Reactive and Functional Silicones for Special Applications

Racleş, Carmen; Dascălu, Mihaela; Bele, Adrian; Cazacu, Maria

doi:10.1007/978-3-030-43403-8_11

Cited by 9 publications

(8 citation statements)

References 285 publications

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“…20 mN/m, at low concentrations. In terms of morphology, the preferred type of aggregates are vesicles [ 104 , 105 , 106 , 107 ], which opens interesting possibilities for drug delivery systems and cosmetic formulations. Aggregates of siloxane surfactants containing glucose [ 108 ], amino-pyridine [ 109 ] or tromethamol [ 106 ] hydrophilic groups are exemplified in Figure 6 A, while in Figure 6 B some of the applications proposed for siloxane surfactants are illustrated.…”

Section: Siloxane-siloxane and Siloxane-organic Copolymersmentioning

confidence: 99%

“…These ordered crosslinked materials combine the order and mobility of the LC phase with rubber-like elasticity. Some of their characteristics and applications have recently been reviewed [ 104 , 105 , 106 , 107 , 113 ]. Polarized light optical microscopy images of various types of siloxane-containing LCs are exemplified in Figure 8 , for a low molecular compound, an H-bond supramolecular polymer and an oligomeric surfactant [ 124 ].…”

Section: Siloxane-siloxane and Siloxane-organic Copolymersmentioning

confidence: 99%

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From Amorphous Silicones to Si-Containing Highly Ordered Polymers: Some Romanian Contributions in the Field

Cazacu¹,

Racleş²,

Zaltariov³

et al. 2021

Polymers

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Polydimethylsiloxane (PDMS), in spite of its well-defined helical structure, is an amorphous fluid even at extremely high molecular weights. The cause of this behavior is the high flexibility of the siloxane backbone and the lack of intermolecular interactions attributed to the presence of methyl groups. These make PDMS incompatible with almost any organic or inorganic component leading to phase separation in siloxane-siloxane copolymers containing blocks with polar organic groups and in siloxane-organic copolymers, where dimethylsiloxane segments co-exist with organic ones. Self-assembly at the micro- or nanometric scale is common in certain mixed structures, including micelles, vesicles, et cetera, manifesting reversibly in response to an external stimulus. Polymers with a very high degree of ordering in the form of high-quality crystals were obtained when siloxane/silane segments co-exist with coordinated metal blocks in the polymer chain. While in the case of coordination of secondary building units (SBUs) with siloxane ligands 1D chains are formed; when coordination is achieved in the presence of a mixture of ligands, siloxane and organic, 2D structures are formed in most cases. The Romanian research group’s results regarding these aspects are reviewed: from the synthesis of classic, amorphous silicone products, to their adaptation for use in emerging fields and to new self-assembled or highly ordered structures with properties that create perspectives for the use of silicones in hitherto unexpected areas.

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Section: Siloxane-siloxane and Siloxane-organic Copolymersmentioning

confidence: 99%

Section: Siloxane-siloxane and Siloxane-organic Copolymersmentioning

confidence: 99%

From Amorphous Silicones to Si-Containing Highly Ordered Polymers: Some Romanian Contributions in the Field

Cazacu¹,

Racleş²,

Zaltariov³

et al. 2021

Polymers

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“…Besides, Au-NPs have been used in biological and chemical sensing and diagnosis [20][21][22]. Similarly, the application of iron nanoparticles Fe-NPs has been extended to various surface treatments and biomedical applications due to their superparamagnetic properties and compatibility with the biological system, as well as their high safety profile [23]. Alternatively, the semiconductor material selenium has been introduced in the biomedical field as an essential trace mineral that might prevent cellular damage, maintain the thyroid gland, help proper functioning of the immune system, and provide antimicrobial and anti-carcinogenic activity [24,25].…”

