scholarly journals Nonthermal Plasma Treatment Improves Uniformity and Adherence of Cyclodextrin-Based Coatings on Hydrophobic Polymer Substrates

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1056
Author(s):  
Greg D. Learn ◽  
Emerson J. Lai ◽  
Horst A. von Recum

Low surface energy substrates, which include many plastics and polymers, present challenges toward achieving uniform, adherent coatings, thus limiting intended coating function. These inert materials are common in various applications due to favorable bulk, despite suboptimal surface, properties. The ability to functionally coat low surface energy substrates holds broad value for uses across medicine and industry. Cyclodextrin-based materials represent an emerging, widely useful class of coatings, which have previously been explored for numerous purposes involving sustained release, enhanced sorption, and reversible reuse thereof. In this study, substrate exposure to nonthermal plasma was explored as a novel means to improve uniformity and adherence of cyclodextrin-based polyurethane coatings upon unreceptive polypropylene substrates. Plasma effects on substrates were investigated using contact angle goniometry and X-ray photoelectron spectroscopy (XPS). Plasma impact on coating uniformity was assessed through visualization directly and microscopically. Plasma effects on coating adhesion and bonding were studied with mechanical lap-shear testing and XPS, respectively. Substrate surface wettability and oxygen content increased with plasma exposure, and these modifications were associated with improved coating uniformity, adhesion, and interfacial covalent bonding. Findings demonstrate utility of, and elucidate mechanisms behind, plasma-based surface activation for improving coating uniformity, adherence, and performance on inert polymeric substrates.

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 979 ◽  
Author(s):  
Chunfang Zhu ◽  
Haitao Yang ◽  
Hongbo Liang ◽  
Zhengyue Wang ◽  
Jun Dong ◽  
...  

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.


2011 ◽  
Vol 687 ◽  
pp. 562-566
Author(s):  
Yan Zhang ◽  
Zhan Ping Zhang ◽  
Yu Hong Qi ◽  
Xin Rui Gao

Fluoro-polymer is of great importance as coating materials because of their excellent resistance to high temperature, chemicals and organic solvents. In the interest of researching low surface energy coating, a kind of copolymer was prepared by solution polymerization method, using methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate and perfluoroalkyl ethyl acrylate whose length of fluorinated carbon chain was from 6 to12. Solid content, monomer conversion rate and viscosity of the copolymer were measured. Parallel experiments were separately carried out with different contents of initiator and fluorinated monomer. The results showed that the water contact angle of the film becomes bigger with the increase of the content of fluorinated monomer, with the biggest value in 108° when the content of fluorinated monomer content is 30 wt%, but only changing little after content of fluorinated monomer reaches up 15 wt%. The results indicated that the copolymer can offer the best property combination when the contents of fluorinated monomer and initiator were 15 wt% and 1.8 wt%.


2016 ◽  
Vol 23 (05) ◽  
pp. 1650033 ◽  
Author(s):  
SABBIR AHMED ◽  
DEBABRATA CHAKRABARTY ◽  
SUBROTO MUKHERJEE ◽  
SHANTANU BHOWMIK

In this investigation, an attempt has been made to improve the interfacial adhesion characteristics of titanium (Ti) surface at elevated temperature and in aqueous salt solution. In order to ensure the presence of titanium oxide coating on the surface of titanium, anodization on titanium was carried out by sodium hydroxide. This oxide coating etches the surfaces of titanium. These etching surfaces of titanium increase the surface energy and surface roughness of the titanium. Physicochemical characteristics of surface modified titanium were carried out by X-ray photoelectron spectroscopy (XPS) study and the results reveal that there is a significant increase in oxygen functionalities due to anodization. The oxide etching on the surface of anodized titanium is further confirmed by scanning electron microscopy (SEM) study. The contact angle and surface energy are measured by the use of two liquids namely water and glycerol. It is observed that the formation of oxide not only improves the surface energy of titanium but also protects the surface of titanium when exposed to aggressive environments. The lap-shear tensile strengths of two anodized titanium surfaces were fabricated by adhesive. There has been significant improvement in the adhesive bond strength, and subsequently in the durability of adhesive bonded joint, of titanium when exposed to aggressive environments.


2021 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Jian Wang ◽  
Hong Chen ◽  
Xinyuan Li

A method is proposed to directly obtain superhydrophobic properties by depositing a coating made of candle soot upon the copper foil surface. The process to prepare a surface of superhydrophobicity is simple and rapid, which was performed just by placing the copper foil over the flame of a burned candle for no more than 10 minutes. The surface contact and slide angles of water were 159° ± 1.8° and 2°, respectively. Furthermore, the wettability on the copper surface of superhydrophobicity was also investigated. We found that the copper superhydrophobic surface prepared by the method had excellent superhydrophobicity for water; acid, alkali and salt solutions; and other liquids. In contrast to the traditional approach to prepare superhydrophobic surfaces, the method proposed in this study not only did not damage the mechanical properties of the substrate surface but also did not require low surface energy materials to be modified. This study provides a new approach for the protection of copper and other metallic materials.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Fernando P. S. Guastaldi ◽  
Daniel Yoo ◽  
Charles Marin ◽  
Ryo Jimbo ◽  
Nick Tovar ◽  
...  

The surface energy of the implant surface has an impact on osseointegration. In this study, 2 surfaces: nonwashed resorbable blasting media (NWRBM; control) and Ar-based nonthermal plasma 30 days (Plasma 30 days; experimental), were investigated with a focus on the surface energy. The surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and the chemistry by X-ray photoelectron spectroscopy (XPS). Five adult beagle dogs received 8 implants (n=2per surface, per tibia). After 2 weeks, the animals were euthanized, and half of the implants (n=20) were removal torqued and the other half were histologically processed (n=20). The bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were evaluated on the histologic sections. The XPS analysis showed peaks of C, Ca, O, and P for the control and experimental surfaces. While no significant difference was observed for BIC parameter (P>0.75), a higher level for torque (P<0.02) and BAFO parameter (P<0.01) was observed for the experimental group. The surface elemental chemistry was modified by the plasma and lasted for 30 days after treatment resulting in improved biomechanical fixation and bone formation at 2 weeks compared to the control group.


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 ◽  
...  

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