Flame retardant cotton fibers produced using novel synthesized halogen-free phosphoramide nanoparticles

Chitosan-based aerogels: A new paradigm of advanced green materials for remediation of contaminated water

Chitosan (CS) aerogels are highly porous (∼99 %), exhibit ultralow density, and are excellent sorbents for removing ionic pollutants and oils/organic solvents from water. Their abundant hydroxyl and amino groups facilitate the adsorption of ionic pollutants through electrostatic interaction, complexation and chelation mechanisms. Selection of suitable surface wettability is the way to separate oils/organic solvents from water. This review summarizes the most recent developments in improving the adsorption performance, mechanical strength and regeneration of CS aerogels. The structure of the paper follows the extraction of chitosan, preparation and sorption characteristics of CS aerogels for heavy metal ions, organic dyes, and oils/organic solvents, sequentially. A detailed analysis of the parameters that influence the adsorption/absorption performance of CS aerogels is carried out and their effective control for improving the performance is suggested. The analysis of research outcomes of the recently published data came up with some interesting facts that the unidirectional pore structure and characteristics of the functional group of the aerogel and pH of the adsorbate have led to the enhanced adsorption performance of the CS aerogel. Finally, the excerpts of the literature survey highlighting the difficulties and potential of CS aerogels for water remediation are proposed.

Phosphamide-Based Washing-Durable Flame Retardant for Cotton Fabrics

A formaldehyde-free reactive flame retardant, an ammonium salt of triethylenetetramine phosphoryl dimethyl ester phosphamide phosphoric acid (ATPEPDPA), was synthesized and characterized using nuclear magnetic resonance (NMR). Fourier transform infrared spectroscopy test (FT-IR), durability test and scanning electron microscopy (SEM) results suggested that ATPEPDPA was successfully grafted on cotton fabrics through a -N-P(=O)-O-C covalent bond. Moreover, the limiting oxygen index (LOI) value of 20 wt% ATPEPDPA-treated cotton was 44.6%, which met stringent washing standard after 50 laundering cycles (LCs). The high washing resistance of the ATPEPDPA-treated cotton was due to the p-π conjugation between the N atom and the P(=O) group in the flame-retardant molecule, which strengthened the stability of the -N-P(=O)-O-C bonds between ATPEPDPA and cellulose, and the -N-P(=O)-(O-CH3)2 groups in the ATPEPDPA. The cone calorimetric test showed that the treated cotton had excellent flame retardance. In addition, the TG and TG-IR tests suggested that ATPEPDPA performed a condensed flame retardance mechanism. Furthermore, the physical properties and hand feel of the treated cotton were well maintained. These results suggested that introducing -N-P(=O)-(O-CH3)2 and -N-P(=O)-(ONH4)2 groups into ATPEPDPA could significantly increase the fire resistance and durability of cotton fabrics.

Improved cotton fabrics properties using zinc oxide-based nanomaterials: A review

Zinc oxide nanoparticles (ZnO NPs) have gained significant attention in the textile industry for their ability to enhance the physicochemical properties of fabrics. In recent years, there has been a growing focus on the development of ZnO-based nanomaterials and their applications for cotton and other fabrics. This review paper provides an overview of the synthesis and diverse applications of ZnO-based nanomaterials for textile fabrics, including protection against UV irradiation, bacteria, fungi, microwave, electromagnetic radiation, water, and fire. Furthermore, the study offers the potential of these materials in energy harvesting applications, such as wearable pressure sensors, piezoelectric nanogenerators, supercapacitors, and human energy harvesting. Additionally, we discuss the potential of ZnO-based nanomaterials for environmental cleaning, including water, oil, and solid cleaning. The current research in this area has focused on various materials used to prepare ZnO-based nanocomposites, such as metals/nonmetals, semiconductors, metal oxides, carbon materials, polymers, MXene, metal-organic frameworks, and layered double hydroxides. The findings of this review highlight the potential of ZnO-based nanomaterials to improve the performance of textile fabrics in a range of applications, and the importance of continued research in this field to further advance the development and use of ZnO-based nanomaterials in the textile industry.

