Wettability-driven synergistic resistance of scale and oil on robust superamphiphobic coating

Disgusting deposits(e.g.,scale and crude oil)in daily life and industrial production are always serious problems,posing great threats to the safety and economic development.However,most of developed coatings can only conquer one part of these deposits such as superhydrophobic coatings possess antiscaling capacity but would adhere crude oil.To integrate scale resistance with oil repellence,we herein report a robust superamphiphobic(SAB)coating simultaneously reducing pollution of scale and oil for extended period of time(two weeks with over 98%reduction).Compared with single role of superhydrophobic and amphiphilic surfaces,the SAB coating can not only inhibit interfacial nucleation of scale but also reduce the adhesion of formed scale and polluted oil.The durability of the SAB coating is evaluated via mechanical tests(sandpaper abrasion,tape stripping and sand falling)and chemical corrosion(corrosive liquid immersing),revealed by sustainable high contact angles and low contact angle hysteresis of water and oil.The universality of this strategy can be further confirmed by adding different particles like kaolin,Al_(2)O_(3),and SiO_(2),resisting multiple types of scale(i.e.,CaSO_(4),BaSO_(4)and MgCO_(3))and oil(i.e.,glycerol,glycol,and mineral oil).Therefore,this study provides an ideal avenue for resisting scale and oil,which may be used for conquering the complexity of application environments(e.g.,oil production and transportation).

Novel Waterborne Fluorinated Polyurethane Containing Fluoroalkyl Side Chain:Synthesis,Characterization and Application on Cotton Fabric

A polyether diol poly[3-bromomethyl-3-tridecafluorooctyloxymethyloxetane]glycol(PFBOX 3) was prepared in 91% yield from ring opening polymerization of 3-bromomethyl-3-tridecafluorooctyloxymethyloxetane 2 which was derived from 3,3-dibromomethyloxetane 1 and 1H,1H,2H,2H-perfluorooctanol.The waterborne fluorinated polyurethane FPU was thus obtained by condensed polymerization of PFBOX 3 with isophoronediisocyanate(IPDI).The structure of FPU was characterized by Fourier transform infrared spectrometer(FTIR).FPU showed good thermal stability under 300℃.The surface properties of FPU were studied by applied on cotton fabric.The treated fabric surface showed excellent water repellent property as the contact angle reached 147°.On the other hand,the surface showed slightly oil repellent property as the contact angle for nujol droplet was 126°.

Synthesis of Novel Fluorinated Acrylate Co-polymers and Their Application on Cotton Fabrics

Two novel fluorinated acrylate monomers 4a and 4b containing perfluorohexyl group were designed and synthesized starting from 4-allylanisole and perfluorohexyl iodide.The monomers 4a and 4b were then copolymerized with octadecyl acrylate and 2-hydroxyethyl acrylate by emulsion polymerization to give copolymers PFA 1 and PFA 2 respectively.The co-polymers were characterized by FT-IR and their heat stability was measured by TGA.The surface properties of PFA 1 and PFA 2 were studied by applying on cotton fabrics.The treated cotton fabrics showed good water-repellent property,and the contact angles for water reached 142° for PFA 1 and 136° for PFA 2.

Synthesis and Application of a Novel Perfluorooctylated Citric Acid

A novel perfluorooctylated citric acid was synthesized successfully via allylation of triethyl citrate followed by perfluorocctylation, reduction and hydrolysis. The fabrics treated with this compound showed good oil repellent and moderate water repellent properties： the oil repellent rating and the water repellent score were 6 and 80 respectively. Even after 10 washing cycles, the repellent properties were kept at the same level. The finished fabrics also showed some wrinkle-resistant properties, and the dry wrinkle recovery angle was increased by 53° compared with untreated fabrics. The critical surface energy of the treated fabric surface was 20±1 mN/m. This multifunctional compound also showed good water solubility, which would be beneficial for the environmental protection.

A slippery hydrogel coating with durable oil-repellent property and self-regeneration capacity

Traditional lubricant impregnated surfaces usually required fluorinated lubricants to achieve slippery oil repellency, but the lubricants infused were expensive and toxic and also suffered from limited stability because of their migrating, evaporating, and leaking during use. Herein, to address this issue, we fabricated a durably fluorine-free slippery oil-repellent hydrogel coating using water as the lubricant. Due to its enhanced water-binding affinity, water could wet the hydrogel completely and form a hydrated-water layer on the surface. The hydrated water layer could act as a lubricant to repel foreign oils, which allowed the hydrogel to display slippery oil-repellency in air, exhibit superoleophobicity underwater, and resist oil fouling upon oil immersion.The hydrogel kept its oil-repellent properties after mechanical tests as well as thermal and freezing treatments,demonstrating its durability. Thanks to its moisture absorption, the water lubricant layer could self-regenerate upon the lubricated water layer depletion through exposure to a humid environment. Exploiting it is water-attracting and oil repellency, the hydrogel coating was demonstrated as a versatile platform for oil/water separation, polymer/water separation, drag-reduction, and antifogging.

Effect of Sequence Structure on Wetting Behaviors of Fluorinated Methacrylate Polymers Based on Perfluorohexylethyl Methacrylate and Stearyl Acrylate

Due to the non-crystalline properties of short chain perfluoroalkyl groups, using short chain perfluoroalkyl to stabilize low surface free energy polymers has been a challenging task. In this study, we prepare a series of random copolymers poly（perfluorohexylethyl methacrylate）-co-poly（stearyl acrylate） （P13FMA-co-PSA） and block copolymers poly（perfluorohexylethyl methacrylate）-b-poly（stearyl acrylate） （P13FMA-b-PSA）, and systematically investigate the effects of the sequence structure and the content of 13FMA of the fluorinated copolymers on surface free energy and surface reorganization. Static/dynamic contact angle goniometry and water/oil repellency analyses demonstrate that the random polymer P13FMA-co-PSA could not achieve low surface free energy and low surface reorganization at the same time. In contrast, for the block copolymer P13FMA-b-PSA, both low surface free energy and low surface reorganization are acquired simultaneously. The results of X-ray photoelectron spectroscopy （XPS）, dynamic contact angle goniometry and differential scanning calorimetry （DSC） reveal the above-mentioned properties. The consecutive 13FMA segments improve the surface fluorine density, while the consecutive SA chains enhance the crystallinity of the SA segments, and further hinder the surface reorganization of the perfluoroalkyl groups. Therefore, P13FMA-b-PSA exhibits a higher utilization efficiency of fluorine atoms and a better structural stability than P13FMA-co-PSA.