External Electric Field Assisted Ultraviolet Irradiation for Bonding of Lubricant Film on Magnetic Disks

Tani, Hiroshi; Sakane, Yasuo; Koganezawa, Shinji; Tagawa, Norio

doi:10.1109/tmag.2014.2318015

Cited by 3 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, it has been reported extensively in the past 25 years that UV will induce covalent bonding between PFPEs and solid substrates. − It is beyond the scope of the current paper to comprehensively review the previous results on this topic. Here we only briefly discussed the key findings.…”

Section: Resultsmentioning

confidence: 99%

Fabricating Nanometer-Thick Simultaneously Oleophobic/Hydrophilic Polymer Coatings via a Photochemical Approach

et al. 2016

View full text Add to dashboard Cite

The simultaneously oleophobic/hydrophilic coatings are highly desirable in antifogging, oil-water separation, and detergent-free cleaning. However, such coatings require special chemical structure, i.e., perfluorinated backbone and polar end-groups, and are too expensive for real-life application. Here, we have developed an UV-based photochemical approach to make nanometer-thick perfluoropolyethers without polar end-groups, which are not intrinsically simultaneously oleophobic/hydrophilic but cost-effective, become simultaneously oleophobic/hydrophilic. The contact angle, ellipsometry, and X-ray photoelectron spectroscopy (XPS) results indicated that the UV irradiation results in the covalent bonding between the polymer and the substrate, which renders more ordered packing of polymer chains and thus the appropriately small interchain distance. As a result, the small water molecules penetrate the polymer network while large oil molecules do not. As a result, the oil contact angle is larger than the water contact angle and the coating shows the simultaneous oleophobicity/hydrophilicity. Moreover, we also demonstrated that this nanometer-thick simultaneously oleophobic/hydrophilic coating has improved long-term antifogging performance and detergent-free cleaning capability and is mechanically robust. The photochemical approach established here potentially can be applied on many other polymers and greatly accelerate the development and application of simultaneously oleophobic/hydrophilic coatings.

show abstract

Section: Resultsmentioning

confidence: 99%

Fabricating Nanometer-Thick Simultaneously Oleophobic/Hydrophilic Polymer Coatings via a Photochemical Approach

et al. 2016

View full text Add to dashboard Cite

show abstract

“…1 [9]. Using a high-voltage power supply, an electric field is applied between the disk surface and the electrode against the disk surface.…”

Section: Photoelectron-assisted Uv Irradiation Processmentioning

confidence: 99%

“…The experimental setup is shown in Fig. 2 [9]. UV light was irradiated through a quartz window and a grid electrode onto the disk surface.…”

Section: Photoelectron-assisted Uv Irradiation Processmentioning

confidence: 99%

“…16. Since the trifluoromethyl-phenoxy function of the cyclo-triphosphazene end groups is easily dissociated by photoelectron capture [9], it is estimated that the end group decomposes sequentially, as shown in Fig. 16.…”

Section: Tof-sims Analysismentioning

confidence: 99%

“…If the duration of UV irradiation is long to increase the chemical-bonded lubricant, the directly dissociation of lubricant molecules is increased and the friction property might be degraded. Then, we have developed the photoelectron-assisted UV irradiation process [9], which involves UV irradiation of the disk surface with a bias voltage, to obtain more highly chemically bonded lubricant films than the normal UV process. Because the bias voltage to the disk surface increases photoelectron emission due to UV irradiation, the number of emitted photoelectrons is more than that of normal UV process.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improvement in Heat Resistance of Perfluoropolyether Lubricant Films on Magnetic Disks by UV Irradiation with a Bias Voltage on the Disk Surface

et al. 2016

View full text Add to dashboard Cite

Our previous study confirmed that the photoelectron-assisted ultraviolet (UV) irradiation with a bias voltage between the magnetic disk and the counter electrode above the disk surface increased the bonded ratio of a perfluoropolyether lubricant film on the disk surface. In this study, two types of lubricant materials (Fomblin Z-tetraol and Moresco ADOH) were prepared and coated on disks. After coating the lubricant films, UV irradiation of the lubricated disk surface was performed using the normal process and the photoelectron-assisted process, and the depletions of these lubricant films were compared using the pin-on-disk test with the laser heating function. The results showed that the lubricant film treated with normal UV irradiation without the bias voltage showed a deeper depletion of the lubricant film than that treated with photoelectron-assisted UV irradiation, and the ADOH film showed a shallower depletion than the Z-tetraol film. However, the molecular weight distributions of the ADOH films on DLC surfaces treated by UV irradiation were compared using time-of-flight secondary ion mass spectroscopy, and the film treated with photoelectron-assisted UV irradiation did not change owing to dissociation after photoelectron capture. Photoelectron-assisted UV irradiation led to the decomposition of the cyclo-triphosphazene end groups. Therefore, it is assumed that the depletion of lubricant films treated with photoelectron-assisted UV irradiation was reduced, since the bonding strength to the DLC surface increased because of the greater decomposition of end groups.

show abstract

Ultrathin PFPE/DLC hybrid overcoat for magnetic disks by photoelectron-assisted chemical vapor deposition

Tani

Rengo

Koganezawa

et al. 2016

2016 Asia-Pacific Magnetic Recording Conference Digest (APMRC)

View full text Add to dashboard Cite

External Electric Field Assisted Ultraviolet Irradiation for Bonding of Lubricant Film on Magnetic Disks

Cited by 3 publications

References 7 publications

Fabricating Nanometer-Thick Simultaneously Oleophobic/Hydrophilic Polymer Coatings via a Photochemical Approach

Fabricating Nanometer-Thick Simultaneously Oleophobic/Hydrophilic Polymer Coatings via a Photochemical Approach

Improvement in Heat Resistance of Perfluoropolyether Lubricant Films on Magnetic Disks by UV Irradiation with a Bias Voltage on the Disk Surface

Ultrathin PFPE/DLC hybrid overcoat for magnetic disks by photoelectron-assisted chemical vapor deposition

Contact Info

Product

Resources

About