Fire-Retardant Property of Hexasubstituted Cyclotriphosphazene Derivatives with Schiff Base Linking Unit Applied as an Additives in Polyurethane Coating for Wood Fabrication

A series of new hexasubstituted cyclotriphosphaze derivatives containing Schiff base linkages were successfully synthesized and characterized. The series contains different terminal substituents of pentyl and tetradecyl. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and carbon, hydrogen, and nitrogen (CHN) elemental analysis were used to characterize the intermediates and final compounds, while the thermal stability of the final compounds is evaluated with a thermogravimetric analysis (TGA) test. The final compounds are physically added to the polyurethane coating formulation and then applied to the wood panel using a brush and the compound’s fire-retardant properties are evaluated using the limiting oxygen index (LOI) test. In this research, compound 3b showed good thermal stability compared to compound 3a. In terms of LOI results, polyurethane with an LOI value of 21.90% was employed as a matrix for wood coating and the value increased to 24.90% when this polyurethane is incorporated with 1 wt.% of the compound 3b. The increase in the LOI value indicates that the wood coating containing hexasubstituted cyclotriphosphazene compounds exhibits excellent fire-retardant properties as additives.

Development of Cotton Fabrics via EVA/SiO2/Al2O3 Nanocomposite Prepared by γ-Irradiation for Waterproof and Fire Retardant Applications

Development of cotton fabric (CF) properties using nanocomposites via coating method was of considerable interest for wide applications. This article aims at developing CF properties by coating treatment using ethylene–vinyl-acetate (EVA), silicon dioxide (SiO2), aluminum oxide (Al2O3) nanoparticles and γ-irradiation widely used in waterproof and flame retardant applications. EVA-based nanocomposites, EVA/SiO2, EVA/Al2O3, and EVA/SiO2/Al2O3, were synthesized by γ-irradiation and the highest gel content of 81.2–95.3% was achieved at 30 kGy. The physicochemical properties of EVA-based nanocomposites were characterized by FT-IR, XRD, DSC and SEM techniques. Usage of irradiated EVA and EVA-based nanocomposites for treatment of CF by coating technique was successfully achieved. This technique provides a simple and versatile method leading to excellent uniform and smooth surface morphology without aggregation. The weight gain, mechanical properties, thermal properties, water vapor permeability and flame-retardant properties of the modified CF were evaluated. Moreover, compared with control CF, the resistivity of water absorptivity and hydrophobic property and the thermal stability were gained. The flame retardant properties of CF samples were performed using limited oxygen index (LOI) and vertical burning flame tests. LOI percentages of CF/EVA/SiO2, CF/EVA/Al2O3 and CF/EVA/SiO2/Al2O3 increased to 25.3, 27.5, and 29.3%, respectively. Untreated CF ignited and burned rapidly after 5 s. Meanwhile, the treated CF hold flame resistance properties and the burning time prolonged to 25 s. The results of the treated CF providing revealed hydrophobic and protective capability of the fabrics from being destroyed by burning, and support their further use in waterproof and flame retardant applications of fabrics.

Recent advances in the synthesis and applications of phosphoramides

Phosphoramide, as an important framework of many biologically active molecules, has attracted widespread attention in recent decades. It is not only widely used in pharmaceuticals because of its excellent biological activities, but it also shows good performance in organic dyes, flame retardants and extractors. Thus, it is of great significance to develop effective and convenient methods for the synthesis of phosphoramides. In this review, the recent advancements made in the synthesis routes and applications of phosphoramides are discussed. The synthetic strategies of phosphoramides can be separated into five categories: phosphorus halides as the substrate, phosphates as the substrate, phosphorus hydrogen as the substrate, azides as the substrate and other methods. The latest examples of these methods are provided and some representative mechanisms are also described.

A Review on Synthesis, Structural, Flame Retardancy and Dielectric Properties of Hexasubstituted Cyclotriphosphazene

Hexachlorocyclotriphosphazene is a ring compound consisting of an alternating phosphorus and nitrogen atom with two chlorine substituents attached to the phosphorus atom. The six chlorine atoms attached to this cyclo compound can be substituted with any different nucleophile that leads to changes in different chemical and physical properties. The major topics that were investigated in this research are the flame retardancy and dielectric properties of cyclotriphosphazene compounds. Cyclotriphosphazene compounds have high potential to act as a flame retardant, and this compound consists of two active elements attributed to its high flame-retardant character. This compound also demonstrated good ability as a flame retardant due to its low toxicity and less smoke produced. In addition, cyclotriphosphazene compounds were also investigated for their dielectric properties. Cyclotriphosphazene has high potential in the electrical field since it has dielectric properties that can be widely studied in the investigation of any potential application. This review presented literature studies focused on recent research development and studies in the field of cyclotriphosphazene that focused on synthesis, structural, flame retardancy, and dielectric properties of hexachlorocyclotriphosphazene compounds.

