Search

[Display omitted] • Core-shell NiC 2 O 4 @C/N-doped NiCoZn-LDH(NCO@C/N-LDH) structure was prepared by two-step hydrothermal process. • Carbon and nitride were directly doped into NiCoZn-LDH nanosheets as shell. • The assembled NCO@C/N-LDH//AC devices provided high energy storage capability. Layered double hydroxides (LDHs) are promising cathode materials for supercapacitors due to high theoretical specific capacitance and unique layered structure. Constructing hierarchical core–shell structure for the multicomponent LDHs is an effective strategy to further utilize them. Herein, a novel hierarchical core–shell structure (NCO@C/N-LDH) was fabricated by direct-doping of C and N species into NiCoZn-LDH nanosheets (C/N-LDH) coved on NiC 2 O 4 (NCO) arranged on the nickel foam via two-step hydrothermal method. The NCO as a backbone prevented C/N-LDH nanosheets from collapsing in charge/discharge process, while the C/N-LDH shell provided abundant active sites and exclusive access to electron/ion transport for accelerating the Faradaic reaction kinetics. The optimal NCO@C/N-LDH (2.0) displayed a remarkable electrochemical performance with a high specific charge of 1841.0C/g at 1 A/g and good rate capability. Furthermore, the as-fabricated NCO@C/N-LDH//AC device delivered a high energy density of 56.9 Wh kg−1 at power density of 800 W kg−1. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) are regarded as promising electrode materials for supercapacitors due to their abundance, multiple oxidation states, and high theoretical capacitance. However, the limited active sites and dull reaction kinetics restrict their commercialization. In this work, the 3D hierarchical N-doping ZnCo-LDH array on nickel foam (NF) as an electrode material (N-ZnCo-LDH) was designed and directly fabricated via a hydrothermal method using 2-Methylimidazole as a nitrogen source. Consequently, the N-doping confined the growth of the N-ZnCo-LDH to form ultrathin nanosheets, which exposed more redox reaction active sites and facilitated the charge transfer, resulting in the enhancement in charge storage capacity. As a result, the optimal N (0.5) -ZnCo-LDH achieved a high specific charge of 942.6 C g−1 at 1.0 A g−1, excellent charge-discharge rate property (68.9% retention) and long durability (84.1% after 5 000 cycles). Also, the hybrid supercapacitor (N-ZnCo-LDH//AC) was fabricated employing N (0.5) -ZnCo-LDH as anode and activated carbon (AC) as cathode, which achieved an energy density of 29.2 Wh kg−1 at a power density of 750.0 W kg−1, and excellent cycling stability (84.0% retention after 10,000 cycles), which highlighted the potential of the N (0.5) -ZnCo-LDH electrode material towards practical application of supercapacitors. [Display omitted] • The ultrathin N-doped ZnCo-LDH nanosheets were synthesized using 2-Methylimidazole as nitrogen source. • N-doping confined the growth of the nanosheets, making them smaller and thinner. [ABSTRACT FROM AUTHOR]

A series of novel organic and/or inorganic-intercalated MgAl layered double hydroxides (S x Mo y -LDH) were designed and prepared via calcination-reconstruction, where the organic anion was stearic (S) and inorganic anion was MoO 4 2− (Mo). The intercalation of stearic and/or MoO 4 2− anions into the interlayer galleries of the LDH host layers was controlled by adjusting the mass ratios (x / y) of stearic acid to (NH 4) 2 MoO 4 , in which the stearic-intercalated LDH was obtained above the 1: 1 of the x / y mass ratio, and the MoO 4 2−-intercalated LDH was synthesized below the 1: 1 of the x / y mass ratio. Especially at x / y mass ratio of 1: 1, stearic and MoO 4 2− anions were co-intercalated into the interlayers of the S 1 Mo 1 -LDH to confer excellent flame-retardant properties. The morphology, chemical composition and structure of the as-prepared S 1 Mo 1 -LDH determined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy and energy dispersive spectrometer (SEM/EDS) and thermogravimetry (TG) confirmed the co-intercalation of stearic and MoO 4 2− anions into the interlayer galleries. After adding the S x Mo y -LDH materials into polypropylene (PP) matrix, the flame retardant performance of the PP-composites was significantly enhanced compared with the neat PP. It was also noticed that different interlayer anions could provide different retardant performances, and the stearic-MoO 4 2−-co-intercalated LDH (S 1 Mo 1 -LDH) exhibited the highest thermostability and the best flame retardant performance owing to the synergistic effect of the interlayer stearic and MoO 4 2− anions as well the LDH host layers. Therefore, it was possible to obtain a certain intercalation state of the organic and inorganic anions by modulating the mass ratios (x / y) of organic to inorganic anions. Unlabelled Image • The organic and/or inorganic-intercalated MgAl-LDH, was successfully prepared. • At x/y mass ratio of 1: 1, stearic and MoO 4 2− anions were co-intercalated into the interlayers of the S 1 Mo 1 -LDH. • The S 1 Mo 1 -LDH provided excellent fire resistance to PP matrix owing to the interlayer stearic, MoO 4 2− and LDH. [ABSTRACT FROM AUTHOR]

