Wettability Modification Research Articles

Preparation of a Biofunctionalized Surface on Titanium for Biomedical Applications: Surface Properties, Wettability Variations, and Biocompatibility Characteristics

This study developed a promising approach (low-temperature plasma polymerization with allylamine) to modify the titanium (Ti) surface, which helps the damaged tissue to heal faster. The Ti surface was first cleaned by argon (Ar) plasma, and then the functional amino-groups were coated on the Ti surface via plasma polymerization. The topography characteristics, wettability, and optimal plasma modification parameters were investigated through atomic force spectroscopy, secondary ion mass spectroscopy, and response surface methodology (RSM). Analytical results showed that the formation of a porous surface was found on the Ar plasma-modified Ti surfaces after Ar plasma modification with different parameters. The Ar plasma modification is an effective approach to remove surface contaminants and generate a porous topography on the Ti surface. As the Ti with Ar plasma modification was at 100 W and 190 m Torr for 12 min, the surface exhibited the maximum hydrophilic performance. In the allylamine plasma modifications, the contact angle values of the allylamine plasma-modified Ti surfaces varied between 70.15° and 88.26° in the designed parameters. The maximum concentration of amino-groups (31.58 nmole/cm2) can be obtained from the plasma-polymerized sample at 80 W and 150 mTorr for 22 min. Moreover, the cell response also demonstrated that the allylamine plasma-modified Ti sample with an optimal modification parameter (80 W, 22 min, and 150 mTorr) possessed great potential to increase cell adhesion ability. Thus, the optimal parameters of the low-temperature plasma polymerization with allylamine can be harvested using the RSM design. These data could provide new scientific information in the surface modification of Ti implant.

Exponential promotion and suppression of bubble nucleation in carbonated liquid by modification of surface wettability

When carbon dioxide is supersaturated in a liquid, carbon dioxide gas gets nucleated, expands, and floats on the surface of the liquid. This is a well-known phenomenon and is generally observed in carbonated drinks. This bubble generation phenomenon can be activated or suppressed by changing the properties of the solid surface in contact with the carbonated liquid. In this study, a method of exponentially increasing or suppressing the bubble generation of carbonated liquids by modifying the surface wettability is proposed. Equal amounts of carbonated liquid were poured into bare, superhydrophilic, and superhydrophobic cups to compare the amount of overflow and generated gas. In the superhydrophobic cup, bubbles were generated only at the start of pouring the carbonated liquid, after which no more bubbles were generated. When the same amount of liquid was poured into the bare cup, about 4.1% of the total mass overflowed, while in the case of superhydrophilic surfaces, about 34% overflowed. The generated gas from each cup also showed significant difference according to the surface properties. From the experimental results, it was concluded that the superhydrophobic surface can suppress bubble nucleation, thus, preventing the soda from overflowing. Furthermore, a fall in carbon dioxide concentration can be prevented.

Immobilisation of synthesised TiO2 nanosheets onto the surface of the mesh and its modification effect on the wettability behaviour

ABSTRACT In this study, a widely used TiO2 was synthesised by a simple hydrothermal solution and was characterised by using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Analytical results showed that the synthesised TiO2 was in anatase form and consisted of well-defined sheet-shaped structures having a rectangular outline. Moreover, the calcination temperature remarkably affected the crystalline phase of the product as a mixture of rutile and anatase phase was obtained with the product calninated at 1000°C. The synthesised TiO2 was further involved in a coated process using stainless mesh as a subtract. The contact angle measurement revealed a modification on the surface wettability of the mesh with the underwater oil contact angle larger than 150 ° and the oil/water separation efficiency over 90% even after thirty cycles of reuses. The substrate analysis indicated that the TiO2 made a separating layer thus, affected the wettability behaviour of the mesh. Moreover, the TiO2 coated mesh maintained excellent underwater superoleophobicity behaviour after immersed in corrosive solutions for 5 days. The present study suggested the effectiveness of immobilising synthesised TiO2 for the modification of surface wettability.

