Silicone Oil Content Research Articles

Synthesis and Application of Dendritic Waterborne Polyurethane with Long Alkyl Chains and Silicone Chains as a Fluorine-Free Water Repellent

With environmental and health issues being raised, researchers have shifted their study from fluorinated to fluorine-free waterproof agents. However, most of the reported fluorine-free water repellents exhibit a significant drawback in their poor stability and durability of water repellency. In addition, the use of higher concentrations in these repellents results in the fabric becoming stiff, which negatively impacts the hand of the treated fabrics. To address these issues, dendrimer-like waterborne polyurethane prepolymers were initially synthesized using isophorone diisocyanate, polytetrahydrofuran, N-methyldiethanolamine, and trimethylolpropane as the primary materials. In this synthesis, sorbitan tristearate served as the dendrimer-like blocking agent, while single-ended bis-hydroxypropyl silicone oil was employed as functional monomers to enhance the hand and water repellency of the prepolymers. Then, dendrimer-like waterborne polyurethane was finished on the cotton fabric using a pad–dry–cure procedure. The test results showed that the water contact angle of dendrimer-like waterborne polyurethane film increased from 104.28° to 107.00° with the content of single-ended bis-hydroxypropyl silicone oil increasing, and the water contact angle of dendrimer-like waterborne polyurethane-finished fabrics reached 148.6° alone with a standard spray test rating of 90–95. In addition, the water contact angle of dendrimer-like waterborne polyurethane-finished fabrics was still greater than 140° even after five standard washes. The single-ended bis-hydroxypropyl silicone oil addition facilitated similar hand to the original fabric in dendrimer-like waterborne polyurethane-finished fabrics with high concentrations, surpassing market water repellents. This work is of great significance for improving the stability and durability of water repellency, and the hand of waterborne polyurethane fluorine-free water repellents in the textile industry.

Development of a multifunctional bio-based insulation material with corncob and silica aerogel

Bio-based insulation materials with superior comprehensive properties are crucial to building energy conservation. This study aims to develop a multifunctional bio-based insulation material that integrates good insulation, mechanical strength, and waterproofing. In this work, using corncob as the raw material, foamed geopolymer as the binder, silica aerogel and silicone oil as additives, a novel bio-based insulation material was prepared. Moreover, the effect of corncob size, silica aerogel content and silicone oil content on the microstructure, density, thermal conductivity, compressive strength, water absorption, moisture absorption and water contact angle properties were discussed. The results showed that, a desirable bio-based insulation material with a corncob size of 20 mesh, silica aerogel/geopolymer mass ratio (A/G) being 1.71 %, silica aerogel/ silicone oil mass ratio (A/O) being 0.2, is recommended, of which the thermal conductivity is 0.111 W/(m.K) with the compressive strength being 2.2 MPa, the density being 350 kg/m3, the water absorption being 7.1 %, the moisture absorption being 9.4 % and the water contact angle being 133°. With a simple preparation process, low cost and low energy consumption, this bio-based insulation material has good application prospects in buildings. Meanwhile, the preparation method of bio-based insulation materials proposed in this study provides new ideas for the development of multifunctional insulation materials in the future.

Study on sedimentation stability of silicone oil-based magnetorheological fluids with fumed silica as additive

In order to study the sedimentation stability of silicone oil-based magnetorheological fluids with fumed silica as additive, magnetorheological fluids with different mass fractions of fumed silica, particle sizes of carbonyl iron powder and viscosities of silicone oil were prepared. The sedimentation rate of magnetorheological fluids was calculated by observation method, and the zero-field viscosity of magnetorheological fluids was measured by viscometer. The results show that the sedimentation rate and viscosity of magnetorheological fluids increase gradually with the increase of the mass fraction of fumed silica. The mass fraction of fumed silica should not be constant for magnetorheological fluids, but should be determined according to the content of silicone oil in magnetorheological fluids. With the increase of average diameter of carbonyl iron powder, the sedimentation stability of magnetorheological fluids becomes worse. With the increase of viscosity of silicone oil, the sedimentation stability of magnetorheological fluids does not increase significantly. However, the high viscosity of silicone oil will result in wall hanging phenomenon, and increase the start-up difficulty of magnetorheological device. With 2.5 wt% of fumed silica for silicone oil, the magnetorheological fluids has good sedimentation stability and suitable zero-field viscosity.

