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1.
Small ; 20(30): e2312112, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38409650

RESUMEN

Harvesting freshwater from fog is one of the possible solutions to the global water scarcity crisis. Surfaces with both hydrophobic and hydrophilic regions are extensively employed for this purpose. Nevertheless, the longevity of these surfaces is still constrained by their delicate surface structures. The hydrophilic zones may become damaged or contaminated after repeated use, thereby compromising their effectiveness in fog collection. The preparation of generally applicable durable superhydrophobic coatings with self-generated Wenzel sites is reported here for long-term efficient and stable fog collection. The coatings are prepared by depositing the poly(tannic acid) coating as the primer layer on various substrates, self-assembly of trichlorovinylsilane into staggered silicone nanofilaments, and then thiol-ene click reaction with 1H,1H,2H,2H-perfluorodecanethiol. The coatings demonstrate remarkable static superhydrophobicity, robust impalement resistance, and stable self-generated Wenzel sites for water droplets. Therefore, the fog collection rate (FCR) of the coatings reaches 2.13 g cm-2 h-1 during 192 h continuous fog collection, which is triple that of bare substrate and outperforms most previous studies. Moreover, the systematic experiments and models have revealed that the key factors for achieving high FCR on superhydrophobic coatings are forming condensed droplets ≈1 mm in critical radius and a Wenzel site proportion of 0.3-0.4.

2.
Langmuir ; 40(14): 7760-7768, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38546182

RESUMEN

Superhydrophobic coatings hold immense promise for various applications. However, their practical use is currently hindered by issues such as poor stability, high costs, and complex preparation processes. Here, we present the preparation of cost-effective and stable superhydrophobic coatings through fluorination of natural attapulgite (F-ATP) nanorods and subsequent solvent-induced phase separation of a silicone-modified polyester adhesive (SMPA) with the F-ATP nanorods dispersed in it. Phase separation of the F-ATP/SMPA system forms a uniform suspension of microaggregates, which can be easily utilized for preparing superhydrophobic coatings via spray coating. The coatings have a low-surface-energy hierarchical micro/nanostructure due to phase separation of SMPA and adhesion of F-ATP to it. Moreover, the effects of the solvent composition (i.e., phase separation degree of SMPA) and the SMPA/F-ATP mass ratio on the morphology, superhydrophobicity, and stability of the coatings were investigated. After systematic optimization, the coatings exhibit excellent static and dynamic superhydrophobicity as well as high mechanical, chemical, thermal, and UV aging stability. Finally, the coatings were applied to the 5G radome surface and showed good rain attenuation prevention performance. Thus, we are confident that the superhydrophobic coatings have great application potential due to their advantages of outstanding performance, straightforward preparation procedures, cost-effectiveness, etc.

3.
Langmuir ; 40(1): 1109-1116, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38148548

RESUMEN

Superamphiphobic coatings have good application prospects in many fields but are limited by their low impalement resistance, weak mechanical stability, and easy adhesion of tiny droplets. Here, impalement-resistant, mechanically stable, and antistatic superamphiphobic coatings were fabricated by spraying a mixture of conductive carbon black (CB), silicone-modified polyester adhesive/fluorinated SiO2 microspheres onto Al alloy. The microspheres were obtained by adhesive phase separation and the binding of fluorinated SiO2 to them. The morphology, superamphiphobicity, impalement resistance, and mechanical stability of the coatings could be regulated by using solvents with different boiling points. As a result, the coatings simultaneously exhibited outstanding mechanical stability, impalement resistance, and superamphiphobicity. The addition of conductive CB endowed the coatings with good antistatic and tiny droplet repellent properties. In addition, the coatings exhibited good anti-icing properties due to the steady air layer at the solid-liquid interface and the very small contact area between them. We suppose that the coatings are very promising for practical application in various fields, including anti-icing, due to their outstanding comprehensive properties and simple preparation process.

