Semi-Alicyclic Polyimides: Insights into Optical Properties and Morphology Patterning Approaches for Advanced Technologies

Barzic, Andreea Irina; Stoica, Iuliana; Hulubei, Camelia

doi:10.5772/53607

Cited by 2 publications

(2 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wrinkle wavelength is independent of the diameter of the bacteria, since (a) the wrinkle wavelength is a consequence of the balance of graphene's bending energy and the bacterium's contraction energy, both of which are relatively unaffected by the bacterial diameter, and (b) the bacterial curvature is significantly smaller than the wrinkle curvature (D bacteria /λ wrinkle = 20−35) to have a significant geometric effect on the wrinkle wavelength (as shown in Supporting Figure S3). The angular image analysis depicts 23 that the texture direction (TD) of the selected wrinkle area is 89.7 ± 0.6°(close to 90°) (Figure 2b), implying longitudinal directionality of wrinkles. Further, a surface with a texture aspect ratio (TAR) of 0.125 (<0.3) (Figure 2c) for the wrinkled graphene indicates strong spatial anisotropy.…”

Section: Resultsmentioning

confidence: 93%

Confined, Oriented, and Electrically Anisotropic Graphene Wrinkles on Bacteria

et al. 2016

View full text Add to dashboard Cite

Curvature-induced dipole moment and orbital rehybridization in graphene wrinkles modify its electrical properties and induces transport anisotropy. Current wrinkling processes are based on contraction of the entire substrate and do not produce confined or directed wrinkles. Here we show that selective desiccation of a bacterium under impermeable and flexible graphene via a flap-valve operation produces axially aligned graphene wrinkles of wavelength 32.4-34.3 nm, consistent with modified Föppl-von Kármán mechanics (confinement ∼0.7 × 4 μm(2)). Further, an electrophoretically oriented bacterial device with confined wrinkles aligned with van der Pauw electrodes was fabricated and exhibited an anisotropic transport barrier (ΔE = 1.69 meV). Theoretical models were developed to describe the wrinkle formation mechanism. The results obtained show bio-induced production of confined, well-oriented, and electrically anisotropic graphene wrinkles, which can be applied in electronics, bioelectromechanics, and strain patterning.

show abstract

Section: Resultsmentioning

confidence: 93%

Confined, Oriented, and Electrically Anisotropic Graphene Wrinkles on Bacteria

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Polyimides are well-known for their outstanding mechanical strength, heat resistance, and chemical stability and are utilized in the aerospace and electronic material fields [1]. Controlling the polyimide morphology is a worthwhile research endeavor to develop their applicability [2][3][4][5][6]. Porous polyimides have expected deployment as functional materials such as low-dielectric (low-k) materials and battery separators [7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Mesoporous Polyimide Composite Films by a Soft-Template Method Followed by Ozonolysis

Komamura

Azuma

Nabae

et al. 2020

J. Photopol. Sci. Technol.

View full text Add to dashboard Cite

Mesoporous polyimide composite films were fabricated by a soft template method using a microphase-separated structure of an amphiphilic block copolymer and porosification by ozonolysis. Poly(1,4-isoprene)-block-poly(2-vinylpyridine) was used as the template block copolymer. Poly(amic acid) (PAA), the precursor of polyimide, and resol, the cross-linker for stabilization of the nanostructure, were miscible into the poly(2-vinylpyridine) domain which is the hydrophilic domain of the template block copolymer. The mixture co-assembled and formed a periodic body-centered cubic nanostructure. The study of ozonolysis condition revealed that the reaction in hexane allowed porosification without the collapse of the nanostructure. Polyimide composite films with well-defined mesopores were successfully obtained by the sequential processes of the PAA composite film, namely, thermal annealing for crosslinking of resol, ozonolysis in hexane for the decomposition of polyisoprene domain, and thermal treatment for imidization of PAA. The domain spacing determined by smallangle X-ray scattering was 28.8 nm, and the average pore size based on scanning electron microscopy was 24 nm.

show abstract

Semi-Alicyclic Polyimides: Insights into Optical Properties and Morphology Patterning Approaches for Advanced Technologies

Cited by 2 publications

References 66 publications

Confined, Oriented, and Electrically Anisotropic Graphene Wrinkles on Bacteria

Confined, Oriented, and Electrically Anisotropic Graphene Wrinkles on Bacteria

Fabrication of Mesoporous Polyimide Composite Films by a Soft-Template Method Followed by Ozonolysis

Contact Info

Product

Resources

About