Polydimethylsiloxane Shell Research Articles

Pushing Patterning Limits of Drop‐On‐Demand Inkjet Printing with Cspbbr3/PDMS Nanoparticles

AbstractPatterning is crucial for advancing perovskite materials into color conversion micro‐display applications, but achieving inkjet‐printed patterns with high performance and precision remains challenging. Here, novel CsPbBr3/PDMS nanoparticles as a promising candidate is proposed for achieving precise and perfect inkjet printing patterns. The as‐prepared nanoparticles ensure exceeding brightness, exceptional stability, uniform fluorescence emission, and high resolution reaching the highest performance of drop‐on‐demand inkjet printing. Specifically, the performance and stability of CsPbBr3/PDMS nanoparticles are enhanced through a two‐step optimization involving dodecyl benzene sulfonic acid (DBSA) ligand modification and polydimethylsiloxane (PDMS) in situ coating, resulting in the highest photoluminescence quantum yield (PLQY) of 92% among CsPbBr3/polymer core‐shell composites so far. The branched structure of DBSA and the PDMS shell provide steric hindrance and effectively prevent agglomeration during storage or patterning. The viscous PDMS coating inhibits the coffee ring effect, not only leading to excellent near‐unity uniform emission but also promoting the formation of smaller and more elaborate droplets, increasing the printing resolution by up to surprisingly 300%. Importantly, the impeccably displayed, high‐resolution patterns formed by versatile CsPbBr3/PDMS nanoparticles have demonstrated significant potential for high pixel density Micro‐LED displays, enabling efficient and stable color conversion.

Silicone Migration from Intact Saline Breast Implants

Summary: Breast augmentation is a widely performed surgical procedure worldwide, predominantly using silicone gel-filled implants. Concerns have primarily revolved around ruptures and the potential health risks associated with leaked silicone from silicone gel-filled implants. Cases of silicone migration from the shell of saline breast implants remain scarce. This case report introduces a unique case of a 66-year-old patient with silicone migration from intact saline breast implants. The patient presented with a range of symptoms consistent with breast implant illness. Radiological findings suggested the presence of silicone in the axillary lymph nodes, despite the integrity of the implants, thereby confirming silicone migration. Histopathological evaluation revealed a foreign body reaction and the presence of silicone in the axillary lymph nodes. Given the saline filling, the source is likely the polydimethylsiloxane shell. The rarity of documented silicone migration from intact saline breast implants, especially in patients with breast implant illness, underscores the need for more research into the health implications of leaked silicone particles from breast implants.

Fire-resistant and hydrophobic paper based on Si3N4@PDMS core-shell nanowires with 3D interlocking structure

Paper with simultaneous fire-resistance and hydrophobicity have greatly potential applications in the fields of packing, storage and delivering information, which attracts increasing attention recently. Different from the traditional cellulose-based paper which is extremely easily damaged by water and fire, a new type of highly flexible, fire-resistant and hydrophobic paper based on Si3N4 nanowires and polydimethylsiloxane (PDMS) is reported. Specially, the Si3N4@PDMS core-shell nanowires with 3D interlocking structure are designed, in which the Si3N4 nanowires act as the inorganic fire-resistant frameworks and the PDMS shell with low surface energy provides the hydrophobic surface. The Si3N4@PDMS core-shell nanowires are intertwined and interlaced to form a highly flexible Si3N4@PDMS paper. The tensile strength of Si3N4@PDMS paper is 6.19 MPa, indicating the good mechanical property. The obtained Si3N4@PDMS paper has the characteristics of writability, fire-resistance and hydrophobicity. The high thermal stability of Si3N4 nanowires makes Si3N4@PDMS paper exhibit excellent fire resistance. No obvious change is observed for the commercial paper with Si3N4@PDMS paper as the fire-shielding layer after heating for 30 min. In addition, the contact angles of water droplets are all greater than 110° over the surfaces of Si3N4@PDMS paper after mechanical damages, chemical corrosions and thermal treatments. Si3N4@PDMS paper can be used in oil/water separation and oil collection. More importantly, Si3N4@PDMS paper can be used for writing without being damaged by fire or water. The present work may inspire the development and application of functional paper and is expected to become a breakthrough in the traditional paper industry.

Low-Diffusion Fricke Gel Dosimeters with Core-Shell Structure Based on Spatial Confinement.

The diffusion of ferric ions is an important challenge to limit the application of Fricke gel dosimeters in accurate three-dimensional dose verification of modern radiotherapy. In this work, low-diffusion Fricke gel dosimeters, with a core-shell structure based on spatial confinement, were constructed by utilizing microdroplet ultrarapid freezing and coating technology. Polydimethylsiloxane (PDMS), with its excellent hydrophobicity, was coated on the surface of the pellets. The concentration gradient of the ferric ion was realized through shielding half of a Co-60 photon beam field size, and ion diffusion was measured by both ultraviolet-visible spectrophotometry and magnetic resonance imaging. No diffusion occurred between the core-shell pellets, even at 96 h after irradiation, and the diffusion length at the irradiation boundary was limited to the diameter (2–3 mm) of the pellets. Furthermore, Monte Carlo calculations were conducted to study dosimetric properties of the core-shell dosimeter, which indicated that a PDMS shell hardly affected the performance of the dosimeter.

Microbial Nanoculture as an Artificial Microniche.