4.
Langmuir ; 37(45): 13527-13536, 2021 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-34724379

RESUMEN

Self-healing superhydrophobic coatings have a wide potential for practical applications by prolonging their lifespan, but still suffer from some shortcomings, for example, difficulty in repairing microstructure damage, limited self-healing cycles, and more importantly the inability to self-heal while in service. Herein, we present the fabrication of superhydrophobic coatings having photothermal self-healing chemical composition and microstructure for the high performance anticorrosion of Mg alloy. The coatings contain a shape-memory polymer (SMP) primer and an upper superhydrophobic coating composed of fluorinated polysiloxane-modified multiwalled carbon nanotubes (PF-POS@MWCNTs). The coatings have good superhydrophobicity, photothermal effect, and anticorrosion performance. The coatings show excellent self-healing performance in response to chemical and microstructure damage, such as rapid self-healing under 1 sun irradiation in 10 min, complete self-healing after serious damage (e.g., 10 damage and self-healing cycles and complex microstructure damage), and even self-healing under natural sunlight in 4 h. Moreover, the self-healed coatings show good corrosion protection for magnesium alloy in the neutral salt spray test. These are because of the combination of the SMP primer with good shape-memory effect and the PF-POS@MWCNTs coating with good superhydrophobicity, photothermal effect, and embedded PF-POS. The coatings are self-healable under natural sunlight while in service and thus may find applications in diverse fields.

5.
Anal Biochem ; 579: 9-17, 2019 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-31078490

RESUMEN

A polydopamine magnetic composite (PDA@Fe3O4) was prepared for the extraction of human genomic DNA and characterized by transmission electron microscopy, X-ray diffraction, FT-IR spectrometer, zeta potential and vibrating sample magnetometry. PDA@Fe3O4 based on magnetic solid phase extraction (MSPE) method have highly efficient capture of genomic deoxyribonucleic acid (DNA)and gene fragments ranging from about 100 bp to 200 bp. Compared with commercial beads (Shenggong, China) and spin column nucleic acid extraction kit (Tiangen, China), the PDA coated magnetic nanoparticles display superior genomic DNA extraction capacity (116 mg/g) and yield (90.2%). The isolation protocol used the solutions (composed of PEG and NaCl) with a specific pH for the binding and release of DNA. The procedure can be attributed to the charge switch of amino and hydroxyl groups on surface of the magnetic particle. The extracted DNA with high quality (A260/A280 = 1.82 ±â€¯0.04) can be directly used as template for polymerase chain reaction (PCR) followed by agarose gel electrophoresis. The results showed the new composite to be an ideal adsorbent for separation of DNA which had the advantage of its low cost, high extraction capacity and yield.


Asunto(s)
ADN/sangre , ADN/aislamiento & purificación , Indoles/química , Nanopartículas de Magnetita/química , Polímeros/química , Extracción en Fase Sólida/métodos , Adsorción , Humanos
6.
Langmuir ; 33(2): 510-518, 2017 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-28025880

RESUMEN

Although encouraging progress in the field of superamphiphobic coatings has been obtained, the superamphiphobic coatings with high durability, transparency, and repellency to hot liquids are very rare. Here, durable, transparent, and hot liquid-repelling superamphiphobic coatings were successfully prepared using polysiloxane-modified multiwalled carbon nanotubes (MWCNTs@POS) as the templates. The hydrolytic condensation of n-hexadecyltrimethoxysilane (HDTMS) and tetraethoxysilane on the surface of MWCNTs formed MWCNTs@POS, which are highly dispersible in toluene. The superamphiphobic coatings were prepared by spray-coating the homogeneous suspension of MWCNTs@POS in toluene onto glass slides, calcination in air to form the silica nanotubes (SNTs), and then modification with 1H,1H,2H,2H-perfluorodecyltrichlorosilane in dry toluene. The changes in the surface microstructure, surface chemical composition, and wettability were characterized by various techniques such as scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was found that the microstructures of the SNTs have great influences on superamphiphobicity and transparency of the coatings and can be regulated by the concentration of HDTMS and the diameter of MWCNTs. The SNTs with tunable wall thickness and diameter could be obtained using the method. The superamphiphobic coatings showed high contact angles and low sliding angles for various cool and hot liquids of different surface tensions. The superamphiphobic coatings also exhibited high transparency and comprehensive durability.

7.
Langmuir ; 30(47): 14292-9, 2014 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-25378097

RESUMEN

The newly developed Nepenthes pitcher (NP)-inspired slippery surfaces, formed by immobilizing fluoroliquids on lotus leaf (LL)-inspired superoleophobic surfaces, are of great general interest, whereas there are many interesting phenomena and fundamental scientific issues remaining to be unveiled. Here we present our findings of the effects of evaporation of the fluoroliquid, an inevitable process in most cases, -induced transition from NP-inspired to LL-inspired surfaces on the wettability, transparency, and self-cleaning property of the surfaces. The transition is controlled by regulating the evaporation temperature of the model fluoroliquid, Krytox100. The evaporation of Krytox100 has great a influence on the wettability, transparency, and self-cleaning property. An intermediate "sticky" state is observed in the transition process. We believe that our findings in the transition process are helpful in understanding the similarities and differences between the NP-inspired and LL-inspired surfaces and in designing new bioinspired antiwetting surfaces and exploring their potential applications.