Effect of Methyl Hydro-Silicone Oil Content and Aging Time on Compression Modulus and Breakdown Strength of Additional Liquid Silicone Rubber Gel.

The performance of silicone rubber gel elastomers is affected by the composition and structure of the crosslinker. In this work, a two-component addition liquid silicone rubber gel material was developed, and the effects of the contents of two methyl hydro-silicone oils on the compression modulus and breakdown strength of the silicone rubber gel insulating material, as well as the performance change after hot air aging at different times (24 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h), were studied. The results showed that the breakdown strength and compression modulus exhibited an upward trend with the increase in the hydrogen silicone oil content. The best performance was achieved in the silicone rubber gel with Si-H:Si-Vi = 1.4:1. Moreover, with the increase in aging time, the breakdown strength decreased and the compression modulus increased.

Effect of the cross-linking of polyorganosiloxane on highly thermally conductive silicone rubber's mechanical, dielectric, and thermally conductive properties and thermal reliability

With the rapid development of thermal management techniques, there is an urgent need for thermally conductive silicone rubber (TCSR) which has high softness, high electrical insulation, high thermal conductivity, and high reliability. Currently, the reliability problem has received little attention in the academic reports. Herein, the effect of the cross-linking of polyorganosiloxane on TCSR's mechanical, dielectric, and thermal properties and thermal reliability has been studied. It is found that the cross-linking has great impacts on the thermal reliability of mechanical and oil bleeding properties, and slight impacts on the thermal reliability of dielectric and thermally conductive properties. When the content of hydrogen-terminated silicone oil is 2–4 phr and the content of hydrogen-side silicone oil is 1.5–1.8 phr, the resultant TCSR has high properties, including high softness (Shore OO hardness 55−68), high compression ratio (20−40 % @ 20 psi), high dielectric strength (5.3−5.7 kV/mm), high thermal conductivity (4.3−4.8 W/mK), and high thermal reliability (less than 10 % variation for most properties after thermal aging). Possible mechanisms have been discussed.

Preparation and properties of organosilicon-polyurea composites

A series of organosilicon-polyurea composites were synthesized with hydroxy silicone oil (PDMS), coupling agent KH902, hexamethylene diisocyanate (HDI) and polyaspartate resin F420. The properties of the composites were characterized by tensile strength, adhesion, water absorption and thermogravimetric analysis. The effects of silicone modification conditions and silicone content on the properties of the composites were investigated. The results showed that the adhesion, water resistance and thermal stability of the composites were improved with the introduction of organosilicon. When the content of hydroxy silicone oil was 20%, the tensile strength of the composite was 37.614 Mpa, the elongation at break was 20.13%, the adhesion to cement mortar was 4.68 Mpa, and the water absorption was only 1.35%.

Innovative polishing stage in biogas upgrading: Siloxanes abatement in an anoxic two-phase partitioning biotrickling filter

The present work investigated for the first time the feasibility of the anoxic biodegradation of siloxanes (hexamethyldisiloxane, L2; octamethyltrisiloxane, L3; octamethylcyclotetrasiloxane, D4; and decamethylcyclopentasiloxane, D5) in a two-phase partitioning biotrickling filter (TP-BTF) using silicone oil as the organic phase. The influence of the silicone oil ratio and the inlet concentration of siloxanes were also evaluated. The highest removals were obtained for D4 (41–54%) and D5 (48–73%). Lower removals were recorded for L2 (12–15%) and L3 (22–38%) as a consequence of their higher volatility. The best performance was obtained at a silicone oil content of 45%. Doubling the inlet load enhanced the elimination capacity of the TP-BTF by 50%, although the removal efficiencies did not vary. A specialized bacteria consortium dominated by the genera Parvibaculum, Zarvaz inia, KCM-B-11, Arenimonas, Moraxellaceae and Luteimonas was related to anoxic siloxanes degradation.

