scholarly journals Effect of boron incorporation on the bioactivity, structure, and mechanical properties of ordered mesoporous bioactive glasses

2020 ◽  
Vol 8 (7) ◽  
pp. 1456-1465 ◽  
Author(s):  
Leonie Deilmann ◽  
Oliver Winter ◽  
Bianca Cerrutti ◽  
Henrik Bradtmüller ◽  
Christopher Herzig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Self Assembly ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
Structure Directing Agent ◽  
Structural Investigations ◽  
Ordered Mesoporous ◽  
Evaporation Induced Self Assembly

B2O3 doped (0.5–15 mol%) ordered mesoporous bioactive glasses were synthesized via sol–gel based evaporation-induced self-assembly using P123 as a structure directing agent and characterized by biokinetic, mechanical and structural investigations.

Fabrication of Hierarchically Porous Bioactive Glass Ceramics

2007 ◽  
Vol 361-363 ◽  
pp. 285-288 ◽  
Author(s):  
Hui Suk Yun ◽  
Seung Eon Kim ◽  
Yong Taek Hyun
Keyword(s):  
Block Copolymers ◽  
Rapid Prototyping ◽  
Self Assembly ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Methyl Cellulose ◽  
Amphiphilic Block Copolymers ◽  
Bioactive Glasses ◽  
Polymer Templating ◽  
Evaporation Induced Self Assembly

Hierarchically 3D porous bioactive glasses (BGs) with various combination of both pore sizes and pore structures have been produced by multi-polymer templating, such as amphiphilic block copolymers, poly urethane (PU) forms, poly styrene (PS) beads, or methyl cellulose (MC), sol-gel method, evaporation-induced self-assembly process, and rapid prototyping technique. The amphiphilic block copolymers used for producing the meso pores into the BGs, which induces large specific surface area and subsequently carries with good bone-forming bioactivity of BGs. Each poly urethane form, poly styrene bead, and methyl cellulose adapted for the fabrication of macro pores. The rapid prototyping (RP) techniques introduced to produce 3D BGs scaffolds with giant pores.

scholarly journals Nanostructured Mesoporous Silica Wires with Intrawire Lamellae via Evaporation-Induced Self-Assembly in Space-Confined Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Michael Z. Hu ◽  
Donglu Shi ◽  
Douglas A. Blom
Keyword(s):  
Mesoporous Silica ◽  
Aging Time ◽  
Self Assembly ◽  
Water Solution ◽  
Sol Gel ◽  
Vacuum Impregnation ◽  
Anodized Aluminum ◽  
Structure Directing Agent ◽  
Evaporation Induced Self Assembly ◽  
Silica Precursor

Evaporation-induced self-assembly (EISA) of silica sol-gel ethanol-water solution mixtures with block-copolymer were studied inside uniform micro/nano-channels. Nanostructured mesoporous silica wires, with various intrawire self-assembly structures including lamellae, were prepared via EISA process but in space-confined channels with the diameter ranging from 50 nm to 200 nm. Membranes made of anodized aluminum oxide (AAO) and track-etched polycarbonate (EPC) were utilized as the arrays of space-confined channels (i.e., 50, 100, and 200 nm EPC and 200 nm AAO) for infiltration and drying of mixture solutions; these substrate membranes were submerged in mixture solutions consisting of a silica precursor, a structure-directing agent, ethanol, and water. After the substrate channels were filled with the solution under vacuum impregnation, the membrane was removed from the solution and dried in air. The silica precursor used was tetraethyl othosilicate (TEOS), and the structure-directing agent employed was triblock copolymer Pluronic-123 (P123). It was found that the formation of the mesoporous nanostructures in silica wires within uniform channels were significantly affected by the synthesis conditions including (1) preassemble TEOS aging time, (2) the evaporation rate during the vacuum impregnation, and (3) the air-dry temperature. The obtained intrawire structures, including 2D hexagonal rods and lamellae, were studied by scanning transmission electron microscopy (STEM). A steric hindrance effect seems to explain well the observed polymer-silica mesophase formation tailored by TEOS aging time. The evaporation effect, air-drying effect, and AAO versus EPC substrate effect on the mesoporous structure of the formed silica wires were also presented and discussed.

