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A halogen-free and formaldehyde-free phosphorus-nitrogen synergistic flame retardant, pentaethylenehexaamine phosphoramidite ammonium phosphonate (APPEHA), was synthesized and characterized by nuclear magnetic resonance and Fourier-transform infrared (FT-IR) spectroscopy. FT-IR and X-ray photoelectron spectroscopy showed that APPEHA was grafted onto the cotton fabric by P(=O)–O–C covalent bonds. The stability of P(=O)–N and P(=O)–O–C covalent bonds was greatly improved due to the p-π conjugation of phosphamide groups in APPEHA. The cotton fabric treated with 30 wt% APPEHA solution could be washed 50 laundry cycles according to AATCC 61-2013 3 A standard, and the limiting oxygen index only decreased from 48.9 to 42.7%. The results of the vertical combustion test, thermogravimetric (TG) analysis, cone calorimetry and TG-FTIR tests showed that APPEHA promoted the dehydration and charring of cotton fabric and exhibited a synergistic flame-retardant mechanism. Analysis of surface morphology, element content, and crystal structure showed that APPEHA penetrated cotton fabric without greatly affecting the surface morphology or crystal structure of the cotton fiber. After flame retardant finishing, the softness and breaking strength of the cotton fabric were retained. The results showed that APPEHA could be used as a durable flame retardant for cotton fabrics. [ABSTRACT FROM AUTHOR]

Cotton has been widely used in fabrics owing to its good moisture absorption, air permeability, wearing comfort, and biodegradability. However, cotton-based products are always easy to be ignited, and breed bacteria and contamination due to the nature of massive cellulose and pores. In this work, a durable multifunctional coating for cotton fabric with flame retardant, antibacterial, fluorine-free superhydrophobic and self-cleaning properties, flame retardancy-dopamine@silver-polydimethylsiloxane, (FR-PDA@Ag-PDMS), was successfully fabricated on its surface. At first, dopamine (PDA) was deposited on flame-resistance cotton fabric grafted with ammonium vinyl phosphonate (AMVP). Then the antibacterial silver nanoparticles (Ag NPs) were in-situ grown on the fabric surface by reducibility of catechol in PDA. Subsequently, the fabric was coated by PDMS to obtain excellent self-cleaning ability with a water contact angle (WCA) of over 150°. The flame-retardant test results showed the multifunctional coating cotton fabrics obtained the limiting oxygen index value (LOI) of 29.8%, self-extinguishment, lower total heat release, and effective smoke suppression compared with bare cotton. Besides, the coated fabric exhibited excellent antibacterial activity (99.99%) against S. aureus and E. coli. More importantly, under the action of AMVP, PDA@Ag, and PDMS, multifunctional coating cotton fabrics still maintained excellent durability flame retardant, antibacterial, superhydrophobic and self-cleaning performance after 50 standard washing cycles. [ABSTRACT FROM AUTHOR]

Nylon-cotton (NYCO) blend fabrics have been widely used recently; however, they are susceptible to ignition when exposed to flame. Herein, 3-glycidyloxypropyl trimethoxy silane (GPTMS) associated with polyethyleneimine (PEI) and phytic acid (PA) was incorporated on NYCO fabrics through the facile sol–gel and dip-nip-dry method to prepare flame retardant NYCO fabrics with enhanced washing durability. The limiting oxygen index (LOI) value of treated NYCO fabrics was increased from 18.5 to 29.8% and the damaged length was reduced from 30 to 7.5 cm. Cone calorimeter test indicated that the peak heat release rate and total heat release were decreased by 73 and 79% respectively, compared with that of the control NYCO fabrics. The flame retardancy was well maintained and showed self-extinguishing behavior after 20 laundering cycles. The char formation ability was reinforced and the possible flame retardant mechanism was proposed. Moreover, the dermal irritation test showed good biological safety of the fabrics, which were incapable to cause erythema and edema on rabbit skin. This study proposed a feasible method to produce flame retardancy, durability, and bio-safety nylon-cotton blend fabrics by textile finishing. [ABSTRACT FROM AUTHOR]

