Morphology and pore structure of silica xerogels made at low pH

Curran, Matthew D.; Stiegman, A. E.

doi:10.1016/s0022-3093(99)00237-9

Cited by 73 publications

(52 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,6,14,[18][19][20][21][22] This phenomenon also results in an increase in the surface area with increasing acid and base concentrations, which is consistent with the earlier reported results. 6,14,[18][19][20]22 The highest surface area (~913 m 2 g . Thus, the surface area of the silica particles is also a vital factor to control the interactions between the gel matrix and the dye molecules filled in the pores.…”

Section: Methodssupporting

confidence: 90%

“…15,22 For the OS D samples, the increase in the dye concentration reduced the pore size and surface area resulting in the collision and aggregation of dye molecules. 14,20,21 and also depicted in the Table 2, the increase in A for the OSA samples shifted the pore size distribution towards the larger pore size indicating an increase in the pore size. A similar behavior is also noticed for the pore size distributions of TSB samples having broad distribution curves as compared to the OSA samples.…”

Section: Methodsmentioning

confidence: 59%

“…2,3,14 In the highly acidic region of sol (pH ≤ 2.5), the silica particulates grow up almost non-linearly, hence, form relatively less dense acid catalyzed OS samples with increased micropore size. 6,14,[19][20][21][22] In the acid-base catalyzed (TS) samples prepared with the condition 2.5 < pH ≤ 7, the silica particles grow up randomly resulting in loosely packed, cluster-like structures having mesopores and large size of silica particles, which can be seen clearly below. 14,[18][19][20][21][22] This resulted in transparent acid-catalyzed OS samples (pH ≤ 2.5) and translucent or opaque acid-base catalyzed TS samples (pH > 2.5).…”

Section: Methodsmentioning

confidence: 99%

“…6,14,[19][20][21][22] In the acid-base catalyzed (TS) samples prepared with the condition 2.5 < pH ≤ 7, the silica particles grow up randomly resulting in loosely packed, cluster-like structures having mesopores and large size of silica particles, which can be seen clearly below. 14,[18][19][20][21][22] This resulted in transparent acid-catalyzed OS samples (pH ≤ 2.5) and translucent or opaque acid-base catalyzed TS samples (pH > 2.5). 4,6,14,[18][19][20][21][22] This phenomenon also results in an increase in the surface area with increasing acid and base concentrations, which is consistent with the earlier reported results.…”

Section: Methodsmentioning

confidence: 99%

“…14,[18][19][20][21][22] This resulted in transparent acid-catalyzed OS samples (pH ≤ 2.5) and translucent or opaque acid-base catalyzed TS samples (pH > 2.5). 4,6,14,[18][19][20][21][22] This phenomenon also results in an increase in the surface area with increasing acid and base concentrations, which is consistent with the earlier reported results. 6,14,[18][19][20]22 The highest surface area (~913 m 2 g .…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

2003

Bulletin of the Korean Chemical Society

View full text Add to dashboard Cite

Physical properties and microstructure of new coumarin 4 doped SiO 2 -PDMS ORMOSILs, synthesized by one-step (OS, acid-catalysis) and two-step (TS, acid-base catalysis) routes of sol-gel method with varying pH (0.6 to 7) and dye content (5 × 10 −4 to 5 × 10 −2 mole), are reported. BET, UV-visible spectroscopy and SEM were used for characterizations. The increase in acid or base concentration increased the size of pores and aggregated silica particles. The samples with pH ≤ 2.5 were transparent and attributed to the small size of pores (~20 Å) and silica particles. The samples with pH > 2.5 were translucent or opaque due to non-uniform pore system formed by voids and large aggregated silica particles. The surface area was found a key factor controlling the interactions between the gel matrix and the dye. The OS samples with the highest dye concentration exhibited the minimal values of pore size, surface area and silica particle size, resulting in the concentration-quenching phenomenon.

show abstract

Section: Methodssupporting

confidence: 90%

Section: Methodsmentioning

confidence: 59%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

2003

Bulletin of the Korean Chemical Society

View full text Add to dashboard Cite

show abstract

In Situ Surface Assembly Derived Ultralow Refractive Index MgF₂–SiO₂ Hybrid Film for Tri‐Layer Broadband Antireflective Coating

