scholarly journals Enhancement of Planar Orientation of Reactive Mesogen Molecules for Optical Retarder Film by Anisotropic Surface Plasma Treatment

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1080
Author(s):  
Jiyeon Kim ◽  
Ji-Hoon Lee
Keyword(s):  
Plasma Treatment ◽  
Azimuthal Angle ◽  
Anisotropic Plasma ◽  
Surface Plasma ◽  
Hydrophobic Property ◽  
Alignment Layer ◽  
Force Microscopy ◽  
Anisotropic Surface ◽  
Ceramic Electrodes ◽  
Planar Orientation

We proposed a method for enhancing the planar orientation of reactive mesogen (RM) molecules by means of anisotropic plasma treatment. Anisotropic surface plasma, of which energy density is dependent on the azimuthal angle, was generated by column-shaped ceramic electrodes. The anisotropic plasma was discharged on the surface of a polyvinyl alcohol (PVA) alignment layer before the rubbing process began. The contact angle of the surface was increased from 12° to 83° after plasma treatment, indicating a hydrophobic property of the surface. From the atomic force microscopy (AFM) measurement, it was found that the grain size of the PVA layer was reduced and that the grooved patterns were formed provided that the plasma direction was parallel to the rubbing direction of the surface. Consequently, the planar orientation was enhanced, and the in-plane retardation of the photo-polymerized RM films increased when the parallel plasma was treated on the surface.

scholarly journals Polyimide Surface Modification Using He-H2O Atmospheric Pressure Plasma Jet-Discharge Power Effect

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 662
Author(s):  
Essam Abdel–Fattah ◽  
Mazen Alshaer
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Discharge Power ◽  
Force Microscopy ◽  
Before And After ◽  
Power Effect

The atmospheric pressure He- H 2 O plasma jet has been analyzed and its effects on the Kapton polyimide surface have been investigated in terms of discharge power effect. The polyimide surfaces before and after plasma treatment were characterized using atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS) and contact angle. The results showed that, increasing the discharge power induces remarkable changes on the emission intensity, rotational and vibrational temperatures of He- H 2 O plasma jet. At the low discharge power ≤5.2 W, the contact angle analysis of the polyimide surface remarkably decrease owing to the abundant hydrophilic polar C=O and N–C=O groups as well as increase of surface roughness. Yet, plasma treatment at high discharge power ≥5.2 W results in a slight decrease of the surface wettability together with a reduction in the surface roughness and polar groups concentrations.

Repairing of Etching-Induced Damage of High-kBa0.5Sr0.5TiO3Thin Films by Oxygen Surface Plasma Treatment

2006 ◽  
Vol 45 (6B) ◽  
pp. 5490-5494 ◽  
Author(s):  
Kou-Chiang Tsai ◽  
Wen-Fa Wu ◽  
Chuen-Guang Chao ◽  
Jain-Tsai Lee ◽  
Jwo-Lun Hsu
Keyword(s):  
Plasma Treatment ◽  
Surface Plasma ◽  
Oxygen Surface

Millimeter-Wave Power AlGaN/GaN HEMT Using Surface Plasma Treatment of Access Region

2017 ◽  
Vol 64 (12) ◽  
pp. 4875-4881 ◽  
Author(s):  
Minhan Mi ◽  
Xiao-Hua Ma ◽  
Ling Yang ◽  
Yang Lu ◽  
Bin Hou ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Millimeter Wave ◽  
Wave Power ◽  
Surface Plasma ◽  
Gan Hemt

scholarly journals Biomimetic nanostructures for the silicone-biosystem interface: tuning oxygen-plasma treatments of polydimethylsiloxane

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Bekim Osmani ◽  
Gabriela Gerganova ◽  
Bert Müller
Keyword(s):  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Oxygen Plasma Treatment ◽  
Pdms Film ◽  
Pdms Surface ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Hydrophobic Recovery

AbstractPolydimethylsiloxanes (PDMS) have drawn attention because of their applicability in medical implants, soft robotics and microfluidic devices. This article examines the formation of dedicated nanostructures on liquid submicrometer PDMS films when exposed to oxygen-plasma treatment. We show that by using a vinyl-terminated PDMS prepolymer with a molecular weight of 800 g/mol, one can bypass the need of solvent, copolymer, or catalyst to fabricate wrinkled films. The amplitude and periodicity of the wrinkles is tuned varying the thickness of the PDMS film between 150 and 600 nm. The duration of the plasma treatment and the oxygen pressure determine the surface morphology. The amplitude was found between 30 and 300 nm with periodicities ranging from 500 to 2800 nm. Atomic force microscopy was used to measure film thickness, amplitude and wrinkle periodicity. The hydrophobic recovery of the nanostructured PDMS surface, as assessed by dynamic contact angle measurements, scales with nanostructure’s fineness, associated with an improved biocompatibility. The mechanical properties were extracted out of 10,000 nanoindentations on 50×50-μm