Section: Introductionmentioning

confidence: 99%

Green Synthesis of Gold, Iron and Selenium Nanoparticles Using Phytoconstituents: Preliminary Evaluation of Antioxidant and Biocompatibility Potential

et al. 2022

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This study aimed at fabricating gold (Au), iron (Fe) and selenium (Se) nanoparticles (NPs) using various natural plant extracts from the Fertile Crescent area and evaluating their potential application as antioxidant and biocompatible agents to be used in the pharmaceutical field, especially in drug delivery. The Au-NPs were synthesized using Ephedra alata and Pistacia lentiscus extracts, whereas the Fe-NPs and Se-NPs were synthesized using peel, fruit and seed extracts of Punica granatum. The phytofabricated NPs were characterized by the UV-visible spectroscopy, scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and energy-dispersive X-ray (EDS) spectroscopy. Scanning electron microscope technique showed that the synthesized NPs surface was spherical, and the particle size analysis confirmed a particle size of 50 nm. The crystalline nature of the NPs was confirmed by the XRD analysis. All synthesized NPs were found to be biocompatible in the fibroblast and human erythroleukemic cell lines. Se-NPs showed a dose-dependent antitumor activity as evidenced from the experimental results with breast cancer (MCF-7) cells. A dose-dependent, free-radical scavenging effect of the Au-NPs and Se-NPs was observed in the DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay, with the highest effect recorded for Au-NPs.

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“…A very particular case is that of siloxane surfactants. These contain dimethylsiloxane units as the hydrophobic part and have several characteristics that make them unique and valuable compounds [ 23 ]. For example, they are able to considerably reduce the surface tension of water and organic media, present very low critical micelle concentration, have high ability of spreading and wetting, and tend to form vesicles in aqueous solution [ 23 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

“…These contain dimethylsiloxane units as the hydrophobic part and have several characteristics that make them unique and valuable compounds [ 23 ]. For example, they are able to considerably reduce the surface tension of water and organic media, present very low critical micelle concentration, have high ability of spreading and wetting, and tend to form vesicles in aqueous solution [ 23 , 24 ]. Besides the most commonly employed class, which are the polyether–siloxane surfactants of various design, a significant number of newer and less investigated surface-active silicones has been reported, wherein the hydrophilic groups can be nonionic (e.g., carbohydrates), ionic, or zwitterionic, and attached in terminal, pendant, or gemini architectures [ 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

Emulsion Gels as Precursors for Porous Silicones and All-Polymer Composites—A Proof of Concept Based on Siloxane Stabilizers

Racleş¹,

Bele²,

Vasiliu³

et al. 2022

Gels

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In spite of its versatility, the emulsion templating method is rather uncommon for the preparation of porous silicones. In this contribution, two siloxane-containing stabilizers, designed to be soluble in polar (water) and non-polar (toluene) solvents, respectively, were used in low concentrations to produce stable emulsions, wherein polysiloxane gels were obtained by UV-photoinitiated thiol-ene click cross-linking. The stabilizers exhibited negative interfacial tension, as measured by Wilhelmy plate tensiometry. The emulsion gels evolved into porous silicones (xerogels), with tunable morphology and properties. According to TEM and SEM investigations, the emulsion template was preserved in the final materials. Several parameters (e.g., the structure of the polysiloxane precursors, composition of the emulsion gels, nature of the continuous phase, cross-linking conditions, or additives) can be varied in order to obtain porous elastic materials with desired properties, such as Janus membranes, absorbent monoliths, all-polymer porous composites, or silicone-swollen gels. The feasibility of these types of materials was tested, and exemplary porous silicones were briefly characterized by contact angle measurements, mechanical testing, and absorption tests. The proposed method is simple, fast, and economic, uses very little amounts of stabilizers, and can be adjusted as a green technique. In this contribution, all the silicon-based materials with a convenient design were prepared in house.

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Reactive and Functional Silicones for Special Applications

Cited by 9 publications

References 285 publications

From Amorphous Silicones to Si-Containing Highly Ordered Polymers: Some Romanian Contributions in the Field

From Amorphous Silicones to Si-Containing Highly Ordered Polymers: Some Romanian Contributions in the Field

Green Synthesis of Gold, Iron and Selenium Nanoparticles Using Phytoconstituents: Preliminary Evaluation of Antioxidant and Biocompatibility Potential

Emulsion Gels as Precursors for Porous Silicones and All-Polymer Composites—A Proof of Concept Based on Siloxane Stabilizers

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