PMMA-impregnated silica gels: synthesis and characterization

Abramoff, Bennet; Klein, Lisa C.

doi:10.1117/12.22563

Cited by 18 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the first approach, the impregnation of porous oxide gels with organics is followed by an in situ polymerization initiated by thermal or irradiation methods. [31][32][33] In the second approach, polymers can be trapped within the oxide gel network if the hydrolysis and condensation of metal alkoxide are carried out in the presence of preformed polymers. [34][35][36][37][38][39][40][41][42] Optically transparent composite materials can be obtained if there is no macro-or microphase separation during both the gel forming and drying process.…”

Section: Introductionmentioning

confidence: 99%

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

1996

View full text Add to dashboard Cite

Organic/inorganic hybrid materials prepared by the sol-gel approach have rapidly become a fascinating new field of research in materials science. The explosion of activity in this area in the past decade has made tremendous progress in both the fundamental understanding of the sol-gel process and the development and applications of new organic/inorganic hybrid materials. In this review, a brief summary of the research activities in the field of organic/inorganic nanocomposite materials and a general background of the sol-gel chemistry are first given. The emphasis of this report, however, is placed on the synthesis, structureproperty response, and potential applications of the organic/inorganic hybrid networks that possess chemical bonding between the organic and inorganic phases, particularly those systems that were developed in our laboratory since 1985.

show abstract

Section: Introductionmentioning

confidence: 99%

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

1996

View full text Add to dashboard Cite

show abstract

“…12 The controlled porosity (average pore diameters of about 5-20 nm) and homogeneity of the sol-gel processed materials allow their utilization as excellent thermally, chemically, and dimensionally stable matrixes (e.g., in pharmaceutical, medical, and optical applications) in virtually any form: monoliths, thin films, coatings, and composites. 12 The incorporation of the environmentally stable and optically transparent PMMA into the SiO 2 matrix (index-matching process) results in dual matrixes with a range of advanced physicochemical and mechanical characteristics 8,9 and multifunctional photonic applications. 13,14 In this article, we present a dielectric study performed by means of the thermally stimulated depolarization currents (TSDC) technique 15 in a range of PMMA-based materials: bulk amorphous PMMA, diphasic PMMA + SiO 2 composites (PMMA polymerized in situ in 5 nm silica gels), and the same matrixes with dispersed laser-active dyes.…”

Section: Introductionmentioning

confidence: 99%

“…Poly(methyl methacrylate) (PMMA) is widely recognized as a polymer of high technological and industrial impact − Interesting examples of porous substrates are some natural and synthetic micropore structures (e.g., the zeolitic molecular sieves , ) and especially the mesopore inorganic hosts (e.g., TiO 2 and SiO 2 2 ) developed by the sol−gel method . The controlled porosity (average pore diameters of about 5−20 nm) and homogeneity of the sol−gel processed materials allow their utilization as excellent thermally, chemically, and dimensionally stable matrixes (e.g., in pharmaceutical, medical, and optical applications) in virtually any form: monoliths, thin films, coatings, and composites .…”

Section: Introductionmentioning

confidence: 99%

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics

Kalogeras

Vassilikou‐Dova

2001

J. Phys. Chem. B

View full text Add to dashboard Cite

Modifications in the molecular dynamics of the side-chain relaxation in poly(methyl methacrylate) (PMMA) have been recorded by monitoring the thermally stimulated depolarization currents (TSDC) β-relaxation band of PMMA in three systems: bulk PMMA, PMMA polymerized in situ in porous SiO2, and lasing matrixes with rhodamine 6G/Cl- (R6G) and a perylene derivative (PG). To study the different types of inter- and intramolecular interactions, a range of dye concentrations and different polymerization initiators have been tested. In PMMA + SiO2, the low-temperature (LT) shift of the β-band and the increase of the energy barriers (W) associated with the side-chain (re)orientation are attributed to various counterbalancing effects. A scheme of extensive hydrogen-bond interactions (surface or chemical effect) between the ester carbonyls of PMMA and the silicic acid pore surface is used to explain the overall increase in the distributed energy barriers. In contrast, the reduction of the polymer's chain entanglements and the increase in the free volume (structural or physical effect), due to the pore-directed polymerization, are considered to loosen up several steric hindrances on the rotational motion. The modification of the relaxation times spectrum prompts the shift of the β-relaxation in PMMA + SiO2. In R6G + PMMA, the drastic LT shift of the β-band indicates the partial coupling between the chromophores and the side-group rotations. The TSDC spectrum does not present a rotational relaxation of the polar rhodamine dye. In R6G + PMMA + SiO2, the presence of the chromophores on the pore surfaces and the corresponding decrease of the “effective” average pore diameters available for MMA diffusion and PMMA growth balance the physical and chemical effects, as depicted in the similarity of the energy distributions. The speedup of the β-relaxation with increasing dye content is ascribed to the reduced exposure of the side groups to chemical effects. The positive energy shift in PG + PMMA + SiO2 can be explained by considering the mixing of PG and PMMA, which permits strong hydrogen-bonding interactions and simultaneously reduces PMMA's free volume. TSDC signals around room temperature (RT) are tentatively discussed in terms of a Maxwell−Wagner−Sillars (MWS) polarization mode at the PMMA−SiO2 interface.

show abstract

“…Owing to its excellent optical and mechanical properties, PMMA has been a first-choice component for the preparation of inorganic-organic composites. [1,[4][5] Quantum dots (QDs) are semiconductor nanocrystals with bright, stable and size-tunable photoluminescence (PL). Incorporation of QDs at high densities in polymer thin films is promising for the development of nanoscale sensors, light-emitting diodes, and photovoltaic devices.…”

Section: Introductionmentioning

confidence: 99%

Fluorescent Biocompatible Tactic PMMA-QDs Thin Films

Lester¹,

Abdulkadir²,

Washburn³

et al. 2014

Proceedings of the 2015 International Conference on Material Science and Applications

View full text Add to dashboard Cite

Poly(methyl methacrylate) thin films were prepared through solvent casting method followed by thermal treatment to completely remove the residual solvent. All three different tactic PMMAs were studied; the PMMA solution was made in chloroform at various concentrations, with 0.1wt% QDs added against the polymer mass in the polymer solution. PMMA-QDs thin films as well as the pristine PMMA thin film (as control sample) were characterized using a variety of analytical techniques to probe their structure, functionalities, and respective physicochemical properties including thickness, surface wettability, fluorescence emission, and biocompatibility using HeLa mammalian cell as a model cell line. The fluorescence emission steadily increased when the concentration of PMMA increases. The wettability test showed i-PMMA to be more hydrophilic with a smaller contact angle than the other tacticity, while a-PMMA showed to be more hydrophobic with a larger contact angle than the other tacticity. All PMMA-QDs thin films used in co-culturing with HeLa cells supported their growth and proliferation.

show abstract

PMMA-impregnated silica gels: synthesis and characterization

Cited by 18 publications

References 0 publications

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics

Fluorescent Biocompatible Tactic PMMA-QDs Thin Films

Contact Info

Product

Resources

About

PMMA-impregnated silica gels: synthesis and characterization

Cited by 18 publications

References 0 publications

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

Organic/Inorganic Hybrid Network Materials by the Sol−Gel Approach

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO2 Matrixes Doped with Luminescent Organics

Fluorescent Biocompatible Tactic PMMA-QDs Thin Films

Contact Info

Product

Resources

About

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics