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•Phthalocyanine-zirconium polyphosphazene functionalized BP was obtained by crosslinking reaction.•BP-ZrPZN effectively reduced the total smoke release decreased by an impressive ...62.7 %.•BP-ZrPZN can comprehensively improve the fire safety and mechanical properties of EP.
The existence of lone pair electrons on the surface of black phosphorus (BP) is a good electron acceptor, which has good structural stability when it forms new electron donor-electron acceptor pairs when combined with electron donators such as phthalocyanine. In order to bond functional groups available for reaction on the surface of BP, the lamellae group density was increased by functionalizing BP with benzoic acid diazonium salt, and then the carboxylated BP was covalently grafted with phthalocyanine zirconium, and finally the phthalocyanine-zirconium polyphosphazene functionalized BP (BP-ZrPZN) was obtained by crosslinking reaction. Subsequently, BP-ZrPZN was added into the EP matrix as nano filler to form the reinforced system. The results showed that the thermal stability and fire safety of EP composites containing 2 wt% BP-ZrPZN were significantly improved. The peak heat release rate and total heat release rate were reduced by 56.8 % and 54.1 %, respectively, and the limited oxygen index was up to 33 % and UL94 value was V-0. In addition, the presence of BP-ZrPZN greatly improved the ability of BP to inhibit toxic smoke. The total smoke yield of EP composites decreased by 62.7 %. The tensile strength and impact strength increased by 36.1 % and 50.6 % respectively. Therefore, the functional strategy of phthalocyanine in this work will provide a reasonable and feasible way to optimize the flame retardancy and smoke suppression effect of BP.
Azo dyes, compounds having double bond linkage between two nitrogen atoms, are widely found as a main scaffold in a massive library of organic species that exhibit promising industrial and biological ...properties. Due to the numerous potential applications accredited to the azo function, there has been a significant surge in designing novel azo dyes and introducing advanced synthetic routes for their preparation, as well as investigating their diverse properties and seeking potential new applications for this class of compounds. This systematic review contains two parts and is set apart from the classic azo reviews in several aspects. The first part focuses on the biological affinities of azo dyes, while the second part covers the industrial applications of these molecules. In this review, we consolidate and highlight the significant applications of novel azo dyes in biological as well as in industrial fields. It is expected that this review will be helpful in future research to develop more potent multifunctional azo dyes.
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•Azo dyes represent the largest production volume of dye chemistry.•They are considered as fascinating motifs in organic chemistry.•They gained massive attraction due to their versatile bio- and industrial applications.•Substitution effect on the SAR was established according to IC50 values.•The future perspectives of azo dyes were also pointed out.
This study has designed an efficient stepwise reaction to produce some new pyrazoline derivatives bearing azo and benzyloxy linkages. The reaction was initiated by diazotizing p-aminocetophenone with ...2,6-dichlorophenol to give azo compound (1), which was further reacted with benzyl bromide producing the efficacious core material azo-benzyloxy acetophenone(2). This study has designed an efficient stepwise synthesis to produce some new pyrazoline derivatives that contains azo and benzyloxy linkages. The Synthesis route was initiated by diazotizing p-aminocetophenone with 2,6-dichlorophenol to give azo compound (1), which was then reacted with benzyl bromide producing the efficacious core material azo-benzyloxy acetophenone (2). Moreover, compound (2) was treated with a series of substituted benzaldehydes to form intermediate chalcone derivatives (3a-j) which were then treated with phenylhydrazine via Michael type addition reaction to form azo-benzyloxy pyrazoline molecules (4a-j). Ultimately, the structures of the synthesized compounds were revealed using spectroscopic techniques: FT-IR, 1H-NMR, 13C-NMR, and 13C-DEPT-135 spectra. Antimicrobial activities were screened for synthezied Azo-chalcones and Pyrazolines against S.aureus as gram-positive and E.Coli as gram-negative in comparison to a standard antibiotic drug Azithromycine
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•Bi-functional magnetic GO adsorbents with ion selectivities were developed.•Magnetite nanoclusters were grown in-situ on GO oxygenous groups.•Crown ethers as ligands were covalently ...grafted via linkers on GO backbone.•Magnetic GO tethered with 12CE4 was highly effective and selective towards Li+.•Wide selection of CE decorated magnetic GOs were fabricated for various applications.