Effect of Vinyl-Terminated Silicone Oil Chain Length and Reinforcing Agent on the Properties of Silicone Rubber

To solve the problems of low strength and high viscosity of room temperature vulcanized liquid silicone rubber, a series of terminated vinyl silicone oil were designed and synthesized, and low viscosity and high strength silicone rubber were prepared by the mechanical reinforcing agent. the results show that the molecular structure of the vinyl-terminated silicone oil has a significant effect on the mechanical properties and viscosity of the silicone rubber, and the best performance is found when the content of vinyl-terminated silicone oil is 0.16%. The low viscosity and high strength silicone rubber prepared from it was reinforced by vinyl MQ resin and fumed silica, which had a significant effect on improving the performance. Its tensile strength increased to 5.03 MPa, elongation at break to 338.90%, and tear strength to 7.15 kN/m compared to conventional silicone rubber, while the hardness increased to 43°. The viscosity is 34.9 Pa•s. The compression modulus is 7.48 MPa.

Mechanical properties of bulk Sylgard 184 and its extension with silicone oil

Due to its simple curing and very good mechanical properties, Sylgard 184 belongs to the most widely and frequently used silicones in many industrial applications such as microfluidics and microengineering. On top of that its mechanical properties are further controllable through the curing temperature, which may vary from ambient temperature up to 200 °C; the lower the curing temperature the lower the mechanical properties (Johnston et al. in J Micromech Microeng 24:7, 2014. 10.1088/0960-1317/24/3/035017). However, certain specialised application may require even a softer binder than the low curing temperature allows for. In this study we show that this softening can be achieved with the addition of silicone oil into the Sylgard 184 system. To this end a series of Sylgard 184 samples with varying silicone oil concentrations were prepared and tested (tensile test, rotational rheometer) in order to determine how curing temperature and silicone oil content affect mechanical properties. Curing reaction of the polymer system was found to observe 2nd order kinetics in all cases, regardless the oil concentration used. The results suggest that within the tested concentration range the silicone oil addition can be used to soften commercial silicone Sylgard 184.

Effect of intensity of orientational magnetic field on steady shear behavior of magnetorheological elastomers

As filled elastomers, magnetorheological elastomers (MREs) undergo changes in their shape and physical and mechanical properties in response to an external magnetic field. To investigate how applying an orientational magnetic field during fabrication influences the magnetomechanical properties of MREs, several types of samples with different matrix properties were prepared and examined in lap shear tests under a magnetic field. The results show that with increasing orientational magnetic field and silicone-oil content, (i) the chain arrangement of the magneto-sensitive particles in the matrix becomes more obvious and (ii) the magneto-induced shear modulus and the magnetorheological effect of the prepared materials increase. To elucidate qualitatively the magneto-induced performance of MREs cured in different external magnetic fields, a microphysical model is proposed based on an exponential distribution of the angle between the magnetic-field direction and the chains formed by the magnetic particles, thereby to reduce the error due to the assumption of a uniform distribution. The present results provide a theoretical basis for designing and preparing magneto-sensitive smart materials.

Slippery coatings with mechanical robustness and self-replenishing properties as potential application on magnesium alloys

