Self-assembly of nano-sized arrays on highly oriented thin films of poly(tetrafluoroethylene)

Tosaka, Masatoshi; Tsuji, Masaki; Ogawa, Teppei; Kitano, Hirofumi; Nakano, Kohtaro; Kohjiya, Shinzo; Danev, Radostin; Nagayama, Kuniaki

doi:10.1016/j.polymer.2005.12.044

Cited by 10 publications

(7 citation statements)

References 22 publications

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“…The ability of solid poly(tetrafluoroethylene) (PTFE) to promote crystal growth of other species is well known, and was most conspicuously demonstrated in earlier work, in which friction‐deposited, highly oriented layers of this polymer were shown to induce oriented crystallization of a most unusual, broad spectrum of materials, including biological species and inorganic and organic compounds, as well as a variety of polymers 1–6. Although this technique may be academically interesting and of potential relevance for creating oriented thin layers for use in, for instance, opto‐electronic components,7 it evidently would not appear practical to employ this approach to enhance nucleation of semi‐crystalline bulk polymers, commonly applied to reduce processing cycles, achieve better control of the nucleation density, or beneficially alter their solid‐state structure to improve mechanical or optical properties (e.g.,8–12).…”

Section: Introductionmentioning

confidence: 99%

Nucleating polymer crystallization with poly(tetrafluoroethylene) nanofibrils

Bernland¹,

Smith²

2009

J of Applied Polymer Sci

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The ability of nanofibrils of poly(tetrafluoroethylene) (PTFE) -in situ generated during compounding -to efficiently nucleate crystal growth of the bulk polymers isotactic polypropylene (i-PP), high-density polyethylene (HDPE), polyoxymethylene (POM), polyamide 12 (PA12) and poly(ethylene therephthalate) (PET) is demonstrated. Enhanced nucleation is shown to occur already at PTFE contents as low as 0.001% w/w in i-PP and HDPE. In addition it was found that compounding with PTFE lead to improved clarity of the latter polymers.

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Section: Introductionmentioning

confidence: 99%

Nucleating polymer crystallization with poly(tetrafluoroethylene) nanofibrils

Bernland¹,

Smith²

2009

J of Applied Polymer Sci

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“…The details of these instruments and the principles of the phase contrast TEM have been described elsewhere. , It is possible to obtain a realistic image without suffering from the influences of chemical fixation, dehydration, staining, and vapor deposition by this method. Therefore, it is a very powerful method for acquiring micro- and nanostructural information, not only on biological samples but also on chemical materials, especially soft matter. − …”

Section: Introductionmentioning

confidence: 99%

“…Therefore, it is a very powerful method for acquiring micro-and nanostructural information, not only on biological samples but also on chemical materials, especially soft matter. [21][22][23][24] Experimental Section Materials. N-Hexadecanoyl, N-tetradecanoyl, and N-dodecanoyl L-phenylalanines (Cn-L-Phe: n ) 16, 14, and 12) were synthesized by the reaction of L-phenylalanine with each acyl chloride as described previously 25 and were recrystallized from their mixtures in acetonemethanol at least three times.…”

Section: Introductionmentioning

confidence: 99%

Transition from Nanotubes to Micelles with Increasing Concentration in Dilute Aqueous Solution of Potassium N-Acyl Phenylalaninate

et al. 2006

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An aggregation behavior of potassium N-acyl phenylalaninate in dilute aqueous solution was investigated. It was found that this surfactant formed large aggregates at lower concentrations, which were then transformed to micelles at higher concentrations. Fluorescence intensity measurements using a probe were used to examine the effects of alkali concentration, acyl chain length, and solvent isotope on the aggregation behavior. The influence of the alkali concentration suggested that formation of an acid-soap dimer brought about the construction of the large particles at very dilute concentrations. Increases in both the acyl chain length and replacement of H(2)O with D(2)O resulted in stronger hydrophobic interactions; consequently, the large aggregate formation was enhanced. This aggregation behavior has not been observed when racemic modification of N-acyl phenylalaninate has taken place. By using cryo-transmission electron microscopy (TEM) with a Zernike differential contrast phase plate, it was found that the large aggregates were tubes with bilayer structures, which were then transformed into spherical micelles via threadlike micelles with increasing concentration due to a drastic increase in the concentration of ionic species in the aggregate.

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“…Recently a new push in the application of thin film phase plates in Transmission Electron Microscopy (TEM) was initiated 1 – 12 . Observation of weak biological specimens is improved by the higher contrast and wider information transfer of the phase plate techniques.…”

mentioning

confidence: 99%

“…Currently the development is focused on two such techniques employing two different kinds of phase plates. One utilizes a π/2 Zernike phase plate positioned at the back focal plane of the objective lens 2 , 3 , 6 , 10 , 12 . The other uses a π half-plane phase plate also positioned at the diffraction plane 5 , 6 , 7 , 9 , 11 .…”

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confidence: 99%

Applicability of thin film phase plates in biological electron microscopy

Danev

Nagayama

2006

BIOPHYSICS

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Presented is an evaluation of phase contrast techniques in transmission electron microscopy. The traditional defocus phase contrast is compared to two recently developed phase plate techniques. One is the Zernike phase contrast transmission electron microscope, the other is the Hilbert differential contrast thransmission electron microscope. The imaging characteristics of each technique are discussed. Phase plate techniques provide improved contrast for ice-embedded biological samples which are a challenge for the conventional defocus phase contrast. The flat spectral response of the Zernike and Hilbert modes extends towards the low frequencies which are severely suppressed in the conventional defocus mode. Target applications for each of the phase contrast techniques are discussed based on the specifics of image formation and spectral transfer.

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Self-assembly of nano-sized arrays on highly oriented thin films of poly(tetrafluoroethylene)

Cited by 10 publications

References 22 publications

Nucleating polymer crystallization with poly(tetrafluoroethylene) nanofibrils

Nucleating polymer crystallization with poly(tetrafluoroethylene) nanofibrils

Transition from Nanotubes to Micelles with Increasing Concentration in Dilute Aqueous Solution of Potassium N-Acyl Phenylalaninate

Applicability of thin film phase plates in biological electron microscopy

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