Metal ions (Mn+) in water are considered as environmental pollutants, as industrial impurities or as potential secondary sources for valuable metals. Increasing generation of complex feed streams has raised the need for more specialized adsorbents that could preferentially capture the target Mn+. While graphene oxide (GO) is an effective adsorbent, its indiscriminate sequestration negatively affects its selectivity. To meet the growing demand for more Mn+-selective materials, GO adsorbents with dual features of ion recognition and magnetic responsiveness were developed. The bi-functional GOs were fabricated by in-situ nucleation of Fe3O4 nanoclusters on GO oxygenous groups and by direct grafting of ethynylbenzene linkers on its backbone, which served as tethering sites for the macrocyclic crown ether (CEs) ligands with tunable Mn+ affinities (i.e. CE@Fe3O4-rGO). As proof-of-concept, 12CE4@Fe3O4-rGO was proven highly selective for Li+ capture, achieving α = 367–14,513 against Na+, K+, Mg2+, Ca2+ in seawater. Its Langmuir-type Li+ adsorption achieved nearly ~100% 12CE4 utilization (1.03 mmol g−1 CE loading). Its pseudo-second uptake rate demonstrated its rapid Li+ capture. 12CE4@Fe3O4-rGO is water-dispersible, magnetically retrievable, and recyclable with consistent Li+ uptake performance. By replacing the CEs with aza15CE5, aza18CE6 and dibenzo-24CE8, three more types of CE@Fe3O4-rGOs (1.24–1.71 mmol CE g−1) were successfully synthesized with varying affinities towards heavy metals, radionuclides and alkali metal ions. These findings highlight the versatility of the proposed technique in producing a wide selection of CE@Fe3O4-rGOs which can be used for selective Mn+ capture in various application for water decontamination, salts removal, and resource recovery.
Designing a realistic structure for transition metal oxides (TMOs) with high specific capacity and good stability is a critical challenge for the development of lithium-ion batteries (LIBs). Herein, ...we report an effective strategy to fabricate sulfonated carbon nanotubes (SCNT) chained Fe3O4 nanoparticles (SCNT/Fe3O4). Compared with acidized carbon nanotubes (CCNT), the nondestructive preparation process of SCNT made it retain high electron conductivity and acquired larger length-diameter ratio. The SCNT/Fe3O4 used as anode material delivered a high reversible capacity (674 mAh g−1 at 500 mA g−1 after 100 cycles) and excellent rate capability (402 mAh g−1 at 2 A g−1 after 200 cycles). The excellent performance may be related to the faster electron transmission network and the more stable three-dimensional framework provided by SCNT. This work presents an approach to fabricate high-performance TMO-based composites for LIBs.
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•The obtained SCNTs maintained the tubular structure of CNT and had active sites for interaction with Fe3+.•The Fe-MOF transformed into octahedrons and SCNTs were embedded in the octahedrons.•The SCNTs/Fe3O4 not only possessed high specific capacity of Fe3O4,but also obtained good cyclic stability.
Nitrite has posed ubiquitous threats to the environment, human health, and public security because of its crucial role in food processing, construction, farming, and explosive manufacturing ...industries. To achieve accurate, sensitive, and on-site detection of trace nitrite, a colorimetric-fluorescent dual-mode sensing probe with unique photophysical process was designed for ultrasensitive determination of nitrite by precisely adjusting the amino site and significantly influencing the coupling reaction activity. This modulating strategy breaks through the dilemma of azo-product with only colorimetric phenomenon, facilitating the probe, 7-amino-4-methylcoumarin, to maintain a desirable sensitivity with detection limits of 98 nM and 629 nM in fluorescent and colorimetric modes, respectively, as well as an outstanding specificity even in the presence of 15 common anions and interfering substances. The probe was further integrated into a portable sensor by applying a polyvinyl alcohol hydrogel as a loading substrate, which showed superior sensing performances in analyzing nitrite in various real samples with visualized, anti-interferent, and dual-mode responses. Consequently, the present reaction-site modulation strategy would provide a general reference for ultrasensitive, on-site, and visual detection of nitrite, and it can be broadly applied in environmental monitoring and food safety assessment.
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•Fluorescent and colorimetric dual-mode coumarin probe for nitrite sensing.•One probe with diazotization and coupling sites for one-step reaction.•Intermolecular charge transfer in twisted azo-product induced PL quenching.•PVA hydrogel-based sensor for sensitive and specific on-site detection.
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•Methanobactin is a fluorescent molecular peptide obtained by fermentation.•Methanobactin and gold nanoparticles form Mb-AuNPs fluorescent probe through Au-S.•The detection is based ...on the diazo coupling reaction-triggered intensity change.•The method exhibits good selectivity and reliability.•The method can be used for detection of nitrite in actual food samples.
Nitrite ions are important markers threatening humans and environmental security. A highly selective method for rapid detection of nitrite needs to be developed. Herein, a novel and rapid fluorescence method for nitrite determination is established on the basis of diazotization-coupling reaction of methanobactin (Mb) extracted by Methylosinus trichosporium OB3b with nitrite on the fluorescence. In the presence of gold nanoparticles (AuNPs), the fluorescence of AuNPs was strongly quenched by the Mb because the sulfhydryl or amino structures on the surface of Mb could be bound to the surface of AuNPs by forming Au-S or Au-N bonds. Upon addition of nitrite, the Mb easily reacts with nitrite to form azo products in the acidic medium. Then, with the increase of nitrite concentration, the Mb-AuNPs fluorescence was gradually recovered, realizing the turn-on fluorescence sensing of nitrite. Under optimal conditions, the proposed method has a good linear relationship with nitrite concentration in the range of 0–8.0 μM and 8.0–50.0 μM, and the detection limit is 16.21 nM. In addition, satisfactory results were obtained for nitrite analysis using milk, ham sausage and leaf mustard as real samples, which demonstrated that the method as-developed would have great practical application prospects.