Slippery liquid-infused surfaces (SLISs) have the same development potential and application prospects as superhydrophobic surfaces (SHSs) in the fields of corrosion resistance, anti-icing, anti-fouling and drag reduction. However, the durability of SLISs is still a challenge because of the migrating, evaporating, or leaking of the infused liquids. Herein, we proposed a durable polydimethylsiloxane/silicone oil (PDMS-oil) system with mechanical robustness and self-replenishing property. As a demonstration of potential application, the PDMS-oil coating was applied on the magnesium alloy for multi-functions. A layer of PDMS cross-linking network was first cured on the magnesium alloy surface, and then a certain amount of low viscosity dimethyl silicone oil was diffused into the PDMS layer to form the final SLIS coatings. It is found that 50 wt% of silicone oil content is more suitable for the PDMS-oil based slippery coating on Mg alloy, which can maintain a low ice shear strength of less than 30 kPa after 20 icing/deicing cycles and a lower sliding angle of about 30° after wear cycles (under a normal pressure of 10 kPa). Significantly, the proposed PDMS-oil based slippery coating possesses good corrosion resistance and self-replenishing ability, which can also withstand hot water, ice water, and corrosive solutions (i.e. acid and alkaline aqueous solutions). The Mg alloy with the PDMS-oil based slippery coating can remain intact in a 3.5 wt% NaCl aqueous solution even after 20 days at room temperature. It is believed that the Mg alloys with the proposed PDMS-oil based slippery coatings would have more potential applications even in severe environments.

WO3-based slippery coatings with long-term stability for efficient fog harvesting

Inspired by Nepenthes pitcher plants, slippery liquid-infused porous surfaces (SLIPSs) have attracted wide attention and exhibited remarkable liquid repellency, droplet motion control and antifouling properties. However, lubricant-impregnated surfaces have poor durability, leading to loss of control of the movements of droplets during applications. Herein, WO3-based slippery coatings with high stability were prepared by the spray method and photocatalytic reaction. Notably, on the basis of the hierarchical structures, the strong intermolecular forces between the polydimethylsiloxane brush and silicone oil led to the formation of a stable lubricant layer on the WO3-based slippery coating, which can suppress lubricant loss during water collection. After a series of stability tests, such as high-speed centrifugation, long-term storage, acidic solution and multiple heating/cooling cycles, the biomimetic slippery surface still displays excellent surface-slippery stability. Furthermore, the slippery surface exhibits superior water mist capture, water droplet expansion and harvested water removal abilities, leading to good water collection performance. The silicone oil content in the collected water was 28 mg/L, demonstrating that the loss of oil was lower during the water collection process. Even under harsh environments, including multiple heating/cooling cycles, long-term storage and high shear force, lubricant-impregnated coatings can also maintain good water collection efficiency. Therefore, these slippery coatings are promising for widespread application.

Do not flick or drop off-label use plastic syringes in handling therapeutic proteins before administration.

This study investigates the formation of subvisible particles formed by external stresses produced such as flicking and dropping syringes. Flow imaging was used to visualize and quantify microparticles from 1μm to over 25μm as a result of mishandling. Microparticles increased in the presence of silicone oil that was present in syringes. Thus, silicone oil in syringes may affect the activity of therapeutic proteins being injected. Present data showed detailed and differentiated morphologies of proteinaceous particles, silicone oil, air bubbles, and plastic debris in mishandled syringes. In some cases, the presence of bisphenol A in syringes was detected by FT-IR. Disposable plastic syringes were evaluated and showed differences in their content of silicone oil. Syringes that contain 0.45μm filters inside the needle cap as well as silicone oil-free syringes release proteinaceous subvisible particles after mechanical stress. These stress-generated particles can be delivered to patients, compromising patient care.

Mechanical properties of high-ductility cementitious composites with methyl silicone oil

Methyl silicone oil is used to precondition silica sand for the preparation of high-ductility cementitious composites. Its effect on their mechanical properties is investigated. Results indicate that the presence of methyl silicone oil significantly enhances the ductility (tensile strain capacity) of high-ductility cementitious composites while undermining their compressive and flexural strengths. The strain hardening behaviour, which is indicated by the slope of the linearised tensile stress–strain curve following the first cracking point, was found to be a maximum at 2% methyl silicone oil followed by a gradual decrease at a higher methyl silicone oil content. This behaviour can be explained by the interaction mechanism of methyl silicone oil on the matrix and fibre–matrix interface. Methyl silicone oil is found to improve the fibre distribution as a result of the oil presence on the fibre surface. Microscopic observation reveals that the fibre–matrix interface becomes porous through the presence of thin rod-like hydration products. This reduces the fibre bonding to the matrix that facilitates pullout but increases the post-pullout friction, which is beneficial in ductility improvement.