8.
Chem Asian J ; 19(9): e202400110, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38481082

RESUMEN

Photothermal superhydrophobic coatings hold great promise in addressing the limitations of conventional superhydrophobic anti-icing coatings. However, developing such coatings with excellent impalement resistance, mechanical robustness and weather resistance remains a significant challenge. Here, we report facile preparation of robust photothermal superhydrophobic coatings with all the above advantages. The coatings were prepared by spraying a dispersion consisting of fluorinated silica nanoparticles, a silicone-modified polyester adhesive and photothermal carbon black nanoparticles onto Al alloy plates followed by thermal curing. Thermal curing caused migration of perfluorodecyl polysiloxane from within the coatings to the surface, effectively maintaining a low surface energy despite the presence of the adhesive. Therefore, combined with the hierarchical micro-/nanostructure, dense yet rough nanostructure, adhesion of the adhesive and chemically inert components, the coatings exhibited remarkable superhydrophobicity, impalement resistance, mechanical robustness and weather resistance. Furthermore, the coatings demonstrated excellent photothermal effect even in the -10 °C, 80 % relative humidity and weak sunlight (0.2 sun) environment. Consequently, the coatings showed excellent passive anti-icing and active de-icing performance. Moreover, the coatings have good generalizability and scalability. We are confident that this study will accelerate the practical implementation of photothermal superhydrophobic coatings.

9.
Sci Adv ; 9(42): eadj1554, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-37862425

RESUMEN

Superhydrophobic (SH) surfaces have progressed rapidly in fundamental research over the past 20 years, but their practical applications lag far behind. In this perspective, we first present the findings of a survey on the current state of SH surfaces including fundamental research, patenting, and commercialization. On the basis of the survey and our experience, this perspective explores the challenges and strategies for commercialization and widespread practical applications of SH surfaces. The comprehensive performances, preparation methods, and application scenarios of SH surfaces are the major constraints. These challenges should be addressed simultaneously, and the actionable strategies are provided. We then highlight the standard test methods of the comprehensive performances including mechanical stability, impalement resistance, and weather resistance. Last, the prospects of SH surfaces in the future are discussed. We anticipate that SH surfaces may be widely commercialized and used in practical applications around the year 2035 through combination of the suggested strategies and input from both academia and industry.

10.
ACS Appl Mater Interfaces ; 14(43): 49224-49232, 2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36260419

RESUMEN

Lithium-sulfur (Li-S) batteries are very promising high-energy-density electrochemical energy storage devices, but suffer from serious Li polysulfide (LiPS) shuttle and uncontrollable Li dendrite growth. Here, we show in situ polyolefin separator modification with an N-rich conjugated microporous polymer (NCMP) for advanced Li-S battery. In situ polymerization generates an ultrathin NCMP coating on the whole external surface and the internal surface of the separator, which is substantially different from the conventional approaches with thick coatings only on the external surface. The NCMP coating with abundant N-containing groups (-NH2 and -N═), uniform nanopores (12.294 Å), and π-conjugated structure can simultaneously inhibit LiPS shuttle and regulate uniform nucleation and growth of Li dendrites. Consequently, the NCMP-based separator endows the Li-S battery with significantly enhanced cycling stability at high S loading (5.4 mg cm-2), lean electrolyte (E/S = 6.3 µL mg-1), and limited Li excess (50 µm).

