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Chemically adsorbed monolayers were applied to magnetic particle surfaces for preparing functional fluids. Fluorocarbon silanes were used to form the monolayers, as the methoxysilyl groups of fluorocarbon silanes can form a strong chemical bond with the surface of a magnetic particle without degrading its properties. Fluorocarbon oils were used as the carrier liquid because of their high affinity with the fluorocarbon group of the monolayers, enabling the particles to disperse easily in it. Also, fluorocarbon oils can sustain high temperature and low pressure. The functional fluids prepared using these materials showed magnetorheological characteristics and can be used under high-vacuum and/or high-temperature conditions like those encountered in space. 相似文献
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氟碳涂料是指使用了含氟树脂为基料的新型涂料,其树脂结构中的F—C键是键长最短、键能最大的化学键。氟碳涂料表面张力很低,因此具有非常出色的耐污染和自洁功能。通过对WH-1038氟碳涂料进行的工艺模拟性能试验,得出了涂料的喷涂工艺流程,并指出了使用中存在的问题。 相似文献
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The surfaces of aliphatic polyurethane films, which were synthesized by 1,6 hexamethylene diisocyanate, poly(tetramethylene glycol) and 1,4 butanediol, were modified by grafting different chain length of fluorocarbon oligomers. The fluorocarbon oligomers on polyurethane surfaces were terminated with trifluorocarbon or carboxylic acid functionality. The alkyl groups were also grafted onto polyurethane surfaces for comparison. The surface characterization and platelet-contacting property were studied using electron spectroscopy for chemical analysis (ESCA), static contact angle analysis and in vitro platelet adhesion experiments. The effects of fluorocarbon oligomers and their terminal functionalities are discussed. The ESCA results demonstrate the fluorocarbon enrichment at the outmost layer in fluorocarbon oligomer grafted polyurethanes. The fluorocarbon content at the surface increases with increasing the chain length of fluorocarbon oligomers. The fluorocarbon oligomer grafted polyurethanes exhibit highly hydrophobic surfaces, while alkyl groups grafted polyurethanes show relatively hydrophobic surfaces compared with the untreated polyurethane. The in vitro platelet adhesion experiments indicated that the fluorocarbon oligomer and carboxylic acid functionality significantly reduced the number and the degree of activation of the adherent platelets. 相似文献
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N. X TAN K. H. H LIM A. J BOURDILLON 《Journal of Materials Science: Materials in Electronics》1997,8(2):73-77
The bleeding of epoxy resin around surfaces, undergoing bonding in electronic packaging assembly, has for long caused sporadic
yield-loss. This loss is more severe in advanced and dense packages. Previously it has been supposed that the loss results
from surface contaminants which are reduced by vacuum bakeout. In fact, that procedure generates coatings of hydrocarbons
as we show by surface analysis. The coatings very strongly affect the wettabilities and measured surface energies of substrates.
