Molecular Design of Durable Hydrophobic Film

Author(s):  
Kum Hwan Cha ◽  
Stephen M. Hsu

The demand for long durable hydrophobic surface is rising as more and more devices are coming to market. Nanotechnology promises more micro- and nanoscale devices for biomedical, aerospace, transportation purposes. Hydrophobicity can be imparted by a thin layer of low surface energy molecules or a densely-packed hydrocarbon film. Because of heterogeneous surface energy and surface defects, very few films can stay defect-free for an appreciate period of time. Eventually, moisture penetrates into the film through pin holes or defects created by surface reconfiguration. This paper describes a novel hydrophobic film design combining geometric stacking concept with self-healing mobile molecules and an polymeric canopy of cross-linking top layer to prevent evaporation of organic molecules, all within two nanometer thick suitable for most micro- and nanodevices applications.

2002 ◽  
Vol 12 (6) ◽  
pp. 1684-1692 ◽  
Author(s):  
Luisa Andruzzi ◽  
Emo Chiellini ◽  
Giancarlo Galli ◽  
Xuefa Li ◽  
Seok H. Kang ◽  
...  

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.


Polymer ◽  
2021 ◽  
Vol 217 ◽  
pp. 123481
Author(s):  
Zhanhui Gan ◽  
Deyu Kong ◽  
Qianqian Yu ◽  
Yifan Jia ◽  
Xue-Hui Dong ◽  
...  

Author(s):  
Mohamed R. Rizk ◽  
Muhammad G. Gamal ◽  
Amina Mazhar ◽  
Mohamed El-Deab ◽  
Bahgat El-Anadouli

In this work, we report a single-step preparation of porous Ni-based foams thin layer atop Cu substrate via a facile dynamic hydrogen bubble template technique (DHBT). The prepared porous Ni-based...


AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035219
Author(s):  
Ya-Kun Lyu ◽  
Zuo-Tao Ji ◽  
Tao He ◽  
Zhenda Lu ◽  
Weihua Zhang

2004 ◽  
Vol 37 (2) ◽  
pp. 408-413 ◽  
Author(s):  
L. van Ravenstein ◽  
W. Ming ◽  
R. D. van de Grampel ◽  
R. van der Linde ◽  
G. de With ◽  
...  

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