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Inspired by the melanin and marine mussel binders, the super-adhesion polydopamine (PDA) plays a unique role in the surface modification of materials. In this work, dopamine was coated on silk fabric in a short time by rapid oxidative polymerization, and Fe2+ was wrapped by using the reactive groups on the surface of polydopamine (PDA) as a secondary platform. The hydrophobic, flame retardant and UV resistant properties of the treated fabric were investigated. The surface morphology, crystal form, composition and carbon residue morphology of the treated silk fabric were analyzed. The PDA coating and Fe2+ mineralization wrap changed the morphological structure of the silk fabric, giving the fabric superhydrophobicity, flame retardancy and UV shielding ability. In particular, the wrapped Fe2+ mineralization formed micro-nano particles and a rough structure on the surface of silk fibers, endowing silk fabric with superhydrophobicity. The PDA coating also increased the carbonization property of the fabric during combustion. Furthermore, the formation of metal salts by combustion of mineralized materials was helpful to prevent heat and gas sources, thus making silk fabric have good flame retardancy, showing potential applications as multifunctional advanced textiles.

A superhydrophobic caffeic acid/Fe@cotton fabric (CfA/Fe@cotton fabric) was fabricated by a simple, high efficiency and environmentally friendly approach and the polymerization of caffeic acid was catalyzed by laccase. This superhydrophobic cotton fabric and caffeic acid/Fe hybrid particles (CfA/Fe) were characterized by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD) and so on. The results showed that the surface of cotton fiber was coated by CfA/Fe composite deposition film, and the ferrous ions can be reduced to zero valent iron particles with good crystal structure in the aging process of reaction. Compared with pristine cotton fabric, the superhydrophobic cotton fabric exhibited high water contact angle (CA) of about 158°. It could withstand various extreme conditions and 100 cycles of abrasion by friction tester without great changes of CA. In addition, CfA/Fe@cotton fabric had excellent self-cleaning and oil-water separation performance, and the oil separation efficiency was higher than 99%. Even after ten times of reuse, it still remained high efficiency separation ability. Moreover, this method has a certain degree of universality, the CfA/Fe can be deposited on many different substrates to form highly hydrophobic surfaces. This superhydrophobic cotton fabric has potential application value in oil-water separation, and this excellent preparation method also has broad application prospects.

Silk fibroin (SF) has excellent biocompatibility and can be regenerated to obtain diverse materials. However, high brittleness and poor elasticity limit its applications in flexible devices, mainly due to high amounts of β-sheet structures in SF. Herein, a flexible SF aerogel is prepared by coupling polyethylene glycol (PEG) containing double-carboxyl end group with fibroin chains. This is followed by ammonium persulfate (APS)-initiated deposition of polypyrrole (PPy) units onto the scaffold. The bifunctional PEG not only improves the elasticity of SF aerogel, but it also promotes the accumulation of pyrrole cations on the fibroin surface and guides the formation of PPy. Meanwhile, PPy distributed in the SF matrix forms an electrically conductive pathway with an encouraging static conductivity, which is responsive to environmental humidity and external pressure. The sensitivity of the prepared SF-based conductive aerogel as a pressure sensor is much better than those reported in literature. Meanwhile, the stress and resistance show good synchronization during cyclic compressions. The present work provides a promising alternative for the fabrication of fibroin-based flexible and conductive aerogels as highly sensitive pressure sensors.

Dopamine (DA) has excellent adhesion and film-forming property due to its catechol structure. In this work, a non-iridescent structural color film was constructed on silk fabric surface by using film-forming property of dopamine (DA) under static condition. At the same time, copper ions and hydrogen peroxide were introduced to induce rapid polymerization of dopamine, which greatly shortened the time of structural color fabrication. The SEM and AFM tests showed that the colored fabric surface had a double-layer structure, one layer was extremely smooth film, and the other layer under the film was polydopamime (PDA) spherical particles. The structural color of the fabric depended on the thickness of the uppermost film. With the extension of time, the film thickness increased continuously, and the color displayed yellow, red, blue, and green in turn. When the film thickness reached a certain value, the structure color returned to yellow, and the structural color has periodicity. This study provides a simple, green, and effective method using DA to prepare structural color on fabric surface.

Nowadays, more and more attention has been paid to ecological environment problems, and the dyeing and finishing field is no exception. Environmentally friendly dyeing and finishing methods have been extensively studied. Inspired by the bioadhesive force of marine mussels, dopamine (DA) was applied as a dyestuff and investigated in textile dyeing. In this work, dopamine was dyed on silk with a rapid oxidation polymerization in the presence of metal ions (Fe3+) and sodium perborate oxidant (Ox). The polydopamine (PDA) was rapidly deposited on silk fabric and the dyeing process was optimized as follows: the concentration of DA was 2 g&middot, L&minus, 1, and that of Fe3+ was 2 mmol&middot, 1, the total reaction time was 50 min and reacted at 50 &deg, C, 9 mmol&middot, 1 Ox was added at 20 min. The K/S value of the treated silk fabric reached 11.46. The color fastness of dyed fabric to light fastness reached Level 4. The SEM and AFM tests showed that the particles attached to the fabric surface and increased the roughness. The XPS test further proved that polydopamine (PDA) was deposited on the fabric. The treated fabric also had a good anti-UV property with a UPF &gt, 30 and UVA &lt, 4%. The water contact angle of treated fabric attained 142.6&deg, showing better hydrophobicity, and the weft breaking strength was also improved. This environmentally friendly dyeing and finishing method can be applied and extended to other fabrics.

Dispersion of iron was achieved on waste silk fibers (wSF) after grafting of polydopamine (PDA). The catalytic activity of the resulting material (wSF-DA/Fe) was investigated in Fenton-like removal of toxic aromatic dyes (Methylene Blue, Cationic Violet X-5BLN, and Reactive Orange GRN) water. The dye removal yield reached 98%, 99%, and 98% in 10&ndash, 40 min for Methylene Blue, Cationic Violet X-5BLN, and Reactive Orange GRN, respectively. The catalytic activity was explained in terms of the effects of temperature, dyes, and electrolytes. In addition, the kinetic study showed that the removal of dyes followed pseudo-1st order adsorption kinetics. These findings allow envisaging the preparation of fiber-based catalysts for potential uses in environmental and green chemistry.