11.
J Colloid Interface Sci ; 594: 836-847, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33794405

RESUMEN

Magnesium (Mg) alloy has wide potential applications due to its unique properties, but is apt to corrosion. Recently, superhydrophobic coatings are receiving great interest for corrosion protection of metals but suffer from short lifespan. Here, we report a strategy for long-term corrosion protection of Mg alloy by designing two-layer self-healing superamphiphobic coatings based on shape memory polymers (SMP) and attapulgite. The superamphiphobic coatings are composed of a bottom SMP coating containing a corrosion inhibitor (1, 2, 3-benzotriazole, BTA) and ceresine wax microparticles and a top superamphiphobic attapulgite coating. The two-layer self-healing coatings have excellent superamphiphobicity and initial anti-corrosion performance. The Mg alloy with the coatings can withstand immersion in 3.5 wt% NaCl solution for 80 days and neutral salt spray with 5 wt% NaCl for 54 days. Furthermore, the coatings show excellent self-healing capability towards various physical damages, such as 10 scratching/self-healing cycles at the same position, hexagonal star scratching and grid scratching. Moreover, the physically damaged coatings exhibit self-healing behavior of the microstructure and superhydrophobicity, driven by the shape memory effect of the bottom SMP layer. Thus, the self-healed coatings can still withstand 60 days of 3.5 wt% NaCl solution immersion and 30 days of 5 wt% NaCl salt spray. This study paves the way for applying super anti-wetting coatings for long-term corrosion protection of metals.

12.
J Colloid Interface Sci ; 591: 429-439, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33631530

RESUMEN

Anti-fouling coatings are of great interest because of their unique wettability and self-cleaning property, but their widespread applications are seriously hindered by low stability, heavy usage of fluorinated compounds and low transparency, etc. Here, we report a new kind of smooth anti-fouling coatings based on methyltrimethoxysilane. The coatings were fabricated by preparing a stock solution via hydrolytic condensation of methyltrimethoxysilane in isopropanol, followed by wiping the glass slide with the non-woven fabric that sucked the stock solution. The transparent anti-fouling coatings have excellent anti-fouling properties against various fluids such as water, n-hexadecane, diiodomethane, daily encountered liquids (e.g., milk, coffee, red wine, soy sauce and cooking oil), mark seals, artificial fingerprint liquids and paints (both water-based and oil-based), etc. The fluids can easily roll off from the 4-30° titled coatings. Furthermore, the coatings have good mechanical (200 cycles of friction, scratching and bending), chemical (saline, acidic and basic solutions) and thermal stability (boiling and 300 °C heating) regarding the easy sliding behavior of the probing liquids. In addition, the anti-fouling coatings are applicable onto various substrates via the same procedure. The smooth anti-fouling coatings have huge potential applications, owing to the excellent anti-fouling properties, high stability as well as the non-fluorinated and simple preparation method.

13.
J Colloid Interface Sci ; 566: 69-78, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-31991366

RESUMEN

Scald is a kind of common injury for human beings caused by contacting with hot liquids and/or vapor. Herein, we report the preparation of an advanced fabric for efficient scald-preventing by dip-coating a common polyester fabric in a hexadecyl polysiloxane (HD-POS) aqueous suspension, which was synthesized via a waterborne and nonfluorinated approach. Thanks to the hierarchical micro-/nanostructure of the fabric, stable bonding of the compact HD-POS layer on the polyester microfibers, and inherent high stability and elasticity of HD-POS, the fabric features excellent hot water repellency even for dynamic boiling water with a high water impalement resistance of up to 5 grades according to the water repellency grade test. In addition, the fabric shows extraordinary mechanical stability, e.g., its superhydrophobicity remained nearly unchanged after 200 cycles washing, 10,000 cycles Martindale abraison or 1000 cycles 100% streching and releasing. It also exhibits superior environmental robustness (117 d outdoor test) and chemical robustness (7 d immersion in 1 M HCl or NaOH solution, 60 min ultrosonication in both water and anchol immersion) in various harsh conditions. By applying as an advanced fabric for efficient scald-preventing, it can avoid direct contact of hot water and vapor with rat skin by preventing penetration of hot water and most of vapor. It could also significantly reduce heat conduction and radiation to rat skin by reducing contact time of hot water with the fabric (decreased 10 s more quickly than the pristine fabric to 60 °C when encountering 100 mL of 92 °C water). As a result, the fabric in contact with the skin keeps dry and the fabric temperature is much lower than that of the pristine fabric once encountering hot water, thus showing great potentials as an advanced fabric for efficient scald-preventing applications.