Polymer-functionalized silica nanoparticles for improving water flood sweep efficiency in Berea sandstones

Extraction of oil trapped after primary and secondary oil production stages still poses many challenges in the oil industry. Therefore, innovative enhanced oil recovery (EOR) technologies are required to run the production more economically. Recent advances suggest renewed application of surface-functionalized nanoparticles (NPs) for oil recovery due to improved stability and solubility, stabilization of emulsions, and low retention on porous media. The improved surface properties make the NPs more appropriate to improve microscopic sweep efficiency of water flood compared to bare nanoparticles, especially in challenging reservoirs. However, the EOR mechanisms of NPs are not well understood. This work evaluates the effect of four types of polymer-functionalized silica NPs as additives to the injection water for EOR. The NPs were examined as tertiary recovery agents in water-wet Berea sandstone rocks at 60 °C. The NPs were diluted to 0.1 wt. % in seawater before injection. Crude oil was obtained from North Sea field. The transport of NPs though porous media, as well as nanoparticles interactions with the rock system, were investigated to reveal possible EOR mechanisms. The experimental results showed that functionalized-silica NPs can effectively increase oil recovery in water-flooded reservoirs. The incremental oil recovery was up to 14% of original oil in place (OOIP). Displacement studies suggested that oil recovery was affected by both interfacial tension reduction and wettability modification, however, the microscopic flow diversion due to pore plugging (log-jamming) and the formation of nanoparticle-stabilized emulsions were likely the relevant explanations for the mobilization of residual oil.

Role of roughness levels induced by the laser texturing on the wettability behaviour of ABS

The development of patterned surfaces to induce different wettability behavior on industrial components has recently gained attention due to their potential applications, for example anti-icing, anticondensation and superoleophobicity, among others. However, limited semi empirical studies have been reported on the study of a general predictive formula that considers all possible wetting states of a droplet.This study is focused on validating a theoretical expression as a predictive tool for future wettability modification based solely on the surface topography variation using experimental data. Understanding the effects of surface modifications, produced by direct ultrashort laser texturing on the wettability properties of Acrylonitrile Butadiene Styrene (ABS) is wanted. The present study is a preliminary work that will be as an introduction for future studies regarding the wettability modification of different thermoplastics.

The use of cooling and anti-solvent precipitation technique to tailor dissolution and physicochemical properties of meloxicam for better performance

Low dissolution rate of pharmaceutical agents with poor water-solubility limits their bioavailability after oral administration. These two parameters are pivotal when a fast onset of action required which could be the case for meloxicam (MLX), an anti-inflammatory and pain reliever compound. In the present study, the effects of various solvents and method of crystallization were investigated to modify the physicochemical properties and dissolution of MLX crystals. X-ray diffractometry, infrared spectrophotometry and differential scanning calorimetry were used to investigate the crystalline characteristics of the particles. Dissolution, particle size, solubility, contact angle and morphology of crystals were also evaluated. It was found that the type of solvent and crystallization methods modified the shape of crystals from polyhedral irregular to prismatic particles. The results ruled out any polymorphic changes occurred during the processes for most samples. The dissolution rate of MLX was improved by recrystallization and the best dissolution performance was observed for crystals prepared by anti-solvent precipitation in the presence of acetone, ethanol, and propanol with a 2-3-fold increase in dissolution efficiency than that of the parent drug. This could be related to the decreased particle size, lower contact angle, improved wettability and crystalline modifications.

Modification of Carbon-Nanotube Wettability by Ion Irradiation

The results of investigating the wettability of commercial multi-walled carbon nanotubes (MWCNTs) Taunit-MD under irradiation with 120-keV Ar+ ions with various fluences are presented. The structure of the irradiated MWCNTs is investigated using Raman spectroscopy, scanning electron microscopy, and X-ray microanalysis of the samples. The dependences of the average diameter of the MWCNTs, the O2 concentration, and defects in the MWCNT samples on the irradiation fluence, as well as their effect on the wettability with distilled water, ethylene glycol, and cyclohexane are considered. The possibility and prospects of using ion-beam modification methods for controlled variation of the wettability with the aim of creating a MWCNT coating, which is hydrophobic or hydrophilic to various types of liquids, are discussed.