In particular, the comparatively low surface energy of hydrocarbon films on gold surfaces shows how the surfaces can be engineered,
with coatings of “appropriate cleanliness”, to systematically inhibit epoxy bleeding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Hongpeng Zheng Li Liu Fandi Meng Yu Cui Zhong Li Emeka E.Oguzie Fuhui Wang 《材料科学技术学报》2021,84(25):86-96
Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceed-ingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applications in marine environments are still hindering commercial-scale deployment.This study is focused on development of easy-to-apply superhydrophobic coatings,with multifunctional capa-bilities,in order to extend the integrity and durability of the coatings in harsh marine environments.Here,a set of facile methods involving selective chemical etching using concentrated NaOH,as well as fluori-nation with perfluoropolyether methyl ester were adopted to fabricate a superhydrophobic surface on basalt scales,having the required rough hierarchical micro-nanotextured and low surface energy.The superhydrophobic basalt scales were subsequently aligned atop a fluorocarbon resin,pre-deposited on a metal substrate,to yield a multifunctional superhydrophobic coating(3 μL water droplet;contact angle=165.1°,rolling angle=0.7°),easily amenable to large surface area application and having excellent wear resistance,UV-aging resistance,salt spray resistance,corrosion resistance and antibacterial capabilities. 相似文献
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This paper deals with a new surface modification technique of polymers, the so-called ion-assisted reaction (IAR) to improve the surface properties of polymers and provides outstanding experimental results regarding wettability and adhesion of various polymers. In the IAR, polymer surfaces were subjected to low energy ion irradiation at different dosage in reactive gas environment. Dramatic improvements in wettability and surface energy are observed for the IAR-treated polymer surfaces and can be explained by the addition of functional groups, responsible for the increase of polar component in surface energy. The formation of functional groups results from the interaction among ion, reactive gas and polymer chain involved in IAR treatment, depending on the reactive ion species, the flow rate of the reactive gas and the irradiating ion fluence. The improvement in adhesion between the IAR-treated polymers and coating materials was explained in terms of the increased surface energy as well as surface roughness in the polymers modified by the IAR and possible adhesion enhancement mechanism is to be discussed. 相似文献
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Pereira C Alves C Monteiro A Magén C Pereira AM Ibarra A Ibarra MR Tavares PB Araújo JP Blanco G Pintado JM Carvalho AP Pires J Pereira MF Freire C 《ACS applied materials & interfaces》2011,3(7):2289-2299
This work reports the synthesis and characterization of mesoporous silica nanoparticles (MSNs) functionalized with tridecafluorooctyltriethoxysilane (F13) and their in situ incorporation onto cotton textiles. The hybrid MSNs and the functional textiles were prepared by a one-pot co-condensation methodology between tetraethylorthosilicate (TEOS) and F13, with hexadecyltrimethylammonium chloride (CTAC) as the template and triethanolamine as the base. The influence of the F13 to TEOS molar ratio (1:10, 1:5 and 1:3) on the nanoparticle morphology, porosity, degree of functionalization, and hydro/oleophobic properties is discussed. The hybrid nanosilicas presented high colloidal stability and were spherical and monodispersed with average particle size of ~45 nm. They also showed high surface areas, large pore volumes, and a wormhole-type mesoporous structure. The increase in the organosilane proportion during the co-condensation process led to a more radially branched wormhole-like mesoporosity, a decrease in the surface area, pore volume, and amount of surface silanol groups, and an enrichment of the surface with fluorocarbon moieties. These changes imparted hydrophobic and oleophobic properties to the materials, especially to that containing the highest F13 loading. Cotton textiles were coated with the F13-MSNs through an efficient and less time-consuming route. The combination between surface roughness and mesoporosity imparted by the MSNs, and the low surface energy provided by the organosilane resulted in superhydrophobic functional textiles. Moreover, the textile with the highest loading of fluorocarbon groups was superamphiphobic. 相似文献