Microbes self-organize in microcolonies while transitioning to a sessile form within a protective biofilm matrix. To enable the detailed study of microbial dynamics within these microcolonies, new sessile culture systems are needed that sequester cells and mimic their complex growth conditions and interactions. We present a new nanoliter-scale sessile culture system that is easily implemented via microfluidics-enabled fabrication. Hundreds of thousands of these nanocultures can be easily generated and imaged using conventional or confocal microscopy. Each nanoculture begins as a several nanoliter droplet of suspended cells, encapsulated by a polydimethylsiloxane (PDMS) membrane. The PDMS shell provides long-lasting mechanical support, enabling long term study, and is selectively permeable to small molecules including antibiotics, signaling molecules and functional fluorescent probes. Thus, as microcolonies mature within the nanocultures, they can be stressed or interrogated using selected probes to characterize cell physiological properties, antibiotic susceptibilities, and antagonistic interactions. We demonstrate this platform by investigating broad ranges of microcolony dynamics, including direct and indirect bacterial-fungal interactions. This versatile new tool has broad potential for addressing biological questions associated with drug resistance, chronic infections, microbiome dynamics, and antibiotic discovery.

High-performance, recyclable and superhydrophobic oil absorbents consisting of cotton with a polydimethylsiloxane shell

This study presents the results related to the preparation and characterization of cotton-based oil absorbents dry-coated with polydimethylsiloxane (PDMS) that can absorb 30–65 times their weight in oil. PDMS is coated onto these absorbents using chemical vapour deposition without the use of chemicals other than PDMS. The absorbed oils can be separated from the absorbents by centrifugal force indicating that the absorbents are recyclable. The absorbents are also hydrophobic and have a water contact angle exceeding 150°. This hydrophobicity allows perfectly selective removal of oil from an oil/water mixture. We also suggest a funnel structure for effective filtering of oil.

Magnetic, Fluorescent, and Copolymeric Silicone Microspheres.

Silicone microspheres are exceedingly difficult to make. Here, polydimethylsiloxane microspheres (≈1 μm diameter) are synthesized using ultrasonic spray pyrolysis, the first demonstration of a scalable synthetic procedure for crosslinked silicone microspheres. This continuous, aerosol process is also used to directly produce fluorescent, magnetic, and copolymeric derivatives; the potential biomedical applications of these microspheres are explored.

Microfluidic fabrication and micromechanics of permeable and impermeable elastomeric microbubbles.

We use droplet microfluidics to produce monodisperse elastomeric microbubbles consisting of gas encapsulated in a polydimethylsiloxane shell. These microbubbles withstand large, repeated deformations without rupture. We perform μN-scale compression tests on individual microbubbles and find their response to be highly dependent on the shell permeability; during deformation, the pressure inside impermeable microbubbles increases, resulting in an exponential increase in the applied force. Finite element models are used to interpret and extend these experimental results enabling the design and development of deformable microbubbles with a predictable mechanical response. Such microbubbles can be designed to repeatedly transit through the narrow constrictions found in a porous medium functioning as probes of the local pressure.

Microencapsulation of Active Ingredients Using PDMS as Shell Material

We report an efficient and adaptable method for the microencapsulation of active ingredients by a polydimethylsiloxane (PDMS) shell material. The core–shell microcapsules were obtained by phase separation between the core component and the PDMS shell components after repartitioning of the common solvent THF between the PDMS/core material phase and the water phase. For the shell components, two commercially available functional PDMS polymers containing thiol and vinyl side groups were used. Photo-cross-linking in the presence of 2,2-dimethoxy-2-phenylacetophenone (DMPA) by thiol–ene radical addition was used to form a PDMS-thioether cross-linked shell. Variation of the PDMS component thiol to ene ratio resulted in different functionalities on the microcapsules surface and in the bulk, which was analyzed by attenuated total-reflection infrared spectroscopy (ATR-IR) and high-resolution magic-angle NMR-spectroscopy (HR-MAS NMR). Organically modified silica particles were mixed into the PDMS shell, resulting in better mechanical properties of the shell and control over the shell permeability, as measured on the one hand by tensile testing of representative PDMS bulk samples of identical composition as the actual shell material and on the other hand by leaching experiments of the core compounds, such as a tetrathiol and the UV-absorber octocrylene, followed by UV–vis.

Nanoscale Rings from Silicon-Containing Triblock Terpolymers

Nanoscopic ring arrays of various materials show promise for both technological applications and fundamental studies. In this work we report the preparation of sub-50 nm diameter ring arrays from metallic thin films using a block polymer lithographic pattern transfer approach. We prepared a triblock terpolymer that adopts a core-shell cylindrical morphology where the shell is an oxidizable polydimethylsiloxane block. Solvent annealed thin films of this terpolymer produce cylindrical features oriented perpendicular to the substrate surface. The polydimethylsiloxane shell is then converted into SiOx rings by an oxygen reactive ion etch. The resultant hard mask pattern is then transferred into Au, Ni80Fe20, and Ni80Cr20 thin films via Ar ion beam milling, demonstrating the generality of the approach.

Preparation of the stable core–shell latex particles containing organic-siloxane in the shell

In this study, the latex particles with a polyacrylate core and a polydimethylsiloxane shell via 3-(methacryloxypropyl)-trimethoxysilane as the space arm to link the core and shell have been prepared by semi continuous seeded emulsion polymerization. And several key polymerization reaction conditions such as the emulsifier concentration, 3-(methacryloxypropyl)-trimethoxysilane dosages, feeding sequence and the acrylates/siloxanes ratio were detailedly discussed. Then, the optimal condition to prepare stable core/shell particles was selected and a proper preparation process has been established. The as-synthesized particles were characterized by TEM and XPS. The clear core/shell structure of the particles could be observed through analysis TEM. In addition, the results of XPS analyses manifested that siloxanes had been grafted on the surface of the polyacrylate particles and they distributed on the outmost layer of the particles. Finally, the surface hydrophobicity of the film formed by latex particles was investigated by the water absorption ratio measurement. The results indicated the developed latex particle provided with a fair water-repellency property.