Wettability modification and its influence on methane adsorption/desorption: A case study in the Ordos Basin, China

AbstractWettability modification of coal rock may cause serious change in the methane adsorption/desorption behaviors. Thus, the contact angle measurement and isothermal adsorption/desorption experiment of raw coal and samples treated with surfactants (STS) were conducted to investigate the wetting properties and methane adsorption/desorption characteristics. The results indicated that the long‐flame coal (LFC) has the good hydrophilicity itself, and there was no evident sign of saturated adsorption for different samples at relatively low‐pressure (<8 MPa) stage. The sample treated with the wettability reversal agent (G502) had the larger methane adsorption capacity than the wetted samples (LAS, JFC, and 6501), with the latter facilitating the methane desorption. Additionally, the adsorption capacity of the air‐dried samples was stronger than that of the water‐containing samples, including the moisture‐equilibrated, LAS, JFC, and 6501, reflecting that the better the hydrophilicity, the weaker the methane adsorption. Besides, the desorption hysteresis rate of the same sample was mainly controlled by pressure, i.e. the desorption hysteresis indicated a logarithmic decrease with the increasing pressure, but the STS clearly showed the desorption hysteresis to varying degree due to the wettability differences. The pressure drop in the low‐pressure stage was difficult to drive the adsorbed methane to immediately desorb from the matrix surface, whereas even caused further adsorption or re‐adsorption, meaning that the coal required a greater depressurization to enter the effective desorption stage. Finally, the positive implications of wettability modification including enhancing CBM recovery, as well as coal and methane outburst prevention and coal dust control in the mining industry were discussed.

The role of fines transport in low salinity waterflooding and hybrid recovery processes

Low Salinity Waterflooding (LSW) is a promising technology for improving oil recovery in secondary and tertiary stages over the conventional waterflooding (HSW). As widely reported in the literature, this emerging recovery approach has relatively low operating costs and is more environmentally-friendly than conventional Enhanced Oil Recovery (EOR) methods. In fact, LSW is a multi-physics recovery process; however, most of the previous studies focused on wettability modification as the sole mechanism for the incremental oil recovery by LSW. Unfortunately, these studies often ignored other crucial factors that importantly affect the performance of LSW, e.g., fines transport under a low salinity injection environment.This paper introduces a robust modeling workflow to capture important recovery mechanisms occurred in LSW by integrating fines migration, wettability alteration, and geochemistry. The results showed that fines transport including fines deposition, fines migration, and fines plugging plays an important role in LSW process. Fines plugging by LSW can cause formation damage, but it also can be used as a mobility control agent. The LSW model equipped with fines transport shows an excellent agreement for incremental oil recovery and pressure drop against laboratory coreflooding. Finally, a novel concept of hybrid low salinity assisted gas flooding was proposed to overcome the existing technical challenges associated with the conventional CO2 flooding.

Ridge-Texturing for Wettability Modification by Using Angled Fine Particle Peening

The industrial demand for wettability control has been increasing because wettability is a key factor for achieving novel anti-contaminant surfaces and related products. In this paper, the potential of angled fine particle peening (angled-FPP) was explored as a method of surface modification to control wettability. Angled-FPP, which is an abrasive jet machining process conducted using a peening nozzle set at an angle inclined to the material surface, is a potential texturing technique. With it, it is possible to create periodically aligned peaks and valleys (“ridges”) on the peened surface. Because control of wettability could possibly be achieved by varying the geometric characteristics of the texture, an attempt was made to vary ridge texture by conducting angled-FPP using three kinds of shot particles: steel, glass, and alumina grit. Thereafter, changes in the wettability owing to creation of a ridge texture on the surfaces were evaluated, with focus on the geometric and morphological features of the ridge texture. The results indicate that the size of the ridges depends on the size and shape of the shot particles, and the angled-FPP conducted using finer angular particles created densely concentrated ridges. The superficial appearance of the ridge texture differed depending on the shot particles used for angled-FPP. The topographies created by angled-FPP using steel particles and alumina grit were “hierarchical” (i.e., the ridge structure was overlapped by finer-scale roughness). In contrast, angled-FPP conducted using glass particles created ridge structure with a quite plain surface. Measurement of the water drop contact angle revealed that the surface became less hydrophilic after creation of the hierarchical topography. It was concluded that the predominant influence on the wettability of the angled-FPP surfaces came from the superficial morphology of the ridge texture.