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Plasmapolymer coatings for tailor‐made functional surfaces The tailoring of surface properties via polymer coatings is currently a strongly pursued topic in various fields ranging from microsystem technology to bioanalytics. A precise tuning of surface properties, however, is only possible if chemically well‐defined processes are used that usually require reactive surface moieties to which molecules can be coupled. In this contribution we summarize studies that aimed at the modification of inert surfaces. For this purpose reactive groups at the surfaces are generated by plasma polymerisation of allyl amine which results in layers that contain amino groups. Initiator molecules for free radical polymerization processes are then coupled to these amino groups resulting in surfaces from which polymers can then be grown via surface‐initiated polymerization. Using these processes, polymer monolayers with very different properties can be generated by simply using different monomers. 相似文献
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Chemical nature of superhydrophobic aluminum alloy surfaces produced via a one-step process using fluoroalkyl-silane in a base medium 总被引:1,自引:0,他引:1
Saleema N Sarkar DK Gallant D Paynter RW Chen XG 《ACS applied materials & interfaces》2011,3(12):4775-4781
Various surface characterization techniques were used to study the modified surface chemistry of superhydrophobic aluminum alloy surfaces prepared by immersing the substrates in an aqueous solution containing sodium hydroxide and fluoroalkyl-silane (FAS-17) molecules. The creation of a rough micronanostructure on the treated surfaces was revealed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) and infrared reflection absorption spectroscopy (IRRAS) confirmed the presence of low surface energy functional groups of fluorinated carbon on the superhydrophobic surfaces. IRRAS also revealed the presence of a large number of OH groups on the hydrophilic surfaces. A possible bonding mechanism of the FAS-17 molecules with the aluminum alloy surfaces has been suggested based on the IRRAS and XPS studies. The resulting surfaces demonstrated water contact angles as high as ~166° and contact angle hystereses as low as ~4.5°. A correlation between the contact angle, rms roughnesses, and the chemical nature of the surface has been elucidated. 相似文献
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Plasma deposition was applied to deposit smooth and nanostructured fluorocarbon coatings on polyethylene terephthalate substrates, with the aim to obtain surfaces with identical chemical composition but different roughness to improve the endothelialization process on PET surfaces. We found that increased roughness was associated with enhanced endothelial cell response, as shown by the ability of cells to grow and adhere to nanostructures. We also observed specific interaction of filopodia protruding from the cell membrane with individual nanostructures, leading to increased cell attachment, spreading and cell viability. Among the modified surfaces, one termed PET-tfl90 emerged as the one capable of best sustaining the formation of a confluent monolayer of endothelial cells. In conclusion, PET modified by nanostructured fluorocarbon film represents an improved graft material, over conventional PET, for endothelial cell adhesion and growth. 相似文献
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低表面能防污涂料的最新研究进展 总被引:5,自引:1,他引:5
低表面能防污涂料(有机硅系列和氟化物系列)因具有独特的性能而在许多领域得到广泛应用.介绍了低表面能防污涂料防污的作用机理、特点,综述了低表面能防污涂料的应用和最新进展,并阐述了低表面能防污涂料有待解决的问题和今后的发展方向. 相似文献
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Schweikl H Müller R Englert C Hiller KA Kujat R Nerlich M Schmalz G 《Journal of materials science. Materials in medicine》2007,18(10):1895-1905
Physical and chemical properties of the surfaces of implants are of considerable interest for dental and orthopedic applications.
We used self-assembled monolayers (SAMs) terminated by various functional chemical groups to study the effect of surface chemistry
on cell behavior. Cell morphology and proliferation on silicon wafers of various roughnesses and topographies created by chemical
etching in caustic solution and by corundum sandblasting were analyzed as well. Water contact angle data indicated that oxidized
wafer surfaces displayed high hydrophilicity, modification with poly(ethylene glycol) (PEG) created a hydrophilic surface,
and an amino group (NH2) led to a moderately wettable surface. A hydrophobic surface was formed by hydrocarbon chains terminated by CH3, but this hydrophobicity was even further increased by a fluorocarbon (CF3) group. Cell proliferation on these surfaces was different depending primarily on the chemistry of the terminating groups
rather than on wettability. Cell proliferation on CH3 was as high as on NH2 and hydrophilic oxidized surfaces, but significantly lower on CF3. Precoating of silicon wafers with cell culture serum had no significant influence on cell proliferation. Scanning electron
microscopy indicated a very weak initial cell-surface contact on CF3. The cell number of osteoblasts was significantly lower on sandblasted surfaces compared with other rough surfaces but no
differences were detected with 3T3 mouse fibroblasts. The different surface roughnesses and topographies were recognized by
MG-63 osteoblasts. The cells spread well on smooth surfaces but appeared smaller on a rough and unique pyramid-shaped surface
and on a rough sandblasted surface. 相似文献
