Syndiotactic Polystyrene Clathrates with Polar Guest Molecules

Membranes based on sulfonated synditoactic polystyrene were thoroughly characterized by contrast variation SANS over a wide Q-range in dry and hydrated states. The film samples were prepared by solid-state sulfonation that allowed a uniform sulfonation of only the amorphous phase while preserving the crystallinity of the membrane. The samples were loaded with different guest molecules in either the amorphous (fullerenes) or the crystalline (toluene) regions, in order to vary the neutron contrast or to reproduce the conditions enabling an increased resistance of the membranes to chemical decomposition. The use of uni-axially deformed film samples and contrast variation with different H2O/D2O mixtures allowed for the identification and characterization of different structural levels with sizes between nm and μm, which form and evolve in the membrane morphology in dry and hydrated states and produce scattering features on different detection sectors and at different detection distances after the sample, depending on their size and orientation.

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Polymer Nanoporous and Co-crystalline Phases

MRS Proceedings ◽

10.1557/opl.2011.1321 ◽

2011 ◽

Vol 1366 ◽

Author(s):

Gaetano Guerra ◽

Christophe Daniel

Keyword(s):

Final Part ◽

Syndiotactic Polystyrene ◽

Crystalline Phases ◽

Guest Molecules ◽

Crystalline Structures ◽

Crystalline Forms

ABSTRACTThe first part of this presentation will be devoted to the description of the two nanoporous crystalline forms and of the various co-crystalline structures which can be obtained with syndiotactic polystyrene (s-PS). Then, the second part will deal with the co-crystals formed with active guest molecules (nonlinear active, fluorescent, photoreactive, chiral, ...) while the final part of the lecture will focus on the possible applications of materials characterized by nanoporous crystalline s-PS phases.

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Time-resolved small-angle neutron scattering study on guest-exchange processes in co-crystals of syndiotactic polystyrene

Journal of Applied Crystallography ◽

10.1107/s1600576713030343 ◽

2014 ◽

Vol 47 (1) ◽

pp. 6-13 ◽

Cited By ~ 6

Author(s):

Fumitoshi Kaneko ◽

Aurel Radulescu ◽

Koichi Ute

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Scattering Length ◽

Exchange Process ◽

Syndiotactic Polystyrene ◽

Crystalline Region ◽

Host Matrix ◽

Guest Molecules ◽

Time Resolved

Syndiotactic polystyrene (sPS) occupies a peculiar position among crystalline polymers: it forms co-crystals with many different kinds of chemical compounds, where the molecules are confined as guests in the regularly arranged cavities surrounded by the side phenyl groups. The guest molecules can be replaced smoothly by exposure to a vapour or a liquid of another compound, keeping the framework of the host polymer crystallites. It has been confirmed that the guest-exchange procedure is an effective way to incorporate a variety of chemical species into the crystalline region of syndiotactic polystyrene. In order to elucidate its characteristics, the guest-exchange process in co-crystals of syndiotactic polystyrene has been studied byin situtime-resolved small-angle neutron scattering measurements, exploiting the scattering length difference between fully protonated and deuterated isotopologues of guest compounds and employing fully deuterated syndiotactic polystyrene as the host matrix to avoid strong incoherent scattering. In this study, the guest-exchange process induced by exposure to the gas of small guest molecules was followed by monitoring of the reflections from crystalline lamellae. The lamellar reflections showed significant variations in intensity during the guest exchange, from which the diffusion coefficients of the guest molecules in the crystalline region could be evaluated.

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Dielectric Relaxation of Guest Molecules in a Clathrate Structure of Syndiotactic Polystyrene

The Journal of Physical Chemistry B ◽

10.1021/jp304687m ◽

2012 ◽

Vol 116 (49) ◽

pp. 14461-14469 ◽

Cited By ~ 8

Author(s):

Osamu Urakawa ◽

Fumitoshi Kaneko ◽

Hideo Kobayashi

Keyword(s):

Dielectric Relaxation ◽

Syndiotactic Polystyrene ◽

Guest Molecules

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Monomeric and Dimeric Carboxylic Acid in Crystalline Cavities and Channels of Delta and Epsilon Forms of Syndiotactic Polystyrene

Polymers ◽

10.3390/polym13193330 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3330

Author(s):

Antonietta Cozzolino ◽

Guglielmo Monaco ◽

Christophe Daniel ◽

Paola Rizzo ◽

Gaetano Guerra

Keyword(s):

Carboxylic Acid ◽

Hexanoic Acid ◽

Ftir Spectra ◽

Syndiotactic Polystyrene ◽

Guest Molecules ◽

Characterization Study ◽

Polarized Ftir ◽

Crystalline Forms

Delta (δ) and epsilon (ε) co-crystalline forms of syndiotactic polystyrene with a carboxylic acid guest were obtained by sorption of liquid hexanoic acid in syndiotactic polystyrene films exhibiting delta and epsilon nanoporous-crystalline forms. The characterization study is facilitated by axially stretched syndiotactic polystyrene films, used both for polarized FTIR spectra and for WAXD fiber patterns. Particularly informative are two carbonyl-stretching FTIR peaks, attributed to monomeric and dimeric hexanoic acid. The dichroism of these carbonyl peaks indicates that both delta and epsilon phases are able to include hexanoic acid as isolated guest molecules, while only the epsilon phase is also able to include dimeric hexanoic acid molecules in its crystalline channels. The inclusion of both isolated and dimeric hexanoic acid species in the epsilon form crystalline channels produces extremely fast hexanoic acid uptakes by syndiotactic polystyrene epsilon form films.

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