Facile One-Step Method to Fabricate a Slippery Lubricant-Infused Surface (LIS) with Self-Replenishment Properties for Anti-Icing Applications

In this work, a slippery lubricant-infused surface (LIS) was prepared by simple one-step mixing of polydimethylsiloxane (PDMS) resin and dimethyl silicone oil (PMX-200) directly. Silicone oil showed good compatibility with PDMS resin, and the added amount of silicone oil had no significant effect on the surface morphology of LIS. According to the results of surface observations, once the silicone oil film anchored on the LIS was removed, the silicone oil inside the PDMS polymer automatically diffused to the surface and formed a new silicone oil film again in a short time. Furthermore, with the increase of silicone oil content, the oil self-replenishment speed and amount of the LIS were enhanced, which also promoted a decrease of the surface water sliding angle and the improvement of the lubrication ability of the LIS. In the icing/deicing cycle tests, the slippery LIS still maintained very low ice adhesion strength after 24 cycles, showing excellent anti-icing performance.

Self-Designed Hydrophilicity-Related Geomaterials and Their Testing Utility in Simulation of Overlying Strata Instability

This paper mainly involved the testing of self-designed hydrophilicity-related geomaterials and application of overlying strata monitoring in a mining area in Northwest China. We employed the orthogonal testing technique to select the ingredient ratio of hydrophilicity-related geomaterials and optimized the mechanical properties of materials, such as density, elastic modulus, Poisson ratio, compressive strength, tensile strength, and water absorption rate on the basis of regression analysis. It can be seen that the proportion of the mixture clearly determines the mechanical properties of similar materials. Among them, the content of silicone oil and the cement-Vaseline ratio have the most obvious effects on the mechanical properties of the material. By using the hydrophilicity-related geomaterials with ingredient optimization, we built a physical model to simulate the failure progress of the workface in one of the coal mines in Northwest China. It was shown that three remarkable characteristic parts, including collapse zone, fissure zone, and layer-separating space, appear in the overlying strata. Furthermore, the fractured zone above the separating band is just located under the main aquifer. Finally, compared with in-field data, it was verified that the height of the collapse zone and water-guiding fissure zone measured at three boreholes are in good agreement with the experiment. Thus, the failure mode of overburden and the vertical stress and displacement changes are consistent with the actual engineering. Self-developed hydrophilicity-related geomaterials can be applied to laboratory physical simulation experiments of overlying strata. It provides the basis for future research on large-scale physical water-containing similar simulation experiments.

Evaluating the ability of energy dispersive X-ray analysis to monitor binding oil content of carbon paste electrodes exposed to biofouling agents

Physiological conditions can alter the performance of electrochemical sensors through complex interactions arising at the tissue matrix and electrode interface. Understanding this relationship is a prerequisite to the eventual deployment of these sensors in vivo. Herein, we investigate the ability of energy dispersive X-ray (EDX) analysis to monitor silicone oil levels within carbon paste electrodes (CPE). We correlate these findings with scanning electron microscopy (SEM) images and cyclic voltammetry (CV) data. EDX analysis reported significant variations in silicone oil content when the CPE was immersed in protein (bovine serum albumin (BSA)), lipid (phosphatidylethanolamine (PEA)), surfactant (Triton®X (TX)) and brain tissue over a 28-day period. Moreover, the greatest effect occurs within the first 24h of exposure. Protein adsorption appears to hinder the X-rays emitted during SEM imaging resulting in reduced silicone oil measured by EDX. SEM images and voltammetric profiles support this finding. Brain tissue homogenate appears to reduce silicone levels at a slower rate than PEA and TX which corroborates voltammetric data. Notwithstanding this, the surface morphology determined by SEM imaging suggests comparable surface alterations for the three treatments over the 28days. Finally, we report the impact that continuously cycling CPEs in protein and lipid has on the silicone oil content. There was a significant improvement recorded over a 3.5h period when compared to EDX analysis performed on CPEs stored in the solutions for the same period. Collectively, the data provided within support the utility of EDX analysis as a valid and simple surface analytical technique that can be employed to follow the removal of silicone oil from CPEs.

