Supported Particle Track Etched Polyimide Membranes:  A Grazing Incidence Small-Angle X-ray Scattering Study

Hermsdorf, N.; Sahre, Karin; Volodin, Pylyp; Stamm, Manfred; Kj, Eichhorn; Cunis, S.; Gehrke, Rainer; Panagiotou, Panteleimon; Titz, T.; Müller‐Buschbaum, Peter

doi:10.1021/la048313l

Cited by 6 publications

(3 citation statements)

References 34 publications

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“…Moreover, the structures of the ILs were probed using small- and wide-angle X-ray scattering (SAXS and WAXS). − The WAXS data for all four ILs showed a strong intensity peak around the scattering vector of q ≈ 15 nm –1 (Figure a), which reflects the intermolecular structure, that is, the distance between successive neighbor ion shells in the IL. For three ILs (except [TMP]Tos), SAXS reveals a small and very diffuse peak at about q ≈ 3 to 4 nm –1 (Figure b).…”

supporting

confidence: 66%

Peculiar Behavior of Azolium Azolate Energetic Ionic Liquids

Pogodina

Metwalli

Müller‐Buschbaum

et al. 2011

J. Phys. Chem. Lett.

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b S Supporting Information I onic liquids (ILs) are liquids formed by ions whose properties are tuned by the cation/anion combination. A great variety of possible cation/anion combinations drives the development of novel ILs and allows flexibility in tailoring ILs for specific applications. Azolium azolates possess superior energy density and therefore are targeted for propulsion and explosives applications. 1À4 However, the fundamental physical properties of these ILs and their full potential are not yet explored.Common ILs, which have already been widely studied, possess an organic cation and an inorganic anion. Azolium azolates consist of an organic azolium cation and an organic azolate anion; that is, the anion has the structure of an aromatic planar rich in nitrogen ring, which may lead to specific behavior of ILs. It is already accepted that ILs are complex fluids and show structuring in their liquid phases. Experimental 5,6 and theoretical 7 evidence suggests that ILs are heterogeneous on the nanoscale with polar and apolar domains in the bulk liquid, which makes them similar to bicontinuous microemulsion but with orders of magnitude lower length scales. 7,8 Our first thermorheological studies in a wide temperature range of the two ILs with inorganic anions (Scheme 1, [Bmim]BF 4 and [TMP]Tos) revealed that both ILs are characterized by broad multimodal spectra of relaxation times and show cooperative dynamics and structural heterogeneity. 9 However, the degree of this structuration depends strongly on the molecular structure of the ILs and the strength and types of interand intra-ion interactions. Present research has been undertaken to explore the effect of azolate anion structure on the physical properties of ILs, specifically on their glassy dynamics and ion interactions, utilizing rheology, X-ray scattering, UV/vis absorption, and ab initio calculations. We have studied four ILs (Scheme 1), three of which shared the same 1-butyl-3-methylimidazolium ([Bmim]) cation. Figure 1 shows a T g -scaled Arrhenius representation of IL viscosities. (Here we use calorimetric glass-transition temperature T g .) The viscosity growth spans over 12 decades in the studied broad temperature range up to T g . The [Bmim]5AT exhibits higher viscosities in comparison with the other three ILs in the accessed temperature range. Note that the experimental viscosity of [Bmim]5AT at room temperature is η exp = 5 Pa 3 s, which exceeds the η-value calculated from ion dimensions (COSMO program) by an order of magnitude η cal = 0.45 Pa 3 s (table, Supporting Information). This indicates strong interactions between ions and possible structuration of [Bmim]5AT. ABSTRACT:We present studies of molecular dynamics and interactions in azolium azolate energetic ionic liquids (ILs) by utilizing a variety of physical methods. We observe peculiar rheological behavior for these ILs, which deviates from the one expected for molecular glass-formers. Major peculiarities include high elasticity in the low-frequency zone, peculiar van Gurp plots, and...

