other transition metal sulfides, and be also expected for further progress achieved with other nonmetal element dopants.

Production of biosurfactant by Bacillus subtilis RSL-2 isolated from sludge and biosurfactant mediated degradation of oil

This study aims to unveil the effect of biosurfactant as stimulant in crude oil bioremediation. Isolated oil-degrading strain, B. subtilis RSL 2 was optimized for the maximum oil degradation and biosurfactant production using Response surface methodology. The produced biosurfactant was characterized and investigated for its effect on microbial oil degradation in two modes (a) sequential and (b) simultaneous. The strain produced 3.5 g/L of biosurfactant at pH 4.0, 25 °C, using 1 g/L crude oil as the only C-source in 7 days, which was characterized as lipopeptide with a critical micelle concentration (CMC) of 0.5 g/L. The biosurfactant improved surface wettability of a hydrophobic substrate i.e. increased surface energy from 30 ± 1 to 35 ± 1 mJ/m2. Further, the simultaneous feed of biosurfactant at 0.5 CMC enhanced oil biodegradation (72%) and biosurfactant production (5.2 g/L) by about 1.6 times than the sequential mode due to improvement in mobilization of oil thus making it more bioavailable.