A facile cellulose finishing strategy through in-situ growth of sliver-doped manganese dioxide assisted by amine-quinone for improving indoor living quality.

Nowadays, various harmful indoor pollutants especially including bacteria and residual formaldehyde (HCHO) seriously threaten human health and reduce the quality of public life. Herein, a universal substrate-independence finishing approach for efficiently solving these hybrid indoor threats is demonstrated, in which amine-quinone network (AQN) was employed as reduction agent to guide in-situ growth of Ag@MnO2 particles, and also acted as an adhesion interlayer to firmly anchor nanoparticles onto diverse textiles, especially for cotton fabrics. In contrast with traditional hydrothermal or calcine methods, the highly reactive AQN ensures the efficient generation of functional nanoparticles under mild conditions without any additional catalysts. During the AQN-guided reduction, the doping of Ag atoms onto cellulose fiber surface optimized the crystallinity and oxygen vacancy of MnO2, providing cotton efficient antibacterial efficiency over 90 % after 30 min of contact, companying with encouraging UV-shielding and indoor HCHO purification properties. Besides, even after 30 cycles of standard washing, the Ag@MnO2-decorated textiles can effectively degrade HCHO while well-maintaining their inherent properties. In summary, the presented AQN-mediated strategy of efficiently guiding the deposition of functional particles on fibers has broad application prospects in the green and sustainable functionalization of textiles.

Construction of durable antibacterial cellulose textiles through grafting dynamic disulfide-containing amino-compound and nanosilver deposition.

Cotton textile is very comfortable to wear, and also provides an ideal environment for bacterial propagation, easily causing harm to human health. In order to address this issue, various antibacterial techniques are employed for cotton finishing. However, some processes are complex and involve the use of environmentally unfriendly chemicals. In this work, a durable and efficient antibacterial cotton fabric was prepared via grafting of an amino-compound containing dynamic disulfide bonds, and then in-situ deposition of silver nanoparticles (AgNPs). Briefly, the reactive α-lipoic acid-modified polyethyleneimine (mPEI) was introduced to the cotton fibers via thiol-ene click reaction. Subsequently, the amino groups and dynamically-generated sulfhydryl groups in the mPEI molecules were used to initiate the ultrafast reduction of silver ions without the participation of additional reductant, constructing a stable antibacterial layer on fiber surface. The results reveal that the amino and thiol groups of mPEI could form coordination bonds with the deposited silver nanoparticles, and the antibacterial ability of AgNP@cotton-g-mPEI fabric remains at a high level even after 20 washing cycles. After 30 min of contact with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), the antibacterial rates against both bacteria reached 99.99 %. Meanwhile, the network matrix constructed by the recombination of the dynamic disulfide bonds in mPEI endows the cotton fabric with detectable wrinkle resistance and encouraging anti-ultraviolet effect. The present work provides a novel alternative for preparation of durable and efficient antibacterial textiles.

HRP-catalyzed grafting of MXene@PGA to silk fibers for visualization of dual-driven heating smart textile.

MXene-based functional textiles have been widely studied and applied in many fields. However, the service stability of MXene combined with textile substrates in the environment is far from ideal, which makes its practical application a great challenge. Here we introduced gallic acid (GA), as natural reactive polyphenol compound to silk fibers through enzymatic polymerization, which significantly improved the durability of its conductivity. The small molecules of GA can covalently bind to the titanium atoms on the MXene nanosheets, and the tyrosine residues from silk fibroins can be enzymatically oxidized by horseradish peroxidase (HRP) and further coupled with GA simultaneously, thus forming a covalent cross-linked network on the fiber surfaces. Furthermore, the durable MXene-based textile was used to manufacture smart dual-driven thermal devices with temperature monitoring, which can judge the real-time temperature during heating by changes in its apparent color. More importantly, the textile with smart temperature visualization also offers good EMI shielding and superior UV resistance, while retaining its inherent moisture-wicking, breathable and softness. The present work provides a new insight for the preparation of MXene-based multifunctional textile, and the smart visualization of dual-driven heating shows promising applications in practical personal thermal management.

Sensitive Micro-Breathing Sensing and Highly-Effective Photothermal Antibacterial Cinnamomum camphora Bark Micro-Structural Cotton Fabric via Electrostatic Self-Assembly of MXene/HACC.

