Evolution of Mesopores in Monolithic Macroporous Ethylene-Bridged Polysilsesquioxane Gels Incorporated with Nonionic Surfactant

Mushiake, Atsushi; Kanamori, Kazuyoshi; Nakanishi, Koji

doi:10.1155/2012/460835

Cited by 7 publications

(2 citation statements)

References 12 publications

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“…The shape change of the mesopores suggested from Fig. 2(C) can be explained by the rearrangement within the macropore skeletons 39) composed of the colloids rather loosely interconnected due to the presence of hydrogen-bonding surfactant. When both the amount of surfactant and water were increased, the mesopore size (21 to 59 nm) and mesopore volume (0.45 to 0.57 cm 3 g ¹1 ) were further increased due to the synergic effects from the inhibition of phase separation by F127 and the more incorporation of solvent in the gel-rich phase [Figs.…”

Section: Results and Discussion 31 Effect Of Starting Composition Onmentioning

confidence: 88%

Synthesis of hierarchically porous polymethylsilsesquioxane monoliths with controlled mesopores for HPLC separation

Zhu

Morimoto

Shimizu

et al. 2015

J. Ceram. Soc. Japan

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Solgel synthesis of macroporous polymethylsilsesquioxane (PMSQ) monoliths has been successful over the past decade, and applications to separation media have been investigated. However, the control of mesopores to tailor hierarchical porosity, which is promising for improvement of the separation efficiency, remains challenging. In particular, an independent control of mesoand macropores has not been achieved in PMSQ. Herein we present a method to synthesize PMSQ monoliths with well-defined macropores and controlled mesostructure (pore size ranging from 10 to 60 nm, total pore volume from 0.2 to 0.6 cm 3 g ¹1 ) via solgel accompanied by phase separation. Different Pluronic-type nonionic surfactants were used to control phase separation of the hydrophobic PMSQ network in aqueous media. Due to different packing density of the colloidal PMSQ constituents in the continuous skeletons in the micrometer-scale (termed as macropore skeletons) and their rearrangements through the hydrothermal post-treatment under basic conditions, mesopore characteristics have been successfully controlled independently of the preformed macropore structure. Separation columns for high-performance liquid chromatography (HPLC) have been fabricated using the PMSQ monoliths, and acceptable separation performances in both the reversed-phase and normal-phase modes have been demonstrated due to the presence of both hydrophilic silanol groups and hydrophobic methyl groups.

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Section: Results and Discussion 31 Effect Of Starting Composition Onmentioning

confidence: 88%

Synthesis of hierarchically porous polymethylsilsesquioxane monoliths with controlled mesopores for HPLC separation

Zhu

Morimoto

Shimizu

et al. 2015

J. Ceram. Soc. Japan

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“…This can be accomplished by incorporating microporosity through crystallinity or solvent templating of the sol-gel structure, mesoporosity through surfactant or polymer templating, spinodal phase separation (Mushiake et al 2012;Guo et al 2015), and macroporosity through colloidal templates (Jun et al 2005). For example, sol-gel polymerization of 1,2bistriethoxysilylethane in the presence of P-123 or F127 block copolymers as surfactant templates and urea to induce spinodal phase separation, mesoporosity and macroporosity can be created in the same material (Mushiake et al 2012). In some of these systems, there appears to be additional microporosity within the walls of the mesostructures (Brandhuber et al 2006).…”

Section: Hierarchical Materialsmentioning

confidence: 99%

Mesoporous Polysilsesquioxanes: Preparation, Properties, and Applications

Loy¹

2016

Handbook of Sol-Gel Science and Technology

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Mesoporous polysilsesquioxanes are an important class of hybrid organicinorganic materials with numerous applications in microelectronics, membranes, chromatographic materials, catalysis, and more. Prepared by sol-gel polymerization of monomers with trialkoxysilyl groups, these materials are based on siloxane networks modified by organic groups. Mesoporosity in these materials is formed through sol-gel polymerizations by themselves or can be directed into ordered arrays using surfactant templating. Surfactant templating allows mesopores in geometries ranging from cylindrical pores to gyroid porosities. Surfactant templating also enables the facile development of hierarchical structures where multiple modes of pores can independently coexist in the same material. Formulations for preparation of all of these mesoporous materials as monoliths, particles, and coatings will be discussed and examples will be provided.

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Free‐Blockage Mesoporous Silica Nanoparticles Loaded with Cerium Oxide as ROS‐Responsive and ROS‐Scavenging Nanomedicine

Purikova

Ткаченко

Veltruská

et al. 2022

Adv Funct Materials

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Mesoporous silica nanoparticles (MSNs) with reactive oxygen species (ROS)-responsive "nanogate" as drug delivery platforms are extensively investigated for biomedical applications. However, the physical blockages used to control the cargo release are often limited by their poor sealing ability and low biocompatibility. Herein, a design of free-blockage MSNs with methylthiopropyl units is proposed as the ROS-responsive switch. Four synthetic routes are compared with different precursors through either co-condensation or grafting methods to achieve the methylthio-functionalized MSNs. The quantity, localization, and chemical structure of the functional units, as well as the mesoporous structure of the silica can be tuned by optimizing the synthetic pathways to obtain desired final products. The ROS-responsive methylthiopropyl groups can be oxidized to sulfoxides in response to the presence of H 2 O 2 , leading to the hydrophobic/hydrophilic conversion of the MSNs. As a proof-of-concept design, ultrasmall cerium oxide nanoparticles are encapsulated into the functionalized MSNs and released out within 10 min scavenging more than 80% of the H 2 O 2 in an ROS-rich environment. This study provides a novel design of a free-blockage ROS-controlled release system loaded with ROS-scavenging nanoparticles for the future application of targeted drug delivery systems combined with antioxidant therapy.

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Evolution of Mesopores in Monolithic Macroporous Ethylene-Bridged Polysilsesquioxane Gels Incorporated with Nonionic Surfactant

Cited by 7 publications

References 12 publications

Synthesis of hierarchically porous polymethylsilsesquioxane monoliths with controlled mesopores for HPLC separation

Synthesis of hierarchically porous polymethylsilsesquioxane monoliths with controlled mesopores for HPLC separation

Mesoporous Polysilsesquioxanes: Preparation, Properties, and Applications

Free‐Blockage Mesoporous Silica Nanoparticles Loaded with Cerium Oxide as ROS‐Responsive and ROS‐Scavenging Nanomedicine

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