Sustainable Use of Nanomaterials in Textiles and Their Environmental Impact

At present, nanotechnology is a priority in research in several nations due to its massive capability and financial impact. However, due to the uncertainties and abnormalities in shape, size, and chemical compositions, the existence of certain nanomaterials may lead to dangerous effects on the human health and environment. The present review includes the different advanced applications of nanomaterials in textiles industries, as well as their associated environmental and health risks. The four main textile industry fields using nanomaterials, nanofinishing, nanocoatings, nanofibers, and nanocomposites, are analyzed. Different functional textiles with nanomaterials are also briefly reviewed. Most textile materials are in direct and prolonged contact with our skin. Hence, the influence of carcinogenic and toxic substances that are available in textiles must be comprehensively examined. Proper recognition of the conceivable benefits and accidental hazards of nanomaterials to our surroundings is significant for pursuing its development in the forthcoming years. The conclusions of the current paper are anticipated to increase awareness on the possible influence of nanomaterial-containing textile wastes and the significance of better regulations in regards to the ultimate disposal of these wastes.

Facile synthesis of a high efficiency and durability L-citrulline flame retardant for cotton

A novel flame retardant (FR), the ammonium salt of citrulline-penta (methylphosphonic acid) (ACPMPA) based on L-citrulline was synthesized, and its structure was characterized by ¹³C, ¹H, and ³¹P nuclear magnetic resonance (NMR) spectroscopy. The ACPMPA flame retardant molecule contains five ammonium salts of phosphorus acid and one ammonium salt of carboxylic acid, which allowed the covalent attachment of ACPMPA onto cellulose via -P=O(-O-C) and -COOC bonds. The results showed that the treated cotton fabrics had very high flame retardance and excellent durability. The limiting oxygen index (LOI) of cotton fabric treated with 35%-ACPMPA reached 49.2% and only decreased to 34.2% after 50 laundry cycles. Vertical flame tests also demonstrated that the treated cotton fabric acquired good flame retardance. The thermogravimetry (TG) and TG-IR results showed that the treated cotton left more residues and released almost no flammable volatiles at high temperatures. The cone calorimetry results showed that the treated cotton released less heat than pure cotton. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results demonstrated that the structure of the treated cotton fabric was almost unchanged, and no free formaldehyde was detected, indicating that the treated cotton was safe. The treated cotton fabric also retained good tensile strength and whiteness.

Synthesis of novel liquid crystalline and fire retardant molecules based on six-armed cyclotriphosphazene core containing Schiff base and amide linking units

Nucleophilic substitution reaction between 4-hydroxybenzaldehyde and hexachlorocyclotriphosphazene, HCCP formed hexakis(4-formlyphenoxy)cyclotriphosphazene, 1. Intermediates 2a-e was formed from the alkylation reaction of methyl 4-hydroxybenzoate with alkyl bromide which further reduced to form benzoic acid intermediates. Further reaction of 2a-e and other substituted benzoic acid formed 3a-h, which then reduced to give subsequent amines, 4a-h. Other similar reaction was used to synthesis 4i. Condensation reaction between 1 and 4a-i yielded hexasubstituted cyclotriphosphazene compounds, 5a-i having Schiff base and amide linking units, and these compounds consist of different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, carboxy, chloro, and nitro groups, respectively. Compound 5j with amino substituent at terminal end was formed from the reduction of 5i. All the intermediates and compounds were characterized using Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and CHN elemental analysis. Mesophase texture of these compounds were determined using Polarized Optical Microscope (POM) and their mesophase transition were further confirmed using Differential Scanning Calorimetry (DSC). Only compounds 5a-e with alkoxy chains exhibited smectic A phase while other intermediates (1, 2a-e, 3a-h, and 4a-i) and final compounds (5f-j) are found to be non-mesogenic with no liquid crystal behaviour. The confirmation of the identity of the SmA phase was determined using XRD analysis. The study on the structure-properties relationship was conducted in order to determine the effect of the terminal group, length of the chains and linking units to the mesophase behaviour of the compounds. Moreover, the fire retardant properties of these compounds were determined using Limiting Oxygen Index (LOI) testing. Polyester resin with LOI value of 22.53% was used as matrix for moulding in the study. The LOI value increased to 24.71% when this polyester resin incorporated with 1 wt% of HCCP. Generally, all the final compounds showed a positive results with LOI value above 27% and the highest LOI value was belonged to compound 5i with 28.53%. The high thermal stability of the Schiff base molecules and the electron withdrawing group of the amide bonds and nitro group enhanced the fire retardant properties of this compound.

