Characterization of polyimide Langmuir-Blodgett films on silver using infrared, Raman and x-ray photoelectron spectroscopies

Zhao, Wu; Boerio, F. J.

doi:10.1002/(sici)1096-9918(199804)26:4<316::aid-sia370>3.0.co;2-5

Cited by 12 publications

(6 citation statements)

References 6 publications

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“…In addition, a surplus has to be added, which compensates for the positive charge of the template molecules. The protonation of the amine has been proved by XPS investigations of C 16 −VO x −NTs and C 20 −VO x −NTs: the N(1s) core level energy (401.5 and 401.6 eV) of the cation is higher than that of unprotonated alkylamine (399.6 and 399.3 eV) and corresponds to a positively charged nitrogen . Independently, cation exchange reactions on C 12 −VO x −NTs and C 16 −VO x −NTs show that between 70 and 90% of the template can be exchanged by different cations (see below and ref ).…”

Section: Resultsmentioning

confidence: 94%

Morphology and Topochemical Reactions of Novel Vanadium Oxide Nanotubes

et al. 1999

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Vanadium oxide nanotubes were obtained as the main product in a sol−gel reaction followed by hydrothermal treatment from vanadium(V) alkoxide precursors and primary amines (C n H2 n +1NH2 with 4 ≤ n ≤ 22) or α,ω-diamines (H2N[CH2] n NH2 with 14 ≤ n ≤ 20). The structure of the nanotubes has been characterized by transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and magnetic measurements. The tubes are up to 15 μm long and have outer diameters ranging from 15 to 150 nm and inner diameters from 5 to 50 nm. The tube walls consist of 2−30 crystalline vanadium oxide layers with amine or diamine molecules intercalated in between. The distance between the layers (1.7−3.8 nm) is proportional to the length of the alkylamine, which acts as a structure-directing template. The structure within the layers has a square metric with a ≈ 0.61 nm. Cross-sectional TEM images demonstrate the predominance of serpentine-like scrolls rather than of concentric tubes. The intercalated templates can be easily substituted, e.g. by diamines, while the tubular morphology is preserved. This points to a highly flexible structure.

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Section: Resultsmentioning

confidence: 94%

Morphology and Topochemical Reactions of Novel Vanadium Oxide Nanotubes

et al. 1999

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“…The absorption peak at 1720 cm -1 attributed to the vibrational modes of the carboxylic acid and the bands at 1660 and 1543 cm -1 corresponding to the vibrational mode of the amide group are diagnostic of the amic acid. , However, slight differences were observed in the range of 2700−3100 cm -1 . Two absorption peaks were present at 2910 and 2840 cm -1 , which were assigned to ν a (CH 2 ) and ν s (CH 2 ) of the hydrocarbon chains, respectively 8 ATR-FTIR spectra recorded for the upside and underside of the pure damp−dry poly(amic acid) films kept in an ambient environment for (A) 3 days and (B) 9 days.…”

Section: Resultsmentioning

confidence: 99%

“…Two absorption peaks were present at 2910 and 2840 cm -1 , which were assigned to ν a (CH 2 ) and ν s (CH 2 ) of the hydrocarbon chains, respectively. 42 As can be seen from the A-U and A-D spectra in Figure 8, the intensity of the absorbance bands for the upside is much lower than that for the underside upon keeping the PAA films at ambient temperature for 3 days. After drying the films for 9 days, the intensity of the bands for the upside almost disappeared, while the intensity of the bands for the underside analogues did not show any distinct changes.…”

Section: Surface Structural Variationsmentioning

confidence: 93%

Highly Reflective and Conductive Double-Surface-Silvered Polyimide Films Prepared from Silver Fluoride and BTDA/4,4‘-ODA

et al. 2007

Langmuir

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This work focuses on surface silver metallization on a 3,3',4,4'-benzophenonetetracarboxylic dianhydride/4,4'-oxydianiline (BTDA/ODA)-based polyimide matrix via a direct ion-exchange self-metallization technique using a simple silver salt, silver fluoride, as the silver precursor. The method involves performing an ion-exchange reaction of damp-dry poly(amic acid) films in silver aqueous solution to form silver(I)-containing precursor films. Thermal treatment under tension converts the poly(amic acid) into polyimide and simultaneously reduces the silver(I) to silver(0), yielding silver layers with excellent reflectivity and conductivity on both film sides. However, significant property differences were exhibited on the upside and underside surfaces of the metallized films and this has been discussed in detail. The variation of surface properties and surface morphologies during the thermal curing cycle was also investigated. The mechanical and thermal properties of the metallized polyimide films are essentially similar to those of the host polyimide.

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“…A considerable amount of research into the thermal imidization of poly(4,4‘-oxydiphenylene pyromellitamic acid) (PMDA-4,4‘-ODA PAA) has been carried out. − In comparison, research into its PAE precursor, poly(4,4‘-oxydiphenylene pyromellitamic diethyl ester) (PMDA-4,4‘-ODA PAE), has been limited. Kramer and co-workers − measured the extent of imidization as a function of depth in films of deuterated PMDA-4,4‘-ODA PAE using ion beam analysis techniques.…”

Section: Introductionmentioning

confidence: 99%

Thermal Imidization and Structural Evolution of Thin Films of Poly(4,4‘-oxydiphenylene p-pyromellitamic diethyl ester)

Shin

Ree

2007

J. Phys. Chem. B

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The evolution of chemical composition and structure during the thermal imidization of an ester-type polyimide precursor, poly(4,4'-oxydiphenylene p-pyromellitamic diethyl ester), in micrometer scale films were studied for a heating rate of 2.0 degrees C/min with time-resolved synchrotron X-ray diffraction, in-situ infrared spectroscopy, and modulated differential scanning calorimetry. Our analyses show that the precursor polymer undergoes imidization in a two-step process. In the first step, the precursor polymer is decomplexed from the residual solvent molecules, and in the second step, it undergoes imide ring formation with the release of ethanol as a byproduct. The imidization reaction starts around 210 degrees C and continues up to 320 degrees C. The thermal imidization reaction induces the structural evolution of the film. As the imidization reaction proceeds, the coherent length along the polymer chain axis increases. This imidization-induced structural evolution was found to occur via three steps: (i) initiation, (ii) the first crystallization, and (iii) the second crystallization. The initiation step is necessary prior to the evolution of the crystalline structure to increase the chain mobility of the precursor polymer chains, and it requires thermal heating up to at least 238 degrees C at which point 22.5% of the imidization is complete. Thereafter, the first crystallization occurs up to 310 degrees C, at which point 98.3% of the imidization is complete. In the range 310-380 degrees C, the second crystallization occurs and produces almost complete imidization of the polymer chains.

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Characterization of polyimide Langmuir-Blodgett films on silver using infrared, Raman and x-ray photoelectron spectroscopies

Cited by 12 publications

References 6 publications

Morphology and Topochemical Reactions of Novel Vanadium Oxide Nanotubes

Morphology and Topochemical Reactions of Novel Vanadium Oxide Nanotubes

Highly Reflective and Conductive Double-Surface-Silvered Polyimide Films Prepared from Silver Fluoride and BTDA/4,4‘-ODA

Thermal Imidization and Structural Evolution of Thin Films of Poly(4,4‘-oxydiphenylene p-pyromellitamic diethyl ester)

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