Advanced materials based on polymer cocrystalline forms

Abstract

Polymeric ''cocrystalline forms,'' that is, structures were a polymeric host and a low-molecular-mass guest are cocrystallized, were early recognized, and in many cases also well characterized by X-ray diffraction studies. However, only in the last two decades cocrystalline forms have received attention in material science, due to the ability (of few of them) to maintain an ordered polymer host structure even after guest removal, thus leading to the formation of ''nanoporous-crystalline forms,'' for which many applications in the fields of molecular separation and sensors have been proposed. Moreover, in the last decade, an accurate control of the orientation of the polymer cocrystalline phases has been achieved, thus leading to a control of the orientation of the guest molecules, not only in the crystalline phase but also in macroscopic films. In addition, on the basis of this orientation control, in the last few years, cocrystalline films where active molecules are present as guests of polymer cocrystalline phases have been proposed for optical, magnetic and electric applications. In the last few years, it has been also discovered that polymer cocrystallization, when induced by nonracemic guest molecules, can produce stable chiral optical films. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: [305][306][307][308][309][310][311][312][313][314][315][316][317][318][319][320][321][322] 2012

Nanoporous polymeric materials: A new class of materials with enhanced properties

“…The reason for this difference resides in the presence of a dense layer that covered the films developed by Yokoyama et al [54]. Finally, Rizzo et al [234] and Guerra and coworkers [184] found that s-PS films (thickness % 20 lm; pore size % 1 nm; porosity: 7%) exhibited chiral optical responses both in the infrared and in the UV-visible regions, opening the opportunity to achieve s-PS-based films with tunable chiral optical properties. Thus, nanoporous polymers seem to present enhanced optical behavior compared to the solid, which is mainly governed by the porosity of the system and not by the pore size.…”

“…However, new systems, such as polymers of intrinsic microporosity (PIMs) (rigid macromolecules that form nanoporous organic materials because of their inability to pack space efficiently [175]) [176][177][178][179], hypercrosslinked polymers [180][181][182], amorphous conjugated microporous polymers (CMPs) [183], and polymeric cocrystalline forms [184], have emerged to overcome these problems. For instance, McKeown et al [176] and later Budd and coworkers [177] developed different PIMs systems with pore widths between 0.6 and 0.7 nm (the density and membrane thickness were not specified).…”

Decisive properties of solvent able to form gels with syndiotactic polystyrene

“…Molecular volumes of the investigated molecules were calculated using winmostar. SP value of SPS is calculated to be 10.4 (cal/cm 3 and d intercalate (E, F) phase. As a reference, two typical WAXD patterns of SPS/guest d clathrate co-crystalline phase (A 0 ) and SPS/ guest d intercalate co-crystalline phase (F 0 ) are also shown in Fig.…”

An atomistic model of a disordered nanoporous solid: Interplay between Monte Carlo simulations and gas adsorption experiments

“…[1][2][3][4][5] In this paper we apply different computational techniques, along with experimental measures, to obtain a reliable atomistic structure for a recently synthesized hypercrosslinked polymer, with a peculiar porous structure and very interesting adsorption capacities for methane and carbon dioxide. 6 Nanoporous materials are of great interest for applications in gas storage, 7-9 molecular separation, [10][11][12] heterogeneous catalysis, [13][14][15] and the properties of such materials are critically affected by their porous structure, whose main parameters are the specific surface area, the micro-and mesoporous volumes and the pore size distribution. Remind that, according to the IUPAC rules, nanopores are classified as ultramicropores (with pore diameter below 0.7 nm), micropores (pore diameter between 0.7 and 2 nm) 65 and mesopores (between 2 and 50 nm).…”