Synthesis of New Star-Shaped Liquid Crystalline Cyclotriphosphazene Derivatives with Fire Retardancy Bearing Amide-Azo and Azo-Azo Linking Units

Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of linking units in the molecules such as amide-azo (6a-j) and azo-azo (8a-j). The homologues of the same series contain different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxyl, carboxyl, chloro, nitro, and amino groups. All the intermediates and final compounds were characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and Carbon, Hydrogen, and Nitrogen (CHN) elemental analysis. Liquid crystal properties for all compounds were determined using polarized optical microscope (POM). It was found that only intermediates 2a-e with nitro and alkoxyl terminal chains showed a smectic A phase. All the final compounds with alkoxyl substituents are mesogenic with either smectic A or C phases. However, other intermediates and compounds were found to be non-mesogenic. The study on the fire retardancy of final compounds was determined using limiting oxygen index (LOI) method. The LOI value of pure polyester resin (22.53%) was increased up to 24.71% after treating with 1 wt% of hexachlorocyclotriphosphazene (HCCP). Moreover, all the compounds gave positive results on the LOI values and compound 6i with the nitro terminal substituent showed the highest LOI value of 27.54%.

Liquid-Crystal and Fire-Retardant Properties of New Hexasubstituted Cyclotriphosphazene Compounds with Two Schiff Base Linking Units

A series of new hexasubstituted cyclotriphosphazene compounds (4a–j) consisting of two Schiff base linking units and different terminal substituents was successfully synthesized and characterized. The structures of these compounds were confirmed using Fourier Transform Infra-Red (FTIR), Nuclear Magnetic Resonance (NMR), and CHN elemental analysis. Polarized optical microscopy (POM) was used to determine their liquid-crystal behavior, which was then further confirmed using differential scanning calorimetry (DSC). Compounds 4a–i with heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, 4-carboxyphenyl, chloro, and nitro terminal ends, respectively, showed the liquid-crystal properties, whereas compound 4j with the amino group was found to be non-mesogenic. The attachment of an electron-donating group in 4j eventually give a non-mesogenic product. The study of the fire-retardant properties of these compounds was done using the limiting oxygen index (LOI). In this study, polyester resin (PE) was used as a matrix for moulding, and the LOI value of pure PE was 22.53%. The LOI value increased to 24.71% when PE was incorporated with 1 wt.% of hexachlorocyclotriphosphazene (HCCP), thus indicating that HCCP has a good fire-retardant properties. The result showed that all the compounds have good agreement in their LOI values. Compound 4i with a nitro terminal group gave the highest LOI value of 28.37%.

Nitrogen and phosphorous doped graphene quantum dots: Excellent flame retardants and smoke suppressants for polyacrylonitrile nanocomposites

Nitrogen (N-GQD) as well as nitrogen and phosphorous co-doped (NP-GQD) graphene quantum dots were demonstrated as novel, low cost, green and highly effective flame retardants and smoke suppressants for polyacrylonitrile (PAN) nanocomposites. The N-GQD and NP-GQD samples were synthesized by hydrothermal method with citric acid as the main reactant. For the first time, the flame retardant and smoke suppressant properties of the NP-GQD were studied. The GQDs were introduced into PAN by solvent blending route. Subsequently, thermal stability, flame retardancy, fire behavior, fire hazard and structure of the residual char were investigated by thermogravimetric analysis (TGA), UL-94 vertical burning test, cone calorimetry, FE-SEM, and Raman spectroscopy. Results showed that both PAN/N-GQD and PAN/NP-GQD nanocomposites had higher flame retardancy and smoke suppressant behavior in addition to lower fire hazard properties than neat PAN. Furthermore, the residual chars for the nanocomposite samples were increased in comparison to the neat PAN. The improvements were even more significant in case of the PAN/NP-GQD due to the synergistic effect of nitrogen and phosphorous. The improvements were mainly ascribed to the ability of the N-GQD and NP-GQD to provide stronger and larger protective char barrier layers, which was even more pronounced in case of the NP-GQD.