Influence of Hydroxyl Silicone Oil on Mechanical and Electrical Properties of Silicone Rubber-based ceramizable composites

By introducing hydroxyl silicone oil into silicone rubber-based ceramizable composites(CSR), the structural problems of nano-silica in CSR are inhibited. The influence of hydroxy silicone oil content on the mechanical and electrical properties of CSR was investigated. And the chemical, physical and mathematical models were established to explain the influence mechanism. The results show that the hydroxy silicone oil inhibits the structural problem and improves the dispersion of nano-silica in CSR, which are contribute to the increases of tensile strength and elongation at break of CSR. And the volume resistivity decreases as to interface barrier decreasing, the loss factor decreases as to the decay of space charge polarization, the ac electric strength increases with mean free path of free charge decreasing. However, the relative permittivity of CSR is not sensitive to hydroxy silicone oil content.

Quantification of Silicone Oil and Its Degradation Products in Aqueous Pharmaceutical Formulations by 1H-NMR Spectroscopy

During the past years, there has been an increasing focus on the presence of silicone oil as a contaminant in pharmaceutical formulations kept in prefilled syringes (PFSs). As the PFSs are coated on the inner wall with silicone oil (polydimethylsiloxane), there is a potential risk that the oil can migrate from the inner surface of the primary packing material into the aqueous solution. Several studies have demonstrated that presence of silicone oil as droplets in a high-concentrated protein formulation can cause protein aggregation. Hence, because the use of silicone-coated primary packing material for protein formulations are increasing, the call for an easy and quantitative method for determination of silicone oil and its degradation products in pharmaceutical formulations is therefore needed. Several analytical techniques have in the past been developed with the aim of detecting the presence of silicone oil and degradation products hereof. Most of these methods require hydrolyzation, derivatization, and extraction steps followed by, for example, gas chromatography-mass spectrometry analysis. Applying these methods can cause a loss in detection or an overestimation of the hydrolytic degradation products of silicone oil, that is, trimethylsilanol and dimethylsilanediol. The 2 silanols are highly hydrophilic and prefers the aqueous environment. Analysis of an aqueous formulation obtained from a PFS by 1H-NMR spectroscopy provides data about the content and levels of silicone oil and the 2 silanols even in levels below 10 ppm. The 1H-NMR method offers an easy and direct, quantitative measurement of samples intended for clinical use and samples kept at elevated temperature for a prolonged time (i.e., stability studies). The result of the study presented here showed dimethylsilanediol to be the main silicone compound present in the aqueous formulation when kept in baked-on PFSs. The degradation product dimethylsilanediol, in full accordance with expected hydrolytic degradation of silicone oil, increased during storage and with elevated temperature. In addition, the method can be applied to aqueous samples where polydimethylsiloxane has been added as, for example, the major constituent of antifoam.

Multi-Objective Optimization of Acoustical Properties of PU-Bamboo-Chips Foam Composites

Abstract In this study, an effective optimization approach was proposed to improve acoustical behaviors of PU foams. The important parameters of PU foams: content of water, silicone oil and catalyst A1 were chosen and their effects on sound absorption coefficient and transmission loss of PU foams were studied by using Taguchi methods. In addition, bamboo chips were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Four controlled factors: the content of water, silicone oil, catalyst A1 and bamboo chips with three levels for each factor were chosen and Taguchi method based on orthogonal array L9(34) was employed to conduct the experiments. Based on the results of Taguchi’s orthogonal array L9(34), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU-bamboo-chips foam composites.