Asunto(s)
Poliésteres/química , Siloxanos/química , Agua/química , Tamaño de la Partícula , Poliésteres/síntesis química , Propiedades de Superficie
14.
J Colloid Interface Sci ; 578: 262-272, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32531556

RESUMEN

Superamphiphobic coatings have attracted great attention in academia and industry. However, the fabrication of durable superamphiphobic coatings with high repellency towards liquids with low surface tension and high viscosity is still very challenging. Here, we report a simple method for the fabrication of durable superamphiphobic coatings with high static and dynamic repellency to such liquids. First, a homogeneous suspension was fabricated by hydrolytic condensation of silanes in the presence of the chain-like aggregates of SiO2 nanoparticles. Subsequently, the superamphiphobic coatings were fabricated by spray-coating the polyurethane adhesive onto the substrates followed by spray-coating the as-prepared suspension onto the polyurethane adhesive layer. The coatings show high repellency to liquids with low surface tension and high viscosity, e.g., high apparent contact angles, low sliding angles, high impact resistance, low horizontal deformation and fast rolling velocity. Furthermore, the coatings show excellent mechanical durability against intensive sandpaper abrasion (60 m of abrasion under 10.5 kPa), water impact (60 min under 100 kPa) and tape peeling (200 cycles). The coatings also exhibit good aging stability. Based on these merits, the superamphiphobic coatings may have great potentials in various applications, e.g., handling with natural and synthetic polymer solutions.

15.
J Colloid Interface Sci ; 575: 140-149, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32361230

RESUMEN

Magnesium alloys have many excellent properties, but the poor corrosion resistance seriously hinders their widespread applications. Here, we report a self-healing superamphiphobic coating for efficient corrosion protection of magnesium alloy by the combination of a compact self-healing epoxy resin (SHEP) coating and a porous superamphiphobic coating. The coating shows (i) excellent superamphiphobicity with high contact angle, low sliding angle and robust impact/bounce behavior, (ii) excellent anti-corrosion performance as demonstrated by the potentiodynamic polarization curves and electrochemical impedance spectroscopy, and (iii) excellent self-healing performance as proved by the scanning electron microscopy and electrochemical impedance spectroscopy. This is owing to synergistic effect of the bi-layer structure. Furthermore, the healed coating retained excellent anti-corrosion performance according to the immersion test and neutral salt spray test. This is because the SHEP layer can effectively drive repair of microstructure of the superamphiphobic layer, and then recover of superamphiphobicity. Therefore, the contact area and contact time of corrosive solutions with the pristine and healed coatings are limited, which efficiently prevents diffusion of corrosive substances such as water, chloride ions and oxygen. The self-healing superamphiphobic coating may find applications in protection of various metal alloys.

16.
iScience ; 16: 420-432, 2019 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-31229891

RESUMEN

Conventional polyolefin separators suffer from poor wettability to liquid electrolytes (LEs). Although some modified separators exhibit improved wettability, they are hydrophilic, causing inevitable moisture uptake. Trace water could result in poor performance and safety hazard of Li metal batteries. Here, we report a design idea of superLEphilic/superhydrophobic and thermostable separators by modifying the Celgard separator using silicone nanofilaments. The separator features low moisture uptake (∼0%), fast LE diffusion (454 ms), and high LE uptake (287.8%), LE retention rate, and Li+ conductivity. Consequently, the Li/LiFePO4 cells show high cycling stability (96.05% after 350 cycles), good rate performance (125 mA h g-1 at 5.0 C), low resistance, and stable open circuit voltage at 160°C. Moreover, the separator could improve performance of the other Li metal batteries with high-voltage cathodes and the LiFePO4/graphite pouch cells. This work provides an avenue for designing advanced separators by using bioinspired superwetting surfaces.

17.
J Colloid Interface Sci ; 554: 250-259, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31301525

RESUMEN

Superamphiphobic surfaces have attracted extensive attention from both academic and commercial communities because of their unique wettability. However, big challenge still remains as superamphiphobic surfaces frequently suffer the drawbacks of either easy adhesion of liquids with low surface tension (<27.5 mN m-1) or low transparency, which in turn seriously hinders their applications. Here, we report the exploitation of highly transparent superamphiphobic surfaces, which was prepared by chemical vapor deposition (CVD) of 1H,1H,2H,2H-perfluorodecyltrichlorosilane onto silica nanotubes, via elaborate microstructure regulation. The silica nanotubes are synthesized by coating multiwalled carbon nanotubes (MWCNTs) with a layer of polysiloxane followed by calcination in air. The effects of various parameters, including the concentration of MWCNTs, the solvents for re-dispersing the polysiloxane-modified MWCNTs and its spray-coating density, on superamphiphobicity and transparency were systematically studied. The results show that the superamphiphobicity and transparency are highly dependent on the solvents for re-dispersing polysiloxane-modified MWCNTs because the microstructure of the polysiloxane layer, i.e. the precursor of silica nanotubes, relies on the re-dispersing solvents. The superamphiphobic coatings feature extremely low sliding angles for various liquids with surface tension as low as 21.6 mN m-1 and very high optical transparency, superior to most of the reported superamphiphobic surfaces, which make them promising candidates as functional surfaces or coatings for a broad variety of applications, e.g., in situ observation using microscopes, self-cleaning windows, and so on.