Simultaneous fire safety enhancement and mechanical reinforcement of poly(lactic acid) biocomposites with hexaphenyl (nitrilotris(ethane-2,1-diyl))tris(phosphoramidate)

Poly(lactic acid) (PLA) is an important bioplastic polymer with wide engineering applications, but has relatively low tensile strength and high susceptibility to flames. This manuscript reports the synthesis of a new cyclo-phosphorus-nitrogen flame retardant (FR) - hexaphenyl (nitrilotris(ethane-2,1-diyl))tris(phosphoramidate) (HNETP) for concurrent FR and tensile strength enhancement. ¹H, ¹³C Nuclear Magnetic Resonance and Fourier Transform Infra-red spectra showed that HNETP was successfully synthesized. The FR properties of PLA/HNETP composites were investigated, and the peak heat release rate (PHRR) reduced by ˜ 51.3%, total heat released (THR) ˜ 43.1%, and carbon monoxide (CO) production by ˜ 46.5% with 3 wt% HNETP loading. The fire performance index increased by ˜ 65.8%, while the fire growth index decreased by ˜ 56.7%. The tensile strength and the Young's Modulus improved to ˜ 67.4 and ˜ 87.8% respectively. A significant increase in limiting oxygen index (LOI) (32.5%) was attained with a V-0 rating in the vertical burning test. TG-IR study showed considerable reduction in pyrolysis gaseous products by the PLA/HNETP composites compared to PLA. Insignificant changes were observed in the glass transition and the melting temperature of PLA and PLA/HNETP biocomposites.

Sulfur-Based Copolymeric Polyamidoamines as Efficient Flame-Retardants for Cotton

The polyamidoamine derived from N,N'-methylenebisacrylamide (M) and glycine (G), M-G, has been shown to be an effective flame-retardant (FR) for cotton in horizontal flame spread tests (HFST), extinguishing the flame at 5% add-on. Its activity was attributed to its intrinsic intumescence. In vertical flame spread tests (VFST), M-G failed to extinguish the flame even at 30% add-on. Conversely, in VFST, the polyamidoamine derived from M and cystine (C), M-C, inhibited cotton combustion at 16% add-on, but in HFST failed to extinguish the flame below 12% add-on. Its activity was ascribed to the release of sulfur-containing volatiles acting as radical scavengers. In this work, the FR effectiveness of M-Gm-Cn copolymers with different G/C ratio was compared with that of the M-G and M-C homopolymers and of M-G/M-C blends of the same compositions. In HFST, both copolymers and blends extinguished the flame. In particular, M-G50-C50 and (M-G/M-C)50/50 extinguished the flame, even at 7% add-on. In VFST, the copolymers with ≥50% M-C units, similar to M-C, inhibited cotton combustion at 16% add-on. At the same add-on, the M-G/M-C blends failed to extinguish the flame. It may be concluded that, in contrast to blends, copolymers combined the merits of both homopolymers in all tests.

Preparation of Ion-Exchanged TEMPO-Oxidized Celluloses as Flame Retardant Products

Cellulose, as one of the most abundant natural biopolymers, has been widely used in textile industry. However, owing to its drawbacks of flammability and ignitability, the large-scale commercial application of neat cellulose is limited. This study investigated some TEMPO-oxidized cellulose (TOC) which was prepared by selective TEMPO-mediated oxidation and ion exchange. The prepared TOC was characterized by Fourier transform infrared (FT-IR) spectroscopy and solid-state ¹³C-nuclear magnetic resonance (¹³C-NMR) spectroscopy. The thermal stability and combustion performance of TOC were investigated by thermogravimetry analysis (TG), microscale combustion calorimetry (MCC) and limiting oxygen index (LOI). The results demonstrated that the thermal stability of TOC was less than that of the pristine material cellulose, but the peak of heat release rate (pHHR) and the total heat release (THR) of all TOC were significantly reduced. Additionally, the LOI values of all TOC products were much higher 25%. In summary, the above results indicated that the modified cellulose with carboxyl groups and metal ions by selective oxidation and ion exchange endows efficient flame retardancy.

