Unexpected superhydrophobic polydopamine on cotton fabric

https://doi.org/10.1016/j.porgcoat.2020.105777Get rights and content

Highlights

  • Unexpected superhydrophobic polydopamine has been generated on the cotton fabric via a common deposition process.

  • The mussel inspired polydopamine is generally hydrophilic.

  • The durability of the surface superhydrophobicity against mechanical and / or chemical impacting is impressive.

Abstract

Polydopamine (PDA) is the mussel-inspired coating with the outer-exposed functional groups such as amine as well as hydroxyl and widely used in the field of surface modification. Due to the polar functional groups, the PDA is generally hydrophilic. Herein, for the first time, we have unexpectedly fabricated a durable superhydrophobic PDA coating via a quite normal deposition on the cotton fabric but failed on other fabrics such as linen and silk. This suggests that such a cotton fabric might induce the exposing of the hydrophobic benzene moiety of PDA and endow the surface non-wettability, which is further enhanced by the rough surface structures of the fabric. In addition, the durability of the surface superhydrophobicity against mechanical impacting (abrasion), chemical impacting (immersion in acid, alkali, and boiling water), and a combining of chemical / mechanical impacting (laundering and ethanol ultrasonication) has also been assessed. The behaviors are comparable or even superior to the typical reported results in the references except for the immersion test in alkali due to the inherent instability of PDA in alkali solution. A sample application study case is also presented to demonstrate its capabilities in the recyclable oil / water separation.

Introduction

Generally, surface with excellent water repellent property embodied in its static contact angle higher than 150° and sliding angle lower than 10° is defined as superhydrophobic surface [[1], [2], [3]]. In recent decades, based on the distinguished Wenzel and Cassie-Baxter theories [4,5], plenty of ways have been developed to fabricate superhydrophobic materials such as etching [6], chemical vapor deposition [7], laser writing [8], electrospinning [9], hydrothermal treating [10], electro-deposition [11], etc. Moreover, this kind of functional surface has been applied in various fields such as self-cleaning [[12], [13], [14]], drag-reduction [15], anti-corrosion [16], anti-icing [17], oil / water separation [18], etc. Among the vast amount of superhydrophobic materials, the superhydrophobic fabric fabricated via different method including grafting [22,26], mineralization [24], spray [27], and cross-linking [28] especially attracts lots of attention due to its close relation to our daily life [[19], [20], [21], [22], [23], [24], [25], [26], [27], [28]].

Simultaneously, mussel-inspired chemistry, especially the deposition of polydopamine (PDA), has been used as a new technique in the surface modification [[29], [30], [31], [32], [33], [34], [35], [36]]. It is worth mentioning that PDA tends to show its hydrophilia with the typical static contact angle of ca. 50° on a wide range of planar substrates such as polymer (polytetrafluoroethylene, polycarbonate, nitrocellulose), oxide (SiO2, TiO2) and metal (Cu, Au) [29]. Under the magnification effect of surface roughness according to the Wenzel theory [4], even superhydrophilic nature was endowed on the porous membrane such as polyvinylidene fluoride [37], polypropylene [38], and polyethyleneterephthalate [39] once modified with PDA.

By simultaneous co-depositing or subsequent surface grafting with other hydrophobic chemicals, the PDA-based coating becomes hydrophobic or even superhydrophobic. Such co-deposition and surface modification are generally based on the catechols existed in PDA which can react with thiols and amines via Michael addition reactions [29]. For example, Chen et al. [40] and Xu et al. [41] fabricated superhydrophobic thiol-textiles via simultaneous co-deposition with octadecanethiol and subsequent surface grafting with perfluorodecyl mercaptan, respectively. In addition, Fu et al. [42] developed the technique of co-deposition of PDA with folic acid and prominent superhydrophobicity was achieved after further modifying with stearylamine.

Herein, for the first time, via a simple one-step deposition of PDA without any further surface modification or co-deposition with any other low-face-energy molecules, superhydrophobic cotton fabric was unexpectedly fabricated. Moreover, the so-obtained superhydrophobic sample showed excellent durability against acid, boiling water, laundering, abrasion, ultrasonic oscillation in ethanol solution. To reveal its potential application, the superhydrophobic fabric was used for oil / water separation, which has been a hot research topic these years [[43], [44], [45], [46], [47], [48], [49]]. The results demonstrate that superhydrophobic fabric keeps excellent performance, such as high flux, high separation efficiency, and good recyclability, in the process of oil / water separation.

Section snippets

Materials and chemicals

Cotton fabrics (woven with the average thickness of 0.54 mm and the areal weight of 367.83 g/m2; the warp and weft ends per centimeter are 15 and 10, respectively) were purchased from a local store. Anthrone (C14H10O, >98%) was purchased from Solarbio. Dopamine hydrochloride (DA, 98.5 %) and tris(hydroxymethyl)aminomethane (TRIS, 99.8 %) were purchased from Sigma-Aldrich. Anhydrous copper sulfate (99 %), hydrogen peroxide (30 %) and H2SO4 (98%) were purchased from Sinopharm Chemical Reagent

Surface wettability

The surface appearance as observed by naked eyes and FE-SEM is shown in Fig. 2. The pristine cotton fabric is white (Fig. 2-a1) and the fibers are smooth (Fig. 2a2, a3). Once PDA is deposited thereon, the sample turns to brown and the aggregates are observed. As the deposition time prolonging, the PDA sample becomes darker (Fig. 2b1–e1) and the aggregates are more densely distributed (Fig. 2b2–e2). These analyses suggest that, as the deposition time prolonging, more PDA clusters are formed on