scholarly journals Mesoporous MgTa2O6 thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

2012 ◽  
Vol 3 ◽  
pp. 123-133 ◽  
Author(s):  
Jin-Ming Wu ◽  
Igor Djerdj ◽  
Till von Graberg ◽  
Bernd M Smarsly
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Self Assembly ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Ordered Mesoporous ◽  
Mesoporous Film ◽  
Evaporation Induced Self Assembly ◽  
Poly Ethylene

Ordered mesoporous, crystalline MgTa2O6 thin films with a mesoscopic nanoarchitecture were synthesized by evaporation-induced self-assembly (EISA) in combination with a sol–gel procedure. Utilization of novel templates, namely the block copolymers KLE (poly(ethylene-co-butylene)-b-poly(ethylene oxide)) and PIB6000 (CH3C(CH3)2(CH2C(CH3)2)107CH2C(CH3)2C6H4O(CH2CH2O)100H), was the key to achieving a stable ordered mesoporous structure even upon crystallization of MgTa2O6 within the mesopore walls. The effect of the calcination temperature on the ability of the mesoporous films to assist the photodegradation of rhodamine B in water was studied. As a result, two maxima in the photocatalytic activity were identified in the calcination temperature range of 550–850 °C, peaking at 700 °C and 790 °C, and the origin of this was investigated by using temperature-dependent X-ray scattering. Optimal activity was obtained when the mesoporous film was heated to 790 °C; at this temperature, crystallinity was significantly high, with MgTa2O6 nanocrystals of 1.6 nm in size (averaged over all reflections), and an ordered mesoporous structure was maintained. When considering the turnover frequency of such photocatalysts, the optimized activity of the present nanoarchitectured MgTa2O6 thin film was ca. four times that of analogous anatase TiO2 films with ordered mesopores. Our study demonstrated that high crystallinity and well-developed mesoporosity have to be achieved in order to optimize the physicochemical performance of mesoporous metal-oxide films.

Solvent-tuning of ordered mesoporous silicas prepared through evaporation-induced self-assembly templated by poly(ethylene oxide-b-ε-caprolactone)

RSC Advances ◽  
2014 ◽  
Vol 4 (105) ◽  
pp. 61012-61021 ◽  
Author(s):  
Wei-Cheng Chu ◽  
Chen-Xin Lin ◽  
Shiao-Wei Kuo
Keyword(s):  
Ethylene Oxide ◽  
Self Assembly ◽  
Mesoporous Silicas ◽  
Size Distributions ◽  
Ordered Mesoporous ◽  
Pore Size Distributions ◽  
Evaporation Induced Self Assembly ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Selection Of

Highly ordered mesoporous silicas having narrow pore size distributions and various morphologies merely through selection of an appropriate solvent.

Hybrid Bioactive Glass-Polyvinyl Alcohol Prepared by Sol-Gel

2008 ◽  
Vol 587-588 ◽  
pp. 62-66 ◽  
Author(s):  
Hermes S. Costa ◽  
Alexandra A.P. Mansur ◽  
Edel Figueiredo Barbosa-Stancioli ◽  
Marivalda Pereira ◽  
Herman S. Mansur
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Degree Of Hydrolysis ◽  
Bioactive Glasses ◽  
Composite Foams ◽  
Composition Ratios ◽  
Hybrid Scaffolds ◽  
Hydrolysis Of

Bioactive glasses are materials that have been used for the repair and reconstruction of diseased bone tissues, as they exhibit direct bonding with human bone tissues. However, bioactive glasses have low mechanical properties compared to cortical and cancellous bone. On the other hand, composite materials of biodegradable polymers with inorganic bioactive glasses are of particular interest to engineered scaffolds because they often show an excellent balance between strength and toughness and usually improved characteristics compared to their individual components. Composite bioactive glass-polyvinyl alcohol foams for use as scaffolds in tissue engineering were previously developed using the sol-gel route. The goal of this work was the synthesis of composite foams modified with higher amounts of PVA. Samples were characterized by morphological and chemical analysis. The mechanical behavior of the obtained materials was also investigated. The degree of hydrolysis of PVA, concentration of PVA solution and different PVA-bioactive glass composition ratios affect the synthesis procedure. Foams with up to 80 wt% polymer content were obtained. The hybrid scaffolds obtained exhibited macroporous structure with pore size varying from 50 to 600 µm and improved mechanical properties.