Branched polymers and nanoparticles flooding as separate processes for enhanced oil recovery

Since it was first theorized more than half-century ago, nanotechnology has proven to be the perfect boost for existing technologies and the oil industry has made use of this avant-garde discipline to upsurge the productivity of mature oilfields. With respect to polymer flooding, recent research has stressed the importance of the (macro)molecules’ architecture on the physical properties. This paper presents the numerical simulation of these two agents in standard, not combined, oil recovery processes. The polymer solution viscosity is calculated considering the polymer’s architecture, its degradation and the salinity. The nanoparticles affect the carrier-phase viscosity and the rock formation wettability, which modifies the oil mobility. Results evidenced the improved capabilities of branched (i.e. star/comb) polymers with respect to traditional linear ones. The modified architecture improves not only the rheological but also the viscoelastic properties, which ultimately increases the microscopic sweeping efficiency. Nanoparticles increase slightly the carrier phase viscosity, but their main recovery mechanism is their adsorption onto the rock and subsequent wettability modification, reducing the residual oil saturation. Furthermore, it is also important to properly characterize both the particles’ average size and also their aggregation rate, since these affect the recovery efficiency. Simulations show the importance of a good characterization of oil recovery agents and their effect on the phases’ physical properties as well as the potential of nanoparticles to act as a boost of traditional enhanced recovery processes.

Fabrication of controllable wettability of crystalline silicon surfaces by laser surface texturing and silanization

This paper aims to explore the effects of laser surface texturing and chemical modifications by silanization on the wettability of silicon surfaces. To effectively prepare super-hydrophobic surfaces on silicon, a process using laser texturing with following silanization treatment is used to modify the surface. The surface wettability is evaluated by water contact angle (WCA). To ascertain the effect of laser texturing on wettability, the morphological and metallurgical modifications of the surface were investigated by scanning electron microscopy (SEM), white light confocal microscope and X-ray photoelectron spectroscopy (XPS). It is found that the fresh laser-processed silicon surface is super-hydrophilic, which is in line with the Wenzel model. A super-hydrophobic surface with a WCA >150° was successfully obtained after silanization treatment. Silanization by a concentration of 0.72 wt% 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane with 2 h of immersion time was found to be the most effective condition for achieving super-hydrophobic silicon surfaces. The effects of acids, alkalis and salts on wettability have also been assessed. The results indicate that as-prepared silicon samples with a fluoride coating can be normally used in acid condition but not suitable for use in alkaline and salty environments.

