Phase separation in PMMA/silica sol-gel systems

Kátia Fraga Silveira; Inez Valéria P. Yoshida; Suzana Pereira Nunes

doi:10.1016/0032-3861(95)95921-M

Phase separation in PMMA/silica sol-gel systems

Kátia Fraga Silveira, Inez Valéria P. Yoshida, Suzana Pereira Nunes^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

76 Scopus citations

Abstract

The mechanism of phase separation of sol-gel alkoxy-derived silica systems obtained by acid catalysis in the presence of poly(methyl methacrylate) (PMMA) and tetrahydrofuran was investigated by light scattering. Spinodal decomposition (SD) was confirmed for systems with intermediate PMMA/alkoxy compositions occurring with a simultaneous viscosity increase. The initial stages of phase separation followed the linear theory proposed by Cahn. For systems with low PMMA content, a behaviour typical of nucleation and growth was detected. In this case gelation took place after demixing. The morphology of the final PMMA/silica hybrid material was investigated by scanning and transmission electron microscopy with element-specific analysis. A matrix/disperse domains morphology was also verified for systems which demixed by SD, indicating that phase coarsening occurs. A micellar/lamellar microstructure was observed inside the separated phases.

Original language	English (US)
Pages (from-to)	1425-1434
Number of pages	10
Journal	Polymer
Volume	36
Issue number	7
DOIs	https://doi.org/10.1016/0032-3861(95)95921-M
State	Published - Mar 1995
Externally published	Yes

Keywords

PMMA/silica
phase separation
sol-gel

ASJC Scopus subject areas

Organic Chemistry
Polymers and Plastics
Materials Chemistry

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10.1016/0032-3861(95)95921-M

Cite this

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title = "Phase separation in PMMA/silica sol-gel systems",

abstract = "The mechanism of phase separation of sol-gel alkoxy-derived silica systems obtained by acid catalysis in the presence of poly(methyl methacrylate) (PMMA) and tetrahydrofuran was investigated by light scattering. Spinodal decomposition (SD) was confirmed for systems with intermediate PMMA/alkoxy compositions occurring with a simultaneous viscosity increase. The initial stages of phase separation followed the linear theory proposed by Cahn. For systems with low PMMA content, a behaviour typical of nucleation and growth was detected. In this case gelation took place after demixing. The morphology of the final PMMA/silica hybrid material was investigated by scanning and transmission electron microscopy with element-specific analysis. A matrix/disperse domains morphology was also verified for systems which demixed by SD, indicating that phase coarsening occurs. A micellar/lamellar microstructure was observed inside the separated phases.",

keywords = "PMMA/silica, phase separation, sol-gel",

author = "Silveira, {K{\'a}tia Fraga} and Yoshida, {Inez Val{\'e}ria P.} and Nunes, {Suzana Pereira}",

year = "1995",

month = mar,

doi = "10.1016/0032-3861(95)95921-M",

language = "English (US)",

volume = "36",

pages = "1425--1434",

journal = "Polymer",

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publisher = "Elsevier",

number = "7",

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TY - JOUR

T1 - Phase separation in PMMA/silica sol-gel systems

AU - Silveira, Kátia Fraga

AU - Yoshida, Inez Valéria P.

AU - Nunes, Suzana Pereira

PY - 1995/3

Y1 - 1995/3

N2 - The mechanism of phase separation of sol-gel alkoxy-derived silica systems obtained by acid catalysis in the presence of poly(methyl methacrylate) (PMMA) and tetrahydrofuran was investigated by light scattering. Spinodal decomposition (SD) was confirmed for systems with intermediate PMMA/alkoxy compositions occurring with a simultaneous viscosity increase. The initial stages of phase separation followed the linear theory proposed by Cahn. For systems with low PMMA content, a behaviour typical of nucleation and growth was detected. In this case gelation took place after demixing. The morphology of the final PMMA/silica hybrid material was investigated by scanning and transmission electron microscopy with element-specific analysis. A matrix/disperse domains morphology was also verified for systems which demixed by SD, indicating that phase coarsening occurs. A micellar/lamellar microstructure was observed inside the separated phases.

AB - The mechanism of phase separation of sol-gel alkoxy-derived silica systems obtained by acid catalysis in the presence of poly(methyl methacrylate) (PMMA) and tetrahydrofuran was investigated by light scattering. Spinodal decomposition (SD) was confirmed for systems with intermediate PMMA/alkoxy compositions occurring with a simultaneous viscosity increase. The initial stages of phase separation followed the linear theory proposed by Cahn. For systems with low PMMA content, a behaviour typical of nucleation and growth was detected. In this case gelation took place after demixing. The morphology of the final PMMA/silica hybrid material was investigated by scanning and transmission electron microscopy with element-specific analysis. A matrix/disperse domains morphology was also verified for systems which demixed by SD, indicating that phase coarsening occurs. A micellar/lamellar microstructure was observed inside the separated phases.

KW - PMMA/silica

KW - phase separation

KW - sol-gel

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U2 - 10.1016/0032-3861(95)95921-M

DO - 10.1016/0032-3861(95)95921-M

M3 - Article

AN - SCOPUS:0029274158

SN - 0032-3861

VL - 36

SP - 1425

EP - 1434

JO - Polymer

JF - Polymer

IS - 7

ER -

Phase separation in PMMA/silica sol-gel systems

Abstract

Keywords

ASJC Scopus subject areas

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