Ordered mesoporous carbon in solid-phase microextraction for analysis of volatile organic compounds in water samples

2019 ◽  
Vol 11 (29) ◽  
pp. 3741-3749
Author(s):  
Bo Liu ◽  
Yaqiong Hao ◽  
Lixiao Wang ◽  
Mengyun Li ◽  
Hui Jiang
Keyword(s):  
Self Assembly ◽  
Mesoporous Carbon ◽  
Solid Phase ◽  
Dip Coating ◽  
Ordered Mesoporous Carbon ◽  
Ordered Mesoporous ◽  
Volatile Organic ◽  
Coating Method ◽  
Evaporation Induced Self Assembly ◽  
Dip Coating Method

An ordered mesoporous carbon (OMC) film supported on graphite fiber was prepared by a dip-coating method combined with a solvent evaporation induced self-assembly (EISA) strategy.

scholarly journals A Comparison of Bioactive Glass Scaffolds Fabricated ‎by Robocasting from Powders Made by Sol–Gel and Melt-Quenching Methods

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 615
Author(s):  
Basam A. E. Ben-Arfa ◽  
Robert C. Pullar
Keyword(s):  
Mechanical Properties ◽  
Bioactive Glass ◽  
Bone Growth ◽  
Sol Gel ◽  
Glass Network ◽  
Silica Content ◽  
Bioactive Glasses ◽  
Phosphorous Content ◽  
High Silica ◽  
45S5 Bioglass

Bioactive glass scaffolds are used in bone and tissue biomedical implants, and there is great interest in their fabrication by additive manufacturing/3D printing techniques, such as robocasting. Scaffolds need to be macroporous with voids ≥100 m to allow cell growth and vascularization, biocompatible and bioactive, with mechanical properties matching the host tissue (cancellous bone for bone implants), and able to dissolve/resorb over time. Most bioactive glasses are based on silica to form the glass network, with calcium and phosphorous content for new bone growth, and a glass modifier such as sodium, the best known being 45S5 Bioglass®. 45S5 scaffolds were first robocast in 2013 from melt-quenched glass powder. Sol–gel-synthesized bioactive glasses have potential advantages over melt-produced glasses (e.g., greater porosity and bioactivity), but until recently were never robocast as scaffolds, due to inherent problems, until 2019 when high-silica-content sol–gel bioactive glasses (HSSGG) were robocast for the first time. In this review, we look at the sintering, porosity, bioactivity, biocompatibility, and mechanical properties of robocast sol–gel bioactive glass scaffolds and compare them to the reported results for robocast melt-quench-synthesized 45S5 Bioglass® scaffolds. The discussion includes formulation of the printing paste/ink and the effects of variations in scaffold morphology and inorganic additives/dopants.

Fabrication and characterization of mesoporous borosilicate glasses with different boron contents

2007 ◽  
Vol 22 (7) ◽  
pp. 1834-1838 ◽  
Author(s):  
Tongping Xiu ◽  
Qian Liu ◽  
Jiacheng Wang
Keyword(s):  
Boric Acid ◽  
Self Assembly ◽  
Sol Gel ◽  
Sorption Isotherms ◽  
Mesoporous Structure ◽  
Borosilicate Glasses ◽  
Whole Process ◽  
Transmission Electron ◽  
Evaporation Induced Self Assembly ◽  
The Stability

A series of wormhole-like mesoporous borosilicate glasses (MBSGs) with different compositions has been prepared by a combination of surfactant templating, sol-gel methods, and evaporation-induced self-assembly processes. Small-angle x-ray diffraction, high-resolution transmission electron microscopy, and N2 sorption isotherms analysis showed that all the MBSGs prepared possess the mesoporous structure. However, the stability of the mesoporous structure is strongly affected by the boron contents. When boron content was increased, boric acid was found in the final product, and the mesoporous structure was partially degraded. The formation and loss of boric acid through the whole process may account for the partial collapse of the mesostructure.

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