Natural fabrics are gradually becoming the ideal substrate for flexible smart wearable devices due to their excellent moisture absorption, softness, and skin-friendliness. However, the bonding fastness of the conductive layer and the corresponding durability during service have not yet been well satisfied. In this report, we successfully prepared a smart wearable multifunctional protective cotton fabric with microbreathing monitoring and rapid-photothermal antibacterial abilities of Cinnamomum camphora bark microstructure, by combining chitosan quaternary ammonium salt (HACC) with MXene nanosheets through electrostatic self-assembly. Impressively, MXene nanosheets and HACC established a strong interaction using the electrostatic attraction, endowing the fiber surface with ordered nanosheets. Meanwhile, the fabric decorated with MXene/HACC retains its original characteristics of outstanding breathability and softness, and its conductivity exhibits noticeable stability in terms of resistances to oxidation, washing, various solvents, and long-term bending cycles. On the basis of the principle of adsorption and release of water molecules in the MXene multilayer structures, the MXene/HACC fabric could accurately monitor the physiological health activities of users according to their breathing frequency and depth. Benefiting from the local surface plasmon resonance (LSPR) effect, the MXene/HACC shows encouraging photothermal conversion ability, photothermal stability under long time irradiation, washing resistance, and cycle stability. In addition, the fabric achieved an antibacterial efficiency of nearly 100% against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus within 5 min under an irradiation intensity of 400 mW/cm2. More importantly, after 10 washes, the antibacterial efficiency against the two bacteria could still reach 99.975% and 99.98%, respectively. This multifunctional protective MXene/HACC cotton fabric is expected to play a unique role in the new generation of smart wearable microbreathing sensing and against to bacterial attack, and shows a broad application prospect.

Developing a Multifunctional Silk Fabric with Dual-Driven Heating and Rapid Photothermal Antibacterial Abilities Using High-Yield MXene Dispersions.

Two-dimensional material titanium carbide (Ti3C2Tx MXene) has been widely used for building diverse functional materials; however, the disadvantages of unsatisfactory yield and low concentration during the preparation process generally limit its large-scale promotion. In the present work, an MXene dispersion with enhanced yield (90%), high concentration (45 mg/mL), and excellent dispersibility was successfully prepared. Subsequently, the active MXene nanosheets were effectively in situ deposition onto the silk fiber by means of dip-coating, relying on van der Waals forces and hydrogen bonds. The obtained MXene-decorated silk fabric (MXene@silk) exhibits satisfactory electrical conductivity (170 mS/cm), excellent photothermal and electrothermal conversion properties, especially dual-drive energy conversion, rapid thermal responses, and long-term functional stability. Furthermore, UV protection factor of the fabric, and its antibacterial efficiency against Gram-negative Escherichia coli (E. coli) within 20 min of contact reach over 110 and 99%, respectively, demonstrating remarkable UV resistance and rapid photothermal antibacterial ability. Meanwhile, the fabric of MXene@silk still retains the original characteristics of breathability, softness, and skin-friendly properties compared to the untreated. The multifunctional fabric constructed through a facile and high-yield strategy shows a noticeable potential applying to smart textiles to meet people's multipurpose needs in the future.

Rapid Antibacterial Effects of Silk Fabric Constructed through Enzymatic Grafting of Modified PEI and AgNP Deposition.

Enzymatic antibacterial finishing is an eco-friendly alternative to develop functional silk-based materials. However, the low accessibility of tyrosine residues distributed in fibroin chains restricts the laccase-mediated functionalization of silk fibers (SF). To address this issue, a highly reactive p-hydroxyphenylacetic acid-modified polyethyleneimine (mPEI) was enzymatically grafted onto fibroin using laccase, aiming at constructing an antibacterial matrix of mPEI on the fiber surface. Subsequently, in situ deposition of silver nanoparticles (i.e., AgNPs) into the newly built mPEI network was performed to form a rapid antibacterial layer. The results indicated that laccase efficiently catalyzes the mPEI coupling, the zeta potential of SF-g-mPEI increases from -32 to 21.70 mV, and the silver content reaches 1.81% after AgNP embedment. Based on the combined two-step treatments, the obtained silk fabric exhibited excellent antibacterial abilities against two bacteria, including Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The antibacterial rates of both bacteria reached 99.9% within 30 min of contact, remaining over 99.9% within 18 h of contact even after washing 10 times. The present work provides an enzyme-mediated method for construction of silk fabric with durable and rapid antibacterial activity.

Dopamine Grafted Iron-Loaded Waste Silk for Fenton-Like Removal of Toxic Water Pollutants.

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 10-40 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.

Fabrication of superhydrophobic caffeic acid/Fe@cotton fabric and its oil-water separation performance.

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.

Dopamine-Dyed and Functionally Finished Silk with Rapid Oxidation Polymerization.

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·L-1, and that of Fe3+ was 2 mmol·L-1; the total reaction time was 50 min and reacted at 50 °C; 9 mmol·L-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 >30 and UVA <4%. The water contact angle of treated fabric attained 142.6°, 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.