Surface Plasma Treatment of Polyimide Film for Cu Metallization

2011 ◽  
Vol 50 (1S1) ◽  
pp. 01AK02 ◽  
Author(s):  
Sang-Jin Cho ◽  
Jin-Woo Choi ◽  
In-Seob Bae ◽  
Trieu Nguyen ◽  
Jin-Hyo Boo
Keyword(s):  
Plasma Treatment ◽  
Polyimide Film ◽  
Surface Plasma ◽  
Cu Metallization

Adhesion improvement of high modulus polyethylene fibers by surface plasma treatment: Evaluation by pull-out testing

1994 ◽  
Vol 15 (3) ◽  
pp. 247-251 ◽  
Author(s):  
P. Masse ◽  
J. P. Cavrot ◽  
P. François ◽  
J. M. Lefebvre ◽  
B. Escaig
Keyword(s):  
Plasma Treatment ◽  
Treatment Evaluation ◽  
High Modulus ◽  
Surface Plasma ◽  
Pull Out ◽  
Modulus Polyethylene ◽  
Polyethylene Fibers

Mechanism of hole inlet closure in shape transformation of hole arrays on Si(001) substrates by hydrogen annealing

2011 ◽  
Vol 1299 ◽  
Author(s):  
Reiko Hiruta ◽  
Hitoshi Kuribayashi ◽  
Koichi Sudoh ◽  
Ryosuke Shimizu
Keyword(s):  
Surface Diffusion ◽  
Mirror Symmetry ◽  
Morphological Evolution ◽  
Shape Transformation ◽  
Force Microscopy ◽  
Anisotropic Surface ◽  
Atomic Force ◽  
Hole Arrays ◽  
Top View ◽  
Anisotropic Surface Energy

ABSTRACTWe investigated the process of the hole inlet closure in surface-diffusion-driven transformation of arrays of high-aspect-ratio holes on Si(001) substrates. The inlet gradually shrinks while keeping the circular shape because of lateral bulging of the inlet surface. We observed complicated top view morphologies reflecting the four-fold symmetry of the Si(001) surface on the inlet surface. Large {111} and {113} facets are formed in the four equivalent azimuths of the [110], while corrugated patterns arise in the four equivalent azimuths of the [100]. Atomic force microscopy observations reveal that the corrugated pattern is composed of three types of small facets, namely, {110} and two {113} in relation of the mirror symmetry. The corrugated pattern formation is due to the geometrical restriction that there is no stable facet between (001) and (010) in the [010] azimuth. The observed morphological evolution is interpreted as surface-diffusion-driven transformation under constraint of the anisotropic surface energy of Si.

scholarly journals New Strategy for Inducing Surface Anisotropy in Polyimide Films for Nematics Orientation in Display Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3107
Author(s):  
Elena-Luiza Epure ◽  
Iuliana Stoica ◽  
Raluca Marinica Albu ◽  
Camelia Hulubei ◽  
Andreea Irina Barzic
Keyword(s):  
Liquid Crystals ◽  
Surface Anisotropy ◽  
Polyimide Films ◽  
Alignment Layer ◽  
Display Devices ◽  
Force Microscopy ◽  
Atomic Force ◽  
New Strategy ◽  
Great Relevance ◽  
Novel Strategy

The operability of liquid crystal displays is strongly impacted by the orientation aspects of nematics, which in turn are affected by the alignment layer surface features. In this work, two polyimide (PI) structures are obtained based on a cycloaliphatic dianhydride and aromatic or aliphatic diamines with distinct flexibility. The attained PI films have high transmittance (T) for visible radiations, i.e., at 550 nm T > 80%. Here, a novel strategy for creating surface anisotropy in the samples that combines rubbing with a cloth and stretching via pressing is reported. Birefringence and atomic force microscopy (AFM) scans reveal that the generated orientation of the chains is affected by the chemical structure of the polymer and order of the steps involved in the surface treatment. Molecular modeling computations and wettability tests show that the PI structure and produced surface topography are competitive factors, which are impacting the intensity of the interactions with the nematic liquid crystals. The achieved results are of great relevance for designing of reliable display devices with improved uniform orientation of liquid crystals.

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