Polymer modified nanosilica as a sorbent for medical applications

Носач, Л. В.; Воронин, Е. Ф.; Pakhlov, E.M.; Guzenko, N.V.; Gun'ko, V.М.

doi:10.1016/b978-0-12-815875-3.00007-2

Cited by 5 publications

(13 citation statements)

References 11 publications

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“…Next to providing a visual impression of the materials under investigation, these results denote the formation of “core(NP)–shell(polymer)”-like entities, especially for the low w polymer (≤50 wt %), as the “nano-particulate” morphology of initial silica (Figure a) can be visually observed also in the PNCs (Figure b–e). As expected, the size of the core–shell entities in the PNCs is larger than that of the initial particles . This has been observed before in similar silica/PDMS ,,, and in titania (TiO 2 )/PDMS PNCs, whereas the existence of the polymeric shell has been further confirmed by different techniques, such as thermogravimetric analysis .…”

Section: Resultssupporting

confidence: 79%

“…(b) RAF dependence of T g for the PNCs studied here [same symbols as in (a)]; included are the data for the neat polymers (vertical line in RAF = 0 position). The inset schemes in (b) are used for explaining the effects of RAF in terms of the expected polymer–NP distributions , (details in the main text). The dashed-dotted lines were added to guide the eye.…”

Section: Resultsmentioning

confidence: 99%

“…This method offers the benefit for increased coverage of the particles by the polymer as compared to more conventional techniques, such as impregnation of particles by a polymer solution. 56,57 In addition, we should report another severe difference between the two types of PNCs. This difference originates from the nature and strength of polymer−silica interactions.…”

Section: Methodsmentioning

confidence: 97%

“…The amount of the polymer in the PNCs varies between 5 and 80 wt %. For this study, a relatively new preparation method for core/shelltype PNCs is employed, namely, the “ gas-phase mechano-sorption modification” , (details in the Supporting Information). This method offers the benefit for increased coverage of the particles by the polymer as compared to more conventional techniques, such as impregnation of particles by a polymer solution. , …”

Section: Methodsmentioning

confidence: 99%

“…Upon heating of the silica/PEHS samples, a significant fraction of the Si−H groups of PEHS interacts with the silica silanols, Si−OH, according to the following scheme, 58,59 more details are given in the Supporting Information and in previous work. 57 The process just described is called chemisorption. 57−59 Results by IR (Section S2 in the Supporting Information) 49,64 provide support for the stronger interaction between silica and PEHS than PDMS, by recording stronger suppression of the silanol peaks at already 5% polymer loading (36 and 67% suppression for PDMS and PEHS, respectively).…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Glass Transition and Molecular Dynamics in Core–Shell-Type Nanocomposites Based on Fumed Silica and Polysiloxanes: Comparison between Poly(dimethylsiloxane) and Poly(ethylhydrosiloxane)

et al. 2019

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The interfacial polymer in nanocomposites (PNCs) is widely believed to exhibit modified dynamics and structure, which are considered responsible for the improved PNC properties. Owing to its high resolving power, broadband dielectric spectroscopy (BDS) is one among the most suitable tools for studying polymer dynamics. Here, BDS combined with differential scanning calorimetry (DSC), microscopy, infrared spectroscopy, and thermally stimulated depolarization currents (TSDC) are employed to study low-molecular weight polydimethylsiloxane (PDMS) and a slightly modified siloxane, polyethylhydrosiloxane (PEHS), in bulk and in the form of silica− polymer "core−shell"-type PNCs. The dielectric/calorimetric mapping for the systems based on PEHS is demonstrated for the first time. Bulk-like dynamics (α relaxation, glass transition) is recorded faster and less cooperative in the PNCs, in agreement between the techniques, most probably due to spatial confinement between the neighboring nanoparticles. The constraints arising from the particle−polymer interactions resulted in the formation of an interfacial polymer fraction, being rigid and similar in amount for the two polymers in DSC, whereas a part of this latter amount (e.g. tails and loops) exhibits retarded dynamics in BDS and TSDC. The interfacial polymer dynamics is recorded individually via the α int relaxation next to α in the PNCs. For PEHS, α int is quite weak showing a non cooperative character (sparsely distributed short tails), while it is strong exhibiting low cooperativity for PDMS (loops and tails). Because both polymers consist of small chains and exhibit similar flexibility, it is concluded that the differences in α int arise from the type and the extent of interfacial interactions, for example, the additional covalent bonding in silica/PEHS leading to the formation of many immobile trains. Finally, the absolute differences in the relaxation times between the α and α int were found similar for PEHS and PDMS, which, interestingly, suggests a "coupling" between the polymer structure and its dynamics in the bulk (unconstrained) and interfacial (constrained) state.

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Section: Resultssupporting

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Glass Transition and Molecular Dynamics in Core–Shell-Type Nanocomposites Based on Fumed Silica and Polysiloxanes: Comparison between Poly(dimethylsiloxane) and Poly(ethylhydrosiloxane)

et al. 2019

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In situ synthesis of AgI on the nanosilica surface for potential application as a cloud seeding material

Nosach,

Bodnar Yankovych,

Skwarek

et al. 2024

ChemPhysChem

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A series of nanosilica/AgI composites was synthesized by in situ reactions between silver nitrate and ammonium iodide deposited on the nanosilica surface using the gas‐phase solvate‐stimulated mechanosorption modification (GSSMSM) under both dry and wet conditions. The characterization of the synthesized materials was performed by X‐ray diffraction (XRD), SEM/EDX (Scanning Electron Microscopy‐Energy Dispersive X‐ray), thermogravimetric (TGA) and gas sorption methods. As a result of the mechanosorption modification of nanosilica, the bulk density of the samples synthesized in the dry and wet medium increases from 45 g/l for initial nanosilica to 249 g/l and 296 g/l for the modified samples, respectively. The specific surface area of the composites decreased in compared to the nanosilica precursor. The SEM data showed a denser aggregate structure of the nanocomposites compared to the initial nanosilica. The XRD, SEM/EDX and TEM/EDX data indicated the formation of AgI clusters. The AgI particle size was in the range of 6‐45 nm. The ice‐forming activity of the AgI‐containing samples was examined as well. The sample with a smaller size of silver iodide on the surface exhibited superior ice‐forming properties, and considering the quantity of utilized AgI, the prepared samples hold promise for application in this field.

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Nanostructure and thermal characteristics of silica/human serum albumin systems based on a modified nanosilica entero-vulnerosorbent

Chrzanowska,

Nosach,

Derylo-Marczewska

2024

Phys. Chem. Chem. Phys.

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Polymer modified nanosilica as a sorbent for medical applications

Cited by 5 publications

References 11 publications

Glass Transition and Molecular Dynamics in Core–Shell-Type Nanocomposites Based on Fumed Silica and Polysiloxanes: Comparison between Poly(dimethylsiloxane) and Poly(ethylhydrosiloxane)

Glass Transition and Molecular Dynamics in Core–Shell-Type Nanocomposites Based on Fumed Silica and Polysiloxanes: Comparison between Poly(dimethylsiloxane) and Poly(ethylhydrosiloxane)

In situ synthesis of AgI on the nanosilica surface for potential application as a cloud seeding material

Nanostructure and thermal characteristics of silica/human serum albumin systems based on a modified nanosilica entero-vulnerosorbent

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