Conclusion

For the first time, we have unexpectedly fabricated a durable superhydrophobic cotton fabric via a simple deposition of polydopamine (PDA) and given a possible explanation for the superhydrophobicity. Moreover, the breakdown of its superhydrophobicity against mechanical impacting (abrasion), chemical impacting (immersion in acid, alkali, and boiling water), and a combining of chemical / mechanical impacting (laundering, ethanol ultrasonication) has been assessed. Except for the immersion test

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

CRediT authorship contribution statement

Junfei Ou: Conceptualization, Methodology, Software. Ji Ma: Writing - original draft. Fajun Wang: Data curation, Writing - original draft. Wen Li: Supervision. Xinzuo Fang: Investigation. Sheng Lei: Software, Validation. Alidad Amirfazli: Conceptualization.

Acknowledgements

The authors acknowledge with pleasure the financial support of this work by the National Natural Science Foundation of China (Grant No. 51563018), Qing Lan Project of Jiangsu Province and the Natural Science Foundation of Jiangsu Province (BK20191034).

References (55)

  • T.A. Khattab et al.

    Development of durable superhydrophobic cotton fabrics coated with silicone/stearic acid using different cross-linkers

    Mater. Chem. Phys.

    (2020)
  • Q.F. Fu et al.

    A facile and versatile approach for controlling electroosmotic flow in capillary electrophoresis via mussel inspired polydopamine / polyethyleneimine co-deposition

    J. Chromatogr. A

    (2015)
  • L. Chen et al.

    A facile method to mussel-inspired superhydrophobic thiol-textiles @ polydopamine for oil/water separation

    Colloids. Surf. A

    (2018)
  • Z. Xu et al.

    Fabrication of polydopamine-coated superhydrophobic fabrics for oil / water separation and self-cleaning

    Appl. Surf. Sci

    (2016)
  • J. Ou et al.

    Microtribological and electrochemical corrosion behaviors of polydopamine coating on APTS-SAM modified Si substrate

    Appl. Surf. Sci.

    (2009)
  • S. Kim et al.

    Stability-enhanced polydopamine coatings on solid substrates by iron (III) coordination

    Prog. Org. Coat

    (2014)
  • F. Xia et al.

    Bio-inspired, smart, multiscale interfacial materials

    Adv. Mater.

    (2008)
  • S. Wang et al.

    Bioinspired surfaces with superwettability: new insight on theory, design, and applications

    Chem. Rev.

    (2015)
  • G. Wen et al.

    Biomimetic polymeric superhydrophobic surfaces and nanostructures: from fabrication to applications

    Nanoscale

    (2017)
  • R.N. Wenzel

    Resistance of solid surfaces to wetting by water

    Ind. Eng. Chem.

    (1936)
  • A.B.D. Cassie et al.

    Wettability of porous surface

    Trans. Faraday Soc.

    (1944)
  • B.T. Qian et al.

    Fabrication of superhydrophobic surfaces by dislocation-selective chemical etching on aluminum, copper, and zinc substrates

    Langmuir

    (2005)
  • Y. Lee et al.

    Superhydrophobic coatings bio-inspired self-healing superhydrophobic coatings

    Angew. Chem. Int. Ed.

    (2010)
  • S. Yang et al.

    Ultrafast nano-structuring of superwetting Ti foam with robust antifouling and stability towards efficient oil-in-water emulsion separation

    Nanoscale

    (2019)
  • D. Wang et al.

    In situ hydrothermal synthesis of nanolamellate CaTiO3 with controllable structures and wettability

    Inorg. Chem.

    (2007)
  • B. Wang et al.

    Superhydrophobic copper mesh films with rapid oil/water separation properties by electrochemical deposition inspired from butterfly wing

    Appl. Phys. Lett.

    (2013)
  • Y.F. Si et al.

    Bio-inspired writable multifunctional recycled paper with outer and inner uniform superhydrophobicity

    RSC. Adv.

    (2016)
  • Cited by (21)

    • Development of copper impregnated bio-inspired hydrophobic antibacterial nanocoatings for textiles

      2022, Colloids and Surfaces B: Biointerfaces
      Citation Excerpt :

      Mussel-inspired polydopamine (pDA) is regarded as one of the most versatile materials, and behaves like a universal glue that adheres to both inorganic and organic surfaces [21]. pDA acts as a binder and can bind covalently (as a crosslinking agent) or non-covalently (as in π-π stacking, hydrogen bonding, metal coordination or chelation, and so on) [22]. Iqbal et al. investigated the antibacterial activity of pDA against E. coli using a variety of microscopic techniques to learn more about its potential mode of action in inhibiting E. coli cells [23].

    • Fabric phase sorpitive extraction and passive sampling of ultraviolet filters from natural waters using a zirconium metal organic framework-cotton composite

      2022, Journal of Chromatography A
      Citation Excerpt :

      The decoration of cotton with MOF particles was performed in two steps. The first involved the strong adherence of PDA on the cotton surface by strong covalent bonding via PDA carbon-O-cotton carbon groups (Figure S1) [21]. This step was applied in order to modify the cotton surface with the catechol functional groups of PDA, which enhance the immobilizaton of the MOF [15].

    View all citing articles on Scopus
    View full text