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confidence: 66%

Peculiar Behavior of Azolium Azolate Energetic Ionic Liquids

Pogodina

Metwalli

Müller‐Buschbaum

et al. 2011

J. Phys. Chem. Lett.

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“…Such pores can be described from the ellipsometric point of view as the so‐called “void material” with n = 1.00. Recently, we have shown on track etched polyimide films that this approach works well for the calculation of the fraction of nanovoids in a polyimide film 22. The ellipsometry results on the hyperbranched systems are summarised in Table 1.…”

Section: Resultsmentioning

confidence: 95%

Characterisation of Thin Composite Films from Hyperbranched Polyphenylene and Thermolabile Hyperbranched Polycarbonate

Stumpe¹,

Eichhorn²,

Voit³

2008

Macro Chemistry & Physics

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Thin composite films made from a thermally stable hyperbranched polyphenylene and a thermolabile hyperbranched polycarbonate were prepared on silicon wafers and characterised. The end groups of the polycarbonate were varied in order to accomplish an optimised interaction between the two components and thus the formation of homogeneous blends. The composite films were annealed at 200 °C in order to decompose the hyperbranched polycarbonate which can act as a porogen. The composition of the films before and after the annealing process was investigated applying IR spectroscopy and spectroscopic ellipsometry. Analysis of the data allowed calculating the volume fractions of the two materials within the films.

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“…Polyimide membranes are used as a starting material for a sample preparation based on the high energy of ion irradiation. As a result, the pore size in the membrane was an average of 73 nm and the pore shape was conical [24]. However, some problems of these methods are the complications and the high-cost of the process.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ionic Radius in Metal Nitrate on Pore Generation of Cellulose Acetate in Polymer Nanocomposite

2020

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To prepare a porous cellulose acetate (CA) for application as a battery separator, Cd(NO 3 ) 2 ·4H 2 O was utilized with water-pressure as an external physical force. When the CA was complexed with Cd(NO 3 ) 2 ·4H 2 O and exposed to external water-pressure, the water-flux through the CA was observed, indicating the generation of pores in the polymer. Furthermore, as the hydraulic pressure increased, the water-flux increased proportionally, indicating the possibility of control for the porosity and pore size. Surprisingly, the value above 250 LMH (L/m 2 h) observed at the ratio of 1:0.35 (mole ratio of CA: Cd(NO 3 ) 2 ·4H 2 O) was of higher flux than those of CA/other metal nitrate salts (Ni(NO 3 ) 2 and Mg(NO 3 ) 2 ) complexes. The higher value indicated that the larger and abundant pores were generated in the cellulose acetate at the same water-pressure. Thus, it could be thought that the Cd(NO 3 ) 2 ·4H 2 O salt played a role as a stronger plasticizer than the other metal nitrate salts such as Ni(NO 3 ) 2 and Mg(NO 3 ) 2 . These results were attributable to the fact that the atomic radius and ionic radius of the Cd were largest among the three elements, resulting in the relatively larger Cd of the Cd(NO 3 ) 2 that could easily be dissociated into cations and NO 3 − ions. As a result, the free NO 3 − ions could be readily hydrated with water molecules, causing the plasticization effect on the chains of cellulose acetate. The coordinative interactions between the CA and Cd(NO 3 ) 2 ·4H 2 O were investigated by IR spectroscopy. The change of ionic species in Cd(NO 3 ) 2 ·4H 2 O was analyzed by Raman spectroscopy.Polymers 2020, 12, 981 8 of 9 Polymers 2020, 12, x FOR PEER REVIEW 8 of 9 Scheme 1. Comparison of pore generation by species of metal salts in cellulose acetate.

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Supported Particle Track Etched Polyimide Membranes: A Grazing Incidence Small-Angle X-ray Scattering Study

Cited by 6 publications

References 34 publications

Peculiar Behavior of Azolium Azolate Energetic Ionic Liquids

Peculiar Behavior of Azolium Azolate Energetic Ionic Liquids

Characterisation of Thin Composite Films from Hyperbranched Polyphenylene and Thermolabile Hyperbranched Polycarbonate

Effect of Ionic Radius in Metal Nitrate on Pore Generation of Cellulose Acetate in Polymer Nanocomposite

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