18.
J Colloid Interface Sci ; 542: 8-14, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30721836

RESUMEN

The literatures about superhydrophobic coatings (SHCs) are increasing every year, however, undesirable chemicals including organic solvents and fluorinated compounds are intensively used in the existing preparation methods, which seriously hinder their large scale production and practical applications. Herein, a simple approach for preparation of totally waterborne, fluorine-free and durable SHCs is reported. First, a waterborne suspension of hexadecyl polysiloxane modified SiO2 (SiO2@HD-POS) was prepared via HCl-catalyzed hydrolytic condensation of hexadecyltrimethoxysilane (HDTMS) and tetraethoxysilane with SiO2 nanoparticles. The SHCs with high water contact angles (CA = 163.9°) and low sliding angles (SA = 3.7°) were prepared simply by sequentially spray-coating a polyurethane (PU) waterborne solution and the SiO2@HD-POS waterborne suspension onto glass slides. The influences of SiO2, HDTMS, reaction time and fabrication temperature on superhydrophobicity were investigated. The SHCs can withstand 80 m of reciprocating abrasion against A4 paper at 4.5 kPa and impacting of at least 50 g of sand microparticles with 30 cm release height. Moreover, the coatings also show exceptional thermostability in boiling water. The SHCs showed promising applications in various areas including oil/water separation and preventing scald, as the method is environmental benign and the coatings are applicable onto various substrates.

19.
Sci Rep ; 9(1): 702, 2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30679771

RESUMEN

For almost all the research of super anti-wetting surfaces, pure liquids like water and n-hexadecane are used as the probes. However, liquids of diverse compositions are used in academic research, industrial production and our daily life. Obviously, the liquid repellency of super anti-wetting coatings is highly dependent on properties of the liquids. Here, we report the first superamphiphobic surface with high repellency towards liquids of extremely high viscosity and low surface tension. The surfaces were prepared by constructing a hierarchical micro-/nanostructure on the Cu micropillar arrays followed by modification with perfluorosilane. The surfaces are superamphiphobic towards the liquids with extremely high viscosity and low surface tension because of (i) the micro-/nanostructured surface composed of micropillars with proper pillar distance and CuO nano-flowers, and (ii) the abundant perfluorodecyl groups on the surface. The contact angles, sliding angles, apparent contact line at the solid-liquid interface and adhesion forces are the end products of micropillar distance, viscosity and surface tension. Smaller micropillar distance, higher viscosity and higher surface tension contribute to reducing the adhesion force. We in situ observed the process of microcapillary bridge rupture for the first time using highly viscous liquids. We also successfully reduced the adhesion forces and enhanced the average rolling velocity of liquids with extremely high viscosity and low surface tension by regulating the micropillar distance.

20.
J Colloid Interface Sci ; 540: 228-236, 2019 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-30641400

RESUMEN

Although significant attention has been paid, most of superamphiphobic surfaces suffer from high sliding angles (SA) for liquids with low surface tension and complicated preparation methods. Also, superamphiphobic coatings with high repellency to the liquids with very high viscosity and low surface tension are rare. Here, we report preparation of clay-based superamphiphobic coatings with low SAs for viscous liquids. A homogeneous suspension was prepared by hydrolytic condensation of 1H,1H,2H,2H-perfluorodecyltriethoxysilane and tetraethoxysilane in the existence of attapulgite, a kind of natural clay mineral with nanorods-like microstructure. The superamphiphobic coatings were readily prepared by spray-coating the suspension onto substrates. The effects of attapulgite on microstructure and superamphiphobicity of the coatings were studied. Also, the static and dynamic superamphiphobicity were investigated. The attapulgite concentration has great influences on superamphiphobicity and solid-liquid adhesion force of the coatings, as it determines microstructure of the coatings. The superamphiphobic surfaces feature high contact angles and low SAs for various liquids including those with extremely high viscosity and low surface tension, e.g., hydroxyl-terminated polybutadiene (HTPB) and the HTPB/Al mixture (1:1, w/w). The coating also shows low solid-liquid adhesion force, high impact resistance and fast rolling of various liquids.

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