Temperature and pH Responsive Janus Silica Nanoplates Prepared by the Sol-Gel Process and Postmodification

Preparation and Investigation of Temperature-Responsive SiO2-PSBMA Janus Nanosheet with Salt-Tolerant Properties for Enhanced Recovery of Heavy Oil

Enhancing heavy oil recovery is crucial to ensuring stable crude oil production. The development of stimulus-responsive Janus Pickering emulsifiers tailored for a reservoir environment has garnered significant attention in the field of reservoir production, emerging as a promising alternative to traditional surfactants. In this study, silica-based Janus nanosheets with temperature-responsive properties (OH-SiO2-PSBMA JNs) are synthesized using sol-gel process and atom transfer radical polymerization (ATRP) method. Experimental observations reveal that OH-SiO2-PSBMA JNs (0.1 wt %) can effectively reduce the interfacial tension (IFT) between heavy oil and water to 23.24 mN/m. Additionally, these nanosheets exhibited excellent emulsifying ability, forming stable emulsions with an average particle size of only 35 μm at a mass fraction of 1 wt % and demonstrating good salt tolerance (Salinity value: 1.51 × 104 mg/L). Furthermore, OH-SiO2-PSBMA JNs exhibited a temperature response that is well-suited for the reservoir environment, effectively stabilizing heavy oil emulsion at a high temperature (65 °C) and facilitating oil-water separation at a lower temperature (25 °C). These excellent properties of nanosheets contributed to obtaining an additional 13.2% recovery rate at low concentration (0.03 wt %). These results indicated that OH-SiO2-PSBMA JNs had the potential for enhanced oil recovery (EOR) application.

Advanced Switchable Molecules and Materials for Oil Recovery and Oily Waste Cleanup

Advanced switchable molecules and materials have shown great potential in numerous applications. These novel materials can express different states of physicochemical properties as controlled by a designated stimulus, such that the processing condition can always be maintained in an optimized manner for improved efficiency and sustainability throughout the whole process. Herein, the recent advances in switchable molecules/materials in oil recovery and oily waste cleanup are reviewed. Oil recovery and oily waste cleanup are of critical importance to the industry and environment. Switchable materials can be designed with various types of switchable properties, including i) switchable interfacial activity, ii) switchable viscosity, iii) switchable solvent, and iv) switchable wettability. The materials can then be deployed into the most suitable applications according to the process requirements. An in-depth discussion about the fundamental basis of the design considerations is provided for each type of switchable material, followed by details about their performances and challenges in the applications. Finally, an outlook for the development of next-generation switchable molecules/materials is discussed.

Stimuli-Responsive Proteinosomes Based on Biohybrid Shell Cross-Linked Micelles

A new method of stimuli-responsive proteinosome fabrication with the shell cross-linked micelle as a template is reported in this research. A thermoresponsive diblock copolymer poly[di(ethylene glycol) methyl ether methacrylate]-b-poly[poly(ethylene glycol) methyl ether methacrylate-co-pyridyl disulfide methacrylamide] [PDEGMA-b-P(PEGMA-co-PDSMA)] was synthesized and self-assembled into micelles with PDEGMA cores and P(PEGMA-co-PDSMA) shells at the temperature above its lower critical solution temperature (LCST). Reduced bovine serum albumin (BSA) molecules with six thiol groups were used to cross-link the shells of the micelles by reacting with the pendant pyridyl disulfide groups on the P(PEGMA-co-PDSMA) block. At a temperature below the LCST of the polymer, the PDEGMA cores were dissolved in water, affording proteinosomes with a size of about 50 nm and capsule-like structures. The proteinosome was also thermoresponsive with a phase transition temperature at 35 °C. The fabrication of the proteinosome had no obvious influence on the structure and activity of BSA, and BSA retained most of its secondary structure and esterase-like activity. Because the BSA molecules were connected to the polymer chains through disulfide bonds, they could be released upon addition of dithiothreitol. The in vitro cell viability evaluation and the cellular uptake assay demonstrated that the proteinosome showed low toxicity to NIH 3T3 and 4T1 cells and could be internalized into the 4T1 cells.

Preparation of ionogel-bonded mesoporous silica and its application in liquid chromatography

A new preparation strategy for stable ionogels on silica obtained by a chemical bonding method and its application in LC.