Development of advanced oil/water separation materials with durability, versatility, and cost-efficiency in a green manner is highly desired yet still challenging. Herein, to address this challenge, we fabricated an advanced platform for oil/water separation using natural corn straw as a raw material. Superhydrophobic corn straw (SHCS) blocks and filter paper with deposited SHCS powder were fabricated by one-step immersion processes that were simple and cost-efficient. The resulting corn straw-based materials kept their superhydrophobicity after immersing in oil, hand-bending test, abrasion with sandpaper, and even 120 h of UV irradiation. The SHCS block was used as an oil sorbent scaffold to absorb oils from oil/water mixtures selectively; while the SHCS powder deposited filter paper was demonstrated as a membrane to separate oil/water mixtures efficiently even in acidic, alkaline, salty, and high-temperature conditions (more than 80 °C). Importantly, these SHCS-based materials retained their high separation efficiency even after 10 cycles of oil/water separation. Superhydrophobic corn straw that can be used as a versatile platform for oil/water separation was fabricated. [ABSTRACT FROM AUTHOR]

In this work, a durable and sunlight-driven self-cleaning superhydrophobic cotton fabric was developed as a multifunctional oil/water separation material. First of all, Ag/AgCl was successfully deposited on the polydopamine modified cotton fabric surface by electrostatic adsorption, then the Ag/AgCl loaded fabric was coated by the polydimethylsiloxane (PDMS) via simple dip-coating method. The as-prepared cotton fabric (PDMS-Ag/AgCl@CF) presented the superhydrophobic property with water contact angle about 155°. Meanwhile, the prepared PDMS-Ag/AgCl@CF exhibited great tolerance and resistance to broad pH and various organic solvents, and it can also withstand 50 cycles of abrasion or 60 min of ultrasound treatment without an apparent decrease of superhydrophobicity, indicating its outstanding mechanical durability. As expected, this durable superhydrophobic fabric can availably separate various oil/water mixtures by gravity-driven force with high separation efficiency (over 97.8%), and it possessed good reusability. Additionally, the PDMS-Ag/AgCl@CF exhibited an outstanding self-cleaning performance under sunlight irradiation, due to visible light photocatalytic performance of Ag/AgCl. Finally, the resultant cotton fabric displayed good antibacterial activity. Therefore, in consideration of its prominent comprehensive performances, it is expected that the PDMS-Ag/AgCl@CF can be used as a promising material for oily water remediation. [ABSTRACT FROM AUTHOR]

Cotton fabric is a prevalent natural textile. The fibers in the cotton fabric are polymers made of thousands of glucose residues linked by glycosidic bonds. Cotton fabric has good air permeability and comfortable softness, which becomes a necessity in life. However, the surface of cotton fabric contains hydrophilic groups such as hydroxyl groups that can absorb moisture. When people wear cotton fabric, it is easy to absorb moisture and breed bacteria, which reduces fabric the performance. Therefore, it is necessary to carry out long-term antibacterial treatment on cotton fabric, which extends the application scope and prolongs the service life of the fabric to a certain extent. Based on this point of view, this paper summarizes the long-acting antibacterial surface construction of cotton fabric by diverse antibacterial materials with assorted ways of action, so that cotton fabric has a better prospect. [ABSTRACT FROM AUTHOR]

The organosilicon quaternary ammonium salt/(zinc oxide@carbon quantum dots) composite material referred to P(DMDAAC-AGE-Si)/(ZnO@CQDs) was prepared with ZnO, glucose and vinyl monomers by situ free-radical polymerization, which was applied into cotton fabrics at different concentrations. It was proved that the antibacterial cotton fabrics had been successfully prepared by FT-IR, SEM, TEM, antibacterial tests (shake flask tests) etc. The antibacterial rate was 98.38% and 99.53% against S. aureus and E. coli, respectively, when the concentration of the treating solution of composites reached to 25 g/L. Even after washing 10 times (equivalent to 50 household washing), the antibacterial rate remained above 89.65% against S. aureus and E. coli. In addition, the hydrophilic properties and air permeability of the treated cotton fabrics were enhanced. [ABSTRACT FROM AUTHOR]

