Functional Janus-SiO₂ Nanoparticles Prepared by a Novel “Cut the Gordian Knot” Method and Their Potential Application for Enhanced Oil Recovery

Abstract

Currently available methods (e.g., interfacial protection and phase separation) for preparing Janus nanoparticles are often complex and expensive. Furthermore, the preparation of Janus nanoparticles with a particle size below 10 nm is challenging. In this work, we combine an in situ surface-modification route with a chemical etching route to establish a novel “cut the Gordian knot” method for the preparation of functional Janus-SiO2 nanoparticles. Hydrophobic SiO2 nanoparticles with a three-dimensional network structure prepared via an in situ surface-modification route were dispersed in NaOH solution containing surfactant or ethanol to enable corrosion close to the modifier–nanoparticle interface with a relatively low content of surface modifiers. Thus, amphipathic Janus-SiO2 nanoparticles with a hydrophilic surface containing Si–OH species and a hydrophobic surface containing −CH3 fragments were generated. The as-prepared Janus-SiO2 nanoparticles with a size of 4–9 nm and a specific surface area of up to 612.9 m2/g can be easily dispersed in water, and they also can transfer from the water phase to the oil phase by tuning the surface polarity. Moreover, they can be tuned to achieve bidirectional regulation of surface wettability plus a reduction of the oil/water interface tension. Hence, a significant reduction (by 33∼50%) of water injection pressure and an enhanced oil recovery (EOR) (by 21.1% ∼ 26.6%) can be achieved. Apart from that, Janus-SiO2 nanoparticles are able to increase the viscosity of partially hydrolyzed polyacrylamide by 282.9% and significantly decrease its viscosity loss ratio in brine, causing an EOR of about 36.6%. With simple, low-cost, and scalable procedures, the following approach could be well applicable to fabricating Janus-SiO2 nanoparticles with a high potential for augmented water injection as well as EOR of low-permeability reservoirs.

Potential Application of Fe2O3 and Functionalized SiO2 Nanoparticles for Inhibiting Asphaltene Precipitation in Live Oil at Reservoir Conditions

“…Therefore, they have a superior performance over conventional micro/macromaterials which offer prospective applications in oil and gas fields . Nanoparticles/nanofluids have been applied to resolve issues in different sections of the petroleum industry such as drilling fluid enhancement, − gas hydrate production, , and enhanced oil recovery (EOR). − …”

Nanoporous Silica Nanoparticles with Janus Functionalization for Enhanced Cell Uptake and Drug Delivery

“…Despite their unique advantages, there are several shortcomings for biomedical applications. First, the synthesis of colloidal Janus nanoparticles of <50 nm is challenging, and most of reported methods produce Janus structures of >100 nm size. − However, cellular and subcellular targeting requires particle sizes in the range of 5–50 nm . Second, characterization of Janus structures at the <50 nm regime that occurs due to anisotropic surface chemistry and anisotropic functionalization is challenging due to the requirements of sophisticated chemical characterization at such length scales.…”

Amphiphilic Bowl-Shaped Janus Particles Prepared via Thiol–Ene Click Reaction for Effective Oil–Water Separation

“…Considerable endeavors have been devoted to effectively separating floating and dispersed oils by controlling the surface wettability of superwettable materials [ 5 , 6 , 7 , 8 , 9 ]. Recently, superhydrophobic ceramic membrane and nanosheet materials have become new types of materials that can separate slick oil and stable oil droplets [ 10 , 11 , 12 ]. However, an effective surfactant-free separation method for micro-fine oil droplets has not been achieved thus far.…”