Cui

Ding

Wang

et al. 2016

Advanced Optical Materials

View full text Add to dashboard Cite

multilayers with gradient refractive index decreasing from the substrate index to that of air. [8][9][10] So the key challenge in the fabrication of broadband AR coatings lies in fi nding fi lm materials with tunable refractive index especially a low-index coating for top layer. In high power laser system, the frequency conversion process in which the fundamental beam of 1053 nm is converted to the second harmonic beam of 527 nm fi rstly, and fi nally converted to the third harmonic beam of 351 nm by two frequency conversion crystals makes many optical components subject to transmission of three wavelengths laser beams simultaneously. To reduce the energy loss, it is highly desirable to develop AR coatings exhibiting high transmittance simultaneously at 351, 527, and 1053 nm. [ 11 ] This broadband AR coating working in several specifi c wavelengths faces greater challenges compared to the common broadband AR coating because the peak position must be tailored in specifi c wavelengths by precisely controlling the refractive index and fi lm thickness of each layer. Any slight deviation of refractive index or fi lm thickness will lead to the shift of peak position and thus fail in reaching the required optical performance. For all above diffi culties, many approaches cannot already meet the requirement such as reactive ion etching process [ 12,13 ] and the heteroepitaxial growth of nanorods because of the complex process, incapable precise control of refractive index and fi lm thickness, high cost of these techniques, and non-availability in a large area substrate. [ 14 ] Fortunately, sol-gel process provides a preferable choice due to the great advantage on precise control of refractive index by tailoring the sol microstructure and chemical composition, excellent adhesion to glass surface, low process temperature, and good homogeneity. [15][16][17][18] The sol-gel derived silica and magnesium fl uoride coatings, characterized by low refractive index of 1.45 and 1.38 respectively, low dispersion in UV region, and good stability, have become the best choice of fi lm materials in high power laser systems. [19][20][21][22] There have been many reports devoted to tune the refractive index of silica coating based on the acid-catalyzed and base-catalyzed procedure. For instance, Thomas prepared

show abstract

Evaluation of the interactions between collagen and the surface of a bioactive glass during in vitro test

Oréfice

Hench

Brennan

2008

J Biomedical Materials Res

View full text Add to dashboard Cite

Interactions between biomaterials and the body environment usually determine the lifetime and performance of biomedical devices used as implants. Among a variety of different types of interactions that occur whenever biomaterials are implanted into the body, adsorption of biomacromolcules onto the surface of biomaterials can guide other relevant processes such as cell attachment, cell differentiation, cell proliferation, tissue growth and biomaterials degradation. In this work, fundamental mechanisms associated with the interactions between collagen and the surface of biomaterials were studied by using Atomic Force Microscopy (AFM). The ultimate goal of this work is to isolate and simulate phenomena occurring at the molecular level, when biological entities are brought in contact with biomaterials. These results can then be used to design and test new biomedical devices. This manuscript reports the evaluation of interactions between collagen and the surface of bioactive glasses. These bioactive glasses are known to bond to soft and hard tissues through the formation of a hydroxy-carbonate-apatite layer. Collagen was grafted onto AFM cantilevers. AFM force-displacement curves were obtained using these modified tips against the surface of a bioactive glass at different stages of an in vitro test performed in a simulated body fluid. The results showed that the structure of the bioactive glass surface affects the adsorption of collagen on the biomaterial. The magnitude of the adhesion force measured is highly dependent on the deposition of a hydroxyl-carbonate-apatite at the surface of the glass.

show abstract

Morphology and pore structure of silica xerogels made at low pH

Cited by 73 publications

References 10 publications

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

In Situ Surface Assembly Derived Ultralow Refractive Index MgF₂–SiO₂ Hybrid Film for Tri‐Layer Broadband Antireflective Coating

Evaluation of the interactions between collagen and the surface of a bioactive glass during in vitro test

Contact Info

Product

Resources

About

Morphology and pore structure of silica xerogels made at low pH

Cited by 73 publications

References 10 publications

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO2-PDMS ORMOSIL

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO2-PDMS ORMOSIL

In Situ Surface Assembly Derived Ultralow Refractive Index MgF2–SiO2 Hybrid Film for Tri‐Layer Broadband Antireflective Coating

Evaluation of the interactions between collagen and the surface of a bioactive glass during in vitro test

Contact Info

Product

Resources

About

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

Influence of pH and Dye Concentration on the Physical Properties and Microstructure of New Coumarin 4 Doped SiO₂-PDMS ORMOSIL

In Situ Surface Assembly Derived Ultralow Refractive Index MgF₂–SiO₂ Hybrid Film for Tri‐Layer Broadband Antireflective Coating