In this paper, a simple and facile polyol sorbitol was employed to design and synthesize a novel flame retardant containing phosphorus and nitrogen by the reaction of sorbitol with phosphoric acid and urea. The obtained sorbitol-based flame retardant was then used to treat lyocell fibers by a pad-dry-cure procedure. Formaldehyde and other harmful substances were not used during the preparation of flame retardant and modified fibers. For this strategy, only water is used as solvent, and the conditions are mild, safe and environmentally friendly. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses show that the sorbitol-based flame retardant was successfully grafted onto lyocell fibers. Scanning electron microscopy analyses show that the surface morphology of the treated fibers remained unchanged. Thermogravimetric analyses imply that the residue of the treated fibers increases considerably. Vertical combustion and limit oxygen index results indicate that the treated fibers possess excellent flame retardant and durable properties. Based on the results of pyrolysis gas chromatography–mass spectrometry, thermogravimetric-infrared and Raman spectroscopy, the flame retardant operates in condensed phase and gas phase during burning of treated fibers. [ABSTRACT FROM AUTHOR]

Abstract: Cellulosic fibers are usually finished with flame retardant via repeated pad-dry-cure processes. The present contribution reports a simple, facile, and one-pot chemical treatment process to access durable flame retardant lyocell fibers by directly immersing the fibers into the solution of a flame retardant ester of 2,2-ethanolamine diphosphoric acid (EADP) and urea for a certain time without using catalyst and cross-linker. As demonstrated, the treated lyocell fibers with grafted EADP show excellent flame retardancy and durability, as evidenced by an increase of limiting oxygen index value up to 37.8% and still 25.6% after 40 washing cycles. The key to success is ascribed to the formation of three dimensional flame retardant structures with EADP. Various analytical techniques, including raman spectroscopy, scanning electron microscope, thermogravimetry, and TG-infrared coupled technique prove that the carbonaceous residue and non-combustion gases were preferably generated during thermal decomposition process of treated fibers. Microcombustion calorimetry results revealed a significant reduction in the peak of heat release rate. The results indicate that EADP is potential for using as an efficient durable flame retardant of lyocell fibers.Graphical abstract: [ABSTRACT FROM AUTHOR]

As a renewable, abundant, and eco-friendly bio-based compound, phytic acid (PA) possesses high phosphorus content, which is a potential flame retardant for cellulosic fibers. Generally, PA is not efficient for cellulosic fibers due to strong acidity that results in greatly reduced strength and lack of soft hand. As proved elsewhere, the compounds with phosphorous and nitrogen was reported to be an efficient flame retardant and exhibited synergistic effect for cellulosic fibers. Therefore, PA was firstly reacted with urea to synthesize a novel green flame retardant containing a high level of phosphorus and nitrogen elements, i.e., phytic acid ammonium, then it was employed for lyocell fibers through pad-dry-cure finishing process. As expected, flame retardancy and durability of finished lyocell fabrics were considerably improved, as evidenced by an increase of limiting oxygen index value up to 39.2% and still 29.7% after 30 laundering cycles. TG-MS and TG-FTIR coupled techniques demonstrate that the formation of carbonaceous residue and non-combustion gases preferably generated during thermal pyrolysis process of finished lyocell fibers. [ABSTRACT FROM AUTHOR]

A novel N-halamine precursor with tertiary amino group (5,5-dimethylhydantoinyl-3-ylethyl)-dimethylamine (DEADH), was synthesized and then covalently bonded onto cotton fabrics modified by 3-chloropropyltrimethoxysilane to form quaternarized N-halamine precursor grafted cotton fabrics which could be transferred to N-halamine structure upon exposure to dilute sodium hypochlorite solution. The grafted cotton fabrics were characterized by FT-IR, X-ray photoelectron spectroscopy, and field emission scanning electron microscope. The antimicrobial test showed that the cotton fabrics grafted with the quaternarized N-halamine were capable of 7-log inactivation of Staphylococcus aureus and Escherichia coli O157:H7 within 1 min of contact time. Very interestingly, it was found that the grafting process and following chlorination had almost no adverse effect on the tensile strength of cotton fabrics. Furthermore, the antimicrobial cotton fabrics exhibited good washing durability and stability. [ABSTRACT FROM AUTHOR]