Low salinity water flooding in carbonate reservoirs – dissolution effect

One of the most significant research subjects in the industry of oil is the low salinity water injection techniques (LSWI). This is because there are possible benefits of raising recovery in oil as opposed to the conventional injection of seawater. Recent research has been done to find out the causes of less salinity with the injection of water in carbonated rocks presented significant findings. The primary mechanisms that are thought to lower salinity water injection are carbonate rocks dissolution, fines migration and alteration of wettability to more water wet. However, many researchers have elected to oppose the mechanism of dissolution and instead attributed high recovery of oil to be the primary wettability modification mechanism. Additionally, previous researchers provided no evidence characterizing about the rock and fluids produced in a detailed manner. This research work provides a detailed description of the underlying mechanisms, the core flood laboratory and the spontaneous imbibition in carbonate rocks. In the experiment, we carried out a series of steps using a limestone core with low permeability. This core was obtained from a nearby oilfield in Iraq and used it to study how dissolution and fines migration mechanisms take place. Moreover, in the process of carrying out the experiment and before its starting, SEM imaging analysis was used. In this case, as we carried out the experiment, we had to inject two-phase flow of sea water (SW), de-ionized water (DW) as well as soltrol-130. This was done in a sequential manner at 50 °C as well as 0.02 ml per minute. As the experiment progressed, the concentration of ions and pH value of the extracted water were measured in a continuous manner. The results obtained indicate that the rate of change in concentration of Ca2+ ions is directly proportional to the effluent pH value. By just balancing the mass, we were able to easily see the rate at which limestone dissolved as the experiment progressed. The maximum increase in pH was registered when fresh water was injected (pH=9.2). An increase in pH value can have a positive effect on altering wettability in that it can increase the alkalinity of flood water. To notice fines migration, the Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) are used to scan the images of the inlet and outlet of the core plugs after completion the experiment. This method can indicate that dissolution can induce fines dislodgement for the surface of the rock. The two mechanisms of fine migration and carbonate rock dissolution can significantly increase recovery of oil and at the same time inject water low in salinity.

Wettability Alteration of Quartz Surface by Low-Salinity Surfactant Nanofluids at High-Pressure and High-Temperature Conditions

Advanced low-salinity aqueous formulations have shown promising results for rock wettability modification and interfacial tension reduction. Additives, such as surfactant and nanoparticles, can be ...

Solution-processed organic light-emitting diode in high-resolution line patterns by scalable wetting modification

Abstract We report a simple and cost-effective method of producing high-resolution line patterns of a solution-processed organic light-emitting diode (S-OLED) in the bank structures through the scalable wetting modification. The pattern resolution depends primarily on the subtle interplay between the geometric capillary action and the wetting property of the OLED solution. According to the Cassie-Baxter model, the air-pockets in the bank structures (BSs) on the substrate serve as the dewetting regions, repelling the hydrophilic solution, so that the nature of the BS surface should be precisely tuned for constructing high-resolution patterns. The wettability of the BS surface is predominantly modified by the amount of the functional group under ultraviolet ozone to achieve the Cassie penetrating wetting state which is rather hydrophilic. The OLED solution is then uniformly filled in the groove between two adjacent BSs to reach a feature size of 5 μm in line pattern. Our patterned S-OLED, fabricated using the scalable wettability modification, exhibits the good stability and uniformity without any degradation in electroluminescent performance in relative to the non-patterned device during the operation.

Destabilization of fine solids suspended in oil media through wettability modification and water-assisted agglomeration

Removing fine solids suspended in aqueous or oil media is crucial in many chemical, petroleum and environmental engineering processes with ever-increasing demands on improving product quality and meeting waste management standard. In oil industry, the removal of fine mineral solids is required to achieve high-quality oil products but remains a great challenge. This difficulty is due to hydrophobic and oleophilic nature of the mineral matters and small dimension of fine particulates. Here we introduce a two-step agglomeration method to destabilize bitumen-coated silica particles in cyclohexane by simply modifying their surface wettability using the amphiphilic polymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG), and then adding a small amount of water to trigger the formation of large particle aggregates. By sedimentation tests, we demonstrate that the two-step method can significantly enhance settling rate of the particles and reduce content of residual solids in the supernatant simultaneously. The underlying physical interaction mechanisms have been investigated using atomic force microscope (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D). The results suggest that PEG-PPG-PEG can readily adsorb to the bitumen-coated silica surface, thereby altering the surface from hydrophobic to hydrophilic and tuning its interaction with added water drops from repulsion to attraction in cyclohexane. This work provides useful insights into the development of effective strategies of removing suspended fine solids from oil media in petroleum production processes.