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Wettability of a solid surface by a liquid plays an important role in several phenomena and applications, for example in adhesion, printing, and self‐cleaning. In particular, wetting of rough surfaces has attracted great scientific interest in recent decades. Superhydrophobic surfaces, which possess extraordinary water repelling properties due to their low surface energy and specific nanometer‐ and micrometer‐scale roughness, are of particular interest due to the great variety of potential applications ranging from self‐cleaning surfaces to microfluidic devices. In recent years, the potential of superhydrophobic cellulose‐based materials in the function of smart devices and functional clothing has been recognized, and in the past few years cellulose‐based materials have established themselves among the most frequently used substrates for superhydrophobic coatings. In this Review, over 40 different approaches to fabricate superhydrophobic coatings on cellulose‐based materials are discussed in detail. In addition to the anti‐wetting properties of the coatings, particular attention is paid to coating durability and other incorporated functionalities such as gas permeability, transparency, UV‐shielding, photoactivity, and self‐healing properties. Potential applications for the superhydrophobic cellulose‐based materials range from water‐ and stain‐repellent, self‐cleaning and breathable clothing to cheap and disposable lab‐on‐a‐chip devices made from renewable sources with reduced material consumption. 相似文献
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Cornelia Bellmann Victoria Albrecht Jan Roth John Cremers Dieter Pleul Karina Grundke 《真空研究与实践》2010,22(6):26-30
Modification of non‐polar polymer surfaces In numerous technological relevant processes the adhesion in compound systems is of central importance. It concerns for example surface coatings and the manufacturing of composites. Particular problems result at the compounding of polyolefins, silicones and fluoropolymers due to their very low surface energy. The modification of such polymer surfaces with the aim of functionalisation and with it of increasing the surface energy results in an improvement of adhesion properties of the materials. A well‐established procedure, particularly in the automotive industry, is the flame treatment of the surfaces. However, a defined chemical modification of the surface depends on many parameters and thus is very difficult to standardize. A defined change of the surface can be better achieved through a targeted plasma treatment, in which in our case the surface is stabilized by a subsequent wet chemical process step. 相似文献
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Plasma in a bag — Internal coating of bags using atmospheric pressure plasmas for cell culturing. “Plasma in a bag” stands for a new low‐cost technique for coating the inside of closed plastic bags by means of atmospheric pressure plasma. The technique allows the deposition of homogeneous, long‐term stable functional layers on the inner surfaces of cell culture bags. The area density of functional amino groups was determined by chemical derivatization in combination with ATR‐FTIR spectroscopy. A prototype of an equipment was built for the automated and reproducible deposition of coatings under standard laboratory conditions maintaining the sterility of the bag. High yields of adherent grown human mesenchymal stem cells can be achieved even after long periods of storage of the bag before use. With suitable variation of the film‐forming agent different functionalities can be obtained on the surface. Future goals are the deposition of migration barriers as well as the coating of bottles with hydrophobic surfaces. 相似文献
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Philipp Rahe Markus Kittelmann Julia L. Neff Markus Nimmrich Michael Reichling Philipp Maass Angelika Kühnle 《Advanced materials (Deerfield Beach, Fla.)》2013,25(29):3948-3956
Molecular self‐assembly constitutes a versatile strategy for creating functional structures on surfaces. Tuning the subtle balance between intermolecular and molecule‐surface interactions allows structure formation to be tailored at the single‐molecule level. While metal surfaces usually exhibit interaction strengths in an energy range that favors molecular self‐assembly, dielectric surfaces having low surface energies often lack sufficient interactions with adsorbed molecules. As a consequence, application‐relevant, bulk insulating materials pose significant challenges when considering them as supporting substrates for molecular self‐assembly. Here, the current status of molecular self‐assembly on surfaces of wide‐bandgap dielectric crystals, investigated under ultrahigh vacuum conditions at room temperature, is reviewed. To address the major issues currently limiting the applicability of molecular self‐assembly principles in the case of dielectric surfaces, a systematic discussion of general strategies is provided for anchoring organic molecules to bulk insulating materials. 相似文献