Preparation of Nanostructured Superhydrophobic Copper and Aluminum Surfaces

2011 ◽  
Vol 409 ◽  
pp. 497-501 ◽  
Author(s):  
Ying Huang ◽  
Dilip K. Sarkar ◽  
X. Grant Chen

Preparation of nanostructured superhydrophobic surfaces requires both an optimum roughness and low surface energy. Application of a direct voltage between two copper plates immersed in a dilute ethanolic stearic acid solution transforms the surface of the anodic copper electrode to superhydrophobic due to the formation of micro-nanofibrous low surface energy flower-like copper stearate as confirmed by scanning electron microscope (SEM). Nanostructured superhydrophobic aluminum surfaces have also been prepared by electrodeposition of copper films on aluminum surfaces followed by electrochemical modification by ethanolic stearic acid. The X-ray diffraction (XRD) analyses confirmed the formation of copper films on aluminum substrates. The electrodeposited copper films are composed of microdots of copper whose density increases with the decrease of deposition potential as observed by SEM. The deposited copper microdots on aluminum substrates were electrochemically modified to low surface energy copper stearate nanofibres to obtain superhydrophobicity. The copper films deposited at potentials above-0.6 V did not exhibit superhydrophobic properties. However, the copper films deposited at potential-0.6 V and below exhibited superhydrophobic properties with water drop rolling-off those surfaces.

2012 ◽  
Vol 258 (8) ◽  
pp. 4063-4068 ◽  
Author(s):  
Long Yin ◽  
Yuanyi Wang ◽  
Jianfu Ding ◽  
Qingjun Wang ◽  
Qingmin Chen

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 982
Author(s):  
Henry Agbe ◽  
Dilip Kumar Sarkar ◽  
X.-Grant Chen

Surfaces in a hygiene critical environment can become potential reservoirs for transmission of pathogenic infections. Engineering surfaces with the tunable anti-biofouling and antibacterial properties could reduce infections particularly in hospitals and public transport hubs. In the present work, a facile two-step process has been deployed to fabricate a superhydrophobic and antibacterial aluminum surface by chemical etching, followed by passivation with low surface energy octyltriethoxysilane (OTES) molecules. The wettability and antibacterial properties of the OTES passivated aluminum was monotonically tuned by adding quaternary ammonium (QUATs) molecules. An anti-biofouling property of 99.9% against Staphylococcus aureus, 99% against Pseudomonas aeruginosa and 99% against E. coli bacteria, was achieved.


2020 ◽  
Vol 15 (12) ◽  
pp. 1502-1507
Author(s):  
Yanhong Fang ◽  
Ping Wang ◽  
Lifang Sun ◽  
Linhong Wang

In this study, simple and feasible methods are used to increase the hydrophobicity of EP-POSS, that is, etching with concentrated hydrochloric acid and concentrated ammonia water, followed by modification with polytetrafluoroethylene and stearic acid. The principle of the study is to increase the hydrophobic angle of EP-POSS by immersion in concentrated hydrochloric acid and concentrated ammonia for a sufficiently long time, followed by modification with low-surface-energy materials, i.e., polytetrafluoroethylene and stearic acid. The contact angle of EP-POSS increased from 100° to 133° after immersing in 3 mol/L hydrochloric acid for 12 min. Compared to hydrochloric acid, the surface roughness and contact angel were not changed significantly by immersing in concentrated ammonia for 4 hours. The contact angle was not changed obviously after immersing in 0.1 mol/L polytetrafluoroethylene for 24 h, and only changed from 135° to 136° when immersed in 0.1 mol/L stearic acid. It shows that PTFE and stearic acid hasn?t effectively grafted to the surface of EP-POSS, and has no effect to the micro-nano structure of EP-POSS. According to the experimental results, hydrochloric acid etching is the proper way to enhance EP-POSS contact angel. According to further investigates, it can be determined that treating EP-POSS at 40 °C for 12 min with 3 mol/L hydrochloric acid can significantly improve its hydrophobicity, thus, the hydrophobic performance of EP-POSS is considerably improved.


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.


2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Violeta Vasilache ◽  
Gheorghe Gutt ◽  
Traian Vasilache

The electrochemical deposition of zinc and combinations with elements of the 8th group of the Periodic System (nickel, cobalt, iron) have good properties for anticorrosive protection, compared with pure zinc. For steel pieces, these films delay apparition and formation of white and red iron oxide. We used solutions with different concentrations of zinc chloride, nickel chloride and potassium chloride. To analyze the results we used the optic microscope and the X-ray diffraction.


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

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.


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

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 211
Author(s):  
Hongfeng Li ◽  
Xiangwen Lin ◽  
Hongguang Wang

In order to address water damage of asphalt pavement, reduce the occurrence of water-related potholes, deformation, and other diseases, and improve the performance and service life of the pavement, a nano-TiO2 superhydrophobic coating (PSC) on asphalt pavement was prepared from waterborne polyurethane and nano-TiO2 modified by stearic acid. FT-IR measured stearic acid successfully modified low surface energy substance on the surface of nano-TiO2. The SEM image shows that the PSC has a rough surface structure. The contact angle and rolling angle of the PSC in the contact angle test are 153.5° and 4.7°, respectively. PSC has a super-hydrophobic ability, which can improve the water stability of the asphalt mixture. Although the texture depth and pendulum value have been reduced by 2.5% and 4.4%, respectively, they all comply with the standard requirements. After the abrasion resistance test, the PSC coating still has a certain hydrophobic ability. These results surface PSC coating can effectively reduce water damage on asphalt pavement, and has considerable application value.


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