Effects of geochemistry and interphase transport of CO2 on hybrid carbonated low salinity waterflood to improve oil recovery and CO2 sequestration

AbstractThe hybrid process of carbonated low salinity waterflood (CLSWF) integrating low salinity waterflood (LSWF) and carbonated waterflood (CWF) is proposed as enhanced oil recovery (EOR) incorporating CO2 storage. Based on the understanding of the mechanisms of LSWF and CWF, the hybrid technology is simulated with a fully‐coupled model of fluid flow, geochemical reactions, and equation of state, which describes chemical interactions in the oil/brine/rock system. The comprehensive simulations confirm the synergetic effects of the hybrid CLSWF when compared to waterflooding (WF) and LSWF. In addition, optimum designs of cost‐efficient CLSWF securing CO2 storage are drawn via optimization and sensitivity studies. First, CLSWF enhances wettability modification effect, when compared to LSWF. In CLSWF, extensive mineral dissolution causes more cation exchange. Following the multicomponent ion exchange theory of the wettability modification mechanism, CLSWF produces more residual oil than LSWF with an increasing equivalent fraction of cation. Consequently, it enhances oil recovery by 6.9% and 2.5%, compared with WF and LSWF. Second, the interphase transport of CO2 introduces the oil viscosity reduction effect, which improves the injectivity of CLSWF. Lastly, it sequestrates 25% of the injected CO2 in the depleted reservoir via the solubility‐trapping mechanism. In optimization and sensitivity studies, the optimum design of CLSWF is determined to produce more oil recovery by 9.9% and more net present value by 35% over WF. In addition, 33% of the injected CO2 becomes sequestrated in the reservoirs. This study clarifies that hybrid CLSWF improves EOR, injectivity, and CO2 storage. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Modification of Interfacial Tension and Wettability in Oil–Brine–Quartz System by in Situ Bacterial Biosurfactant Production at Reservoir Conditions: Implications for Microbial Enhanced Oil Recovery

Modification of oil–brine–minerals interfacial properties with biosurfactant-producing microorganisms and their extracellular metabolites has been considered as one of the viable strategies for mic...

A novel method for surface wettability modification of talc through thermal treatment

Silica tetrahedron (also called siloxane) is an important structure of clay minerals, the percentage of which influences the hydrophobicity, polarity and other surface properties on clay mineral surfaces. In this study, a novel method for surface wettability modification of talc through thermal treatment has been put forward. In this method, the symmetrical siloxane structures on talc basal surfaces were broken by transforming the nonpolar siloxane structure into a polar structure during the thermal treatment process, thus to decrease the hydrophobic components on talc surfaces, and therefore achieve the goal of surface wettability modification. This study was performed through the measurements of thermosgravimetric analysis and differential scanning calorimetry (TG-DSC), contact angle and wetting heat measurements, fourier transform infrared spectroscopy (FTIR), and 29Si-nuclear magnetic resonance spectroscopy (29Si NMR) as well as molecular dynamic simulations (MDs). The results indicate that the thermal treatment at 960 °C for only a very short time could greatly decrease the contact angle of water on talc surfaces. The mechanism could be attributed to that the thermal treatment leads to the disorder of some of the SiO bond length and O-Si-O bond angle in talc silica tetrahedron structure, which finally results in the disorder of the symmetrical siloxane structure and the formation of the amorphous silica phase. And the decrease of hydrophobic siloxane structures on talc surface gives rise to the relatively strong hydrophilicity on talc surfaces. This current method improves the wettability of talc without any addition of modifiers, which would be helpful of many applications of clay minerals, such as clay-polymer composites, filler materials, clay mineral dispersion in aqueous suspensions or mineral processing, etc.

Femtosecond laser pulse inducing hydrophilicty and hydrophobicity on polycarbonate surfaces

This study investigated the use of ultrashort femtosecond laser pulses to induce either hydrophilic or hydrophobic surfaces on polycarbonate (PC). It has been observed that controlled modification of wettability could be achieved over a wide range of the water contact angle from below 5° to above 150°. It has been shown that the pulse energy fluence and total energy deposition onto PC are the important factors in determining the laser–PC interaction and therefore the different level of wettability on PC surface. X-ray photoelectron spectroscopy-spectra measurement indicates that the modification was caused dominantly by laser induced chemical bond changes. The changes in surface morphology may not noticeably contribute to the surface wettability. The results would be useful in microfluidics chip design and fabrication with controlled surface wetting properties.