Flame retardant vinylon/poly(m-phenylene isophthalamide) blended fibers with synergistic flame retardancy for advanced fireproof textiles

Superior flame retardant textiles are urgently needed to address high fire and heat risks. This study provides a simple and effective strategy to improve the flame retardancy of textiles through a synergistic effect between the blended fibers, and a system with synergistic in flame retardant vinylon (FRV)/poly(m-phenylene isophthalamide) (PMIA) blended fibers is discovered. The FRV/PMIA 50/50 exhibits a much higher time to ignition and a lower peak heat release rate than those of the neat components, indicating a synergistic flame retardancy between constituents. The corresponding mechanism is explored. The residual char layer formed by blended fibers connects together and keeps the original fiber shape, which acts as a barrier slowing heat transmission and gas diffusion. Concurrently, thermal degradation analysis of blended fibers implies that both components mutually interact with each other, resulting in a higher experimental amount of incombustible gases at an early degradation stage and lower experimental amount of combustible gases at a later degradation stage as compared to the theoretical one. Therefore, the synergistic flame retardancy in FRV/PMIA blended fibers is attributed to the actions in the condensed and gas phases during pyrolysis. This work provides an effective strategy to design fireproof textiles.

ZnO Microstructures as Flame-Retardant Coatings on Cotton Fabrics

In this study, we report a unique strategy that utilizes ZnO and ZnS microparticles and rods as fire-retardant materials when coated onto cotton fabrics. ZnO and ZnO/ZnS microparticles or rods were grown or adsorbed to the surface of cotton fibers. Properties such as heat release rate, total smoke release, and mass loss rate of the materials were tested using a cone calorimeter. ZnO and ZnO/ZnS rods were able to reduce the heat release rate and total smoke release from 118 kW/m² and 18.3 m²/m² to about 70.0 kW/m² and 6.00 m²/m², respectively. The maximum average rate of heat emission and fire growth rate index, which is used to evaluate the fire spread rate, the size of the fire, and the propensity of fire development, were improved with these coatings and indicate that there are potential applications of these materials as fire retardants.

Employing the cyclophosphate to accelerate the degradation of nano-hydroxyapatite/poly(amino acid) (n-HA/PAA) composite materials

Owing to the good degradability and biocompatibility of polyphosphoesters (PPEs), the aim of the current study was to investigate a novel degradable composite of nano-hydroxyapatite/poly(amino acid) (n-HA/PAA) with cyclophosphate (CPE) via in situ melting polymerization to improve the degradation of n-HA/PAA. The structure of each composite was characterized via Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The degradation properties were studied in terms of the weight loss and pH in a phosphate-buffered saline (PBS) solution, while the surface morphology was examined using a scanning electron microscope-energy dispersive spectrometer (SEM-EDS) after soaking the surface in simulated body fluid (SBF). The cell proliferation, cell adhesion, and alkaline phosphatase (ALP) activity were used for the analysis of cytocompatibility. The weight loss results showed that the n-HA/PAA composite was 9.98 wt%, weighed after soaking in the PBS solution for 12 weeks, whereas the nano-hydroxyapatite/polyphosphoester-amino acid (n-HA/PPE-AA) composite was 46.94 wt%. The pH of the composites was in a suitable range between 6.64 to 7.06 and finally stabilized at 7.39. The SEM and EDS results revealed the formation of an apatite-like layer on the surface of the n-HA/PPE-AA composites after soaking in SBF for one week. The cell counting Kit 8 (CCK-8) assay of the cell culture in the leaching liquid of the n-HA/PPE-AA composites exhibited non-cytotoxicity and high-proliferation, and the cell adhesion showed the well spreading and normal phenotype extension of the cells on the n-HA/PPE-AA composites surface. Concurrently, the co-culture results of the composites and cells confirmed that the n-HA/PPE-AA composites exhibited a higher ALP activity. In summary, the results demonstrated that the n-HA/PPE-AA composites had a controllable degradation property, good bioactivity, and cytocompatibility.

Single-faced flame resistance of cotton fabrics modified via mist copolymerization

Mist copolymerization for fabricating single-sided flame retardant cotton fabrics.

Recent Advances for Flame Retardancy of Textiles Based on Phosphorus Chemistry

This paper aims at updating the progress on the phosphorus-based flame retardants specifically designed and developed for fibers and fabrics (particularly referring to cotton, polyester and their blends) over the last five years. Indeed, as clearly depicted by Horrocks in a recent review, the world of flame retardants for textiles is still experiencing some changes that are focused on topics like the improvement of its effectiveness and the replacement of toxic chemical products with counterparts that have low environmental impact and, hence, are more sustainable. In this context, phosphorus-based compounds play a key role and may lead, possibly in combination with silicon- or nitrogen-containing structures, to the design of new, efficient flame retardants for fibers and fabrics. Therefore, this review thoroughly describes the advances and the potentialities offered by the phosphorus-based products recently developed at a lab-scale, highlighting the current limitations, open challenges and some perspectives toward their possible exploitation at a larger scale.