Controlling Microdroplet Inner Rotation by Parallel Carrier Flow of Sesame and Silicone Oils

We developed a method for passively controlling microdroplet rotation, including interior rotation, using a parallel flow comprising silicone and sesame oils. This device has a simple 2D structure with a straight channel and T-junctions fabricated from polydimethylsiloxane. A microdroplet that forms upstream moves into the sesame oil. Then, the largest flow velocity at the interface of the two oil layers applies a rotational force to the microdroplet. A microdroplet in the lower oil rotates clockwise while that in the upper oil rotates anti-clockwise. The rotational direction was controlled by a simple combination of sesame and silicone oils. Droplet interior flow was visualized by tracking microbeads inside the microdroplets. This study will contribute to the efficient creation of chiral molecules for pharmaceutical and materials development by controlling rotational direction and speed.

Characterizing Oligomeric Hydroxyl Silicon Oils by MALDI-TOF MS With the Pyridine-Modified Matrix

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) is a powerful technique for analysis of various polymers, but it is still very difficult to characterize silicone oil due to its poor ionization efficiency. In this work, oligomeric hydroxyl silicone oils were successfully characterized by MALDI-TOF, by using pyridine-modified 2,5-dihydroxylbenzoic acid (DHB) as the matrix. Furthermore, the mixed crystal of DHB and hydroxyl silicone oil was analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), and the analytical results verified that modification with pyridine could remarkably improve the solubility of hydroxyl silicone oil in DHB, leading to the enhancement of its ionization efficiency in MALDI. The analysis of the MS spectra of a series of hydroxyl silicone oils indicated that they tended to be ionized by the attachment with Na+, and the average molecular weight and the degree of polymerization were measured for several oligomeric hydroxyl silicon oils.

Thiolated Silicone Oils as New Components of Protective Creams in the Prevention of Skin Diseases

This work investigates the possibility of using thiolated silicone oils as new components in protective creams and their impact on the efficacy of these products. Thiolated silicone oils were synthesized by amide bond formation between primary amino groups of poly17dimethylsiloxane-co-(3-aminopropyl)-methylsiloxane] and carboxylic groups of thiol ligand (3-mercaptopropionic acid) with carbodiimide as a coupling agent. To evaluate and compare the properties of these kinds of thiomers, three different emulsion o/w types were obtained. Emulsion E1 contained methyl silicone oil, E2 poly[dimethylsiloxane-co-(3-aminopropyl)-methylsiloxane], and E3 thiolated silicone oil (silicone-MPA), respectively. Physicochemical properties, including pH, conductivity, droplet size distribution, viscosity, and stability, were assessed. The efficacy of barrier creams in the prevention of occupational skin diseases depends on their mechanical and rheological properties. Thus, the method which imitates the spreadability conditions on the skin and how structure reconstruction takes places was performed. We also investigated textural profile, bioadhesion, protection against water and detergents, and water vapor permeability. Emulsion E3 was characterized by beneficial occlusion, spreadability, and adhesion properties. These features with prolonged residence time on the skin can make designed barrier creams more preferable for consumers.

The Compatibility of Three Silicone Oils with Polydimethylsiloxane and the Microstructure and Properties of Their Composite Coatings

The compatibility of three types of silicone oil with polydimethylsiloxane, the phase separation of their mixture and the microstructure and properties of their composite coatings were investigated. The existing form of silicone oil in the coating and the precipitation behavior were also studied. The compatibility observed experimentally of the three silicone oils with PDMS is consistent with the results of the thermodynamic calculation. The silicone oil droplet produced by phase separation in the mixture solution can keep its shape in the cured coating, also affecting the microstructure and mechanical properties of the coating. It was found that methyl silicone oil and methyl fluoro silicone oil do not precipitate on the surface, and they have no effect on the surface properties of the coating. In contrast, phenyl silicone oil has obvious effect on the surface, which makes the water contact angle and diiodomethane contact angle of the coating decrease significantly.

Removal of Silicon Oil from the Vitreous Cavity via the Anterior Chamber. Eight Years of the Author’s Experiences

Purpose: To evaluate usefulness and safety of removal of silicone oil from the vitreous cavity via the anterior chamber. Methods: The procedures were performed between 2012 and 2020 in 31 patients who required endotamponade with the use of light silicone oils. In most of the patients, the procedure was combined with cataract removal, secondary lens implantation or transscleral fixation of an artificial lens. A passive bimanual technique was used to replace silicone oil with fluid. Results: The procedure to remove silicon oil via the anterior chamber proceeded without serious intra- and postoperative complications. There were no hypotony observed in first postoperative day. Conclusion: Patients eligible for the procedure are those who have preoperative indications for silicone oil removal and whose removal path via the anterior chamber is not associated with a special need to remove the lens from the eye.

Improved Magnetorheological Properties by Using Ionic Liquid as Carrier Liquid of Magnetorheological Fluids

The interface between the particles and the carrier fluids has an important influence on the performance of magnetorheological fluid (MRF). In this study, ionic liquids and silicone oils with the same viscosity and different surface tensions were used as carrier fluids to prepare two different carbonyl iron powder (CIP) magnetorheological fluids. The rheological properties of the two magnetorheological fluids were evaluated by the MCR301 rotating rheometer. The experimental results indicate that ionic liquid-based MRF showed higher shear yield strength and more significant MR effect than silicone oil-based ones in higher magnetic field strength. A possible explanation was proposed and proved through experimental data analysis.

Silicone oil: physical properties and clinical use (a literature review)

Introduction. In modern vitreoretinal surgery, silicone oil is used for replacing the vitreous body during vitrectomy. This surgery is performed to treat retinal detachment, proliferative retinopathy, giant retinal tears and severe eye injuries. In this regard, it seems especially relevant to provide a description of the physical characteristics of silicone oils that determine the choice of surgeons.Purpose. To study indications for the use of silicone oil tamponade as well as possible complications associated with its use based on a literature review and own research.Materials and methods. We analyzed literature on PubMed, eLibrary, and Medline over the past 30 years. Overall, 34 sources of literature were reviewed, including results of our own clinical studies.Results. Literature review has shown that silicone oils are very useful as a permanent tamponade. Although gas tamponade can be used for giant retinal tear management, silicone oils are used for minimizing the risk of post-surgical bleeding and reattach detached retinas in case of severe eye injuries. One of the main issues related to the use of silicone oils is the post-surgical increase in IOP. To reduce the risk of such complication, we have proposed methods of infusion and optimal schedule of silicone oil removal.Conclusion. Silicone oil is the optimal choice for treating most retinal diseases and improving their prognosis. An important criterion for choice of silicone oil is the time that is required for tamponade.