A facile and low-cost method to prepare novel Ag 2 O-Ag/LDO photocatalysts was demonstrated, where the Ag 2 O/Ag nanoparticles were decorated on the ZnAl oxide (LDO) supports. The LDO supports were obtained by calcining their ZnAl layered double hydroxide precursor (LDH) at different temperatures. The structure, composition, morphology and optical and electrochemical properties of the as-prepared Ag 2 O-Ag/LDO were characterized using various techniques. Under visible light irradiation, the Ag 2 O-Ag/LDO showed higher photoactivity and stability of tetracycline (TC) degradation than pure Ag 2 O-Ag. Especially, the Ag 2 O-Ag/LDO 5 (Ag 2 O-Ag/LDO calcined at 500 °C) had the most excellent photoactivity with the highest rate constant k (0.0242 min−1), suggesting that the photocatalytic activity depended on the calcination temperature. The enhancement of the photocatalytic performance was attributed to the formation of the heterostructure between Ag 2 O/Ag and ZnO, the strong visible-light absorption and outstanding separation efficiency of photoinduced electron-hole pairs under visible light irradiation. • The novel Ag-Ag 2 O/ZnAl-oxide (Ag 2 O-Ag/LDO) photocatalysts were successfully prepared. • The photocatalytic performances depend on the temperature of calcining the support. • The formation of Ag 2 O/ZnO heterojunction promoted the generation and separation of the photogenerated electron-hole pairs. [ABSTRACT FROM AUTHOR]

The menace of antimicrobial resistance continues to increase and hence the need to discover new antibiotics, especially alternative and effective sources such as hybrid organic-inorganic, organic-organic materials, and other combinations. In this study, an antimicrobial hybrid supra-nano material was prepared by the bi-titration synthesis method of chitosan (CS) and ZnAl layered double hydroxide. Fourier-transform infrared spectrometer (FTIR), thermogravimetric and differential thermal gravimetric (TGA/DTG), ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses indicated that the ZnAl/CS hybrid exhibited low crystallinity with high thermal stability. The results of ZnAl/CS characterization showed the characteristic properties of the individual components ZnAl and CS, indicating a successful preparation of the ZnAl/CS hybrid. The antibacterial tests revealed that the ZnAl/CS hybrid possessed an enhanced antimicrobial effect against both Escherichia coli (E. coli, MTCC 739) and Penicilliumcyclopium (P. cyclopium, AS 3.4513). Under the central composite design (CCD) of the response surface methodology (RSM) tool, the parameters of the hybrid synthesis reaction were optimized and the result obtained was as follows: reaction pH was 11.3, reagent Zn/Al ratio was 3.27, and chitosan concentration was 1.07 g/L. After optimization, it was found that the antibacterial activity of ZnAl/CS was strengthened against E. coli as evidenced by a widening of the inhibition zone of about 41.6%. The antibacterial activity of ZnAl/CS was mainly due to the reactivation of the antibacterial activity of CS associated with the release of Zn2+ and Al3+ metal ions in addition to ZnO, Al2O3, and ZnAl2O4 compounds resulting from the method of preparation. [ABSTRACT FROM AUTHOR]

To reduce the charge‐transfer resistance of supercapacitors and achieve faster reversible redox reactions, ternary Ni‐Co‐Fe layered double hydroxide was prepared by using the urea method and then calcined to give NiCoFe oxide (NiCoFeO). To enhance conductivity, a polyaniline (PANI) conductive layer was assembled on the surface of the NiCoFeO particles by in situ oxidative polymerization of aniline monomers. The as‐prepared NiCoFeO/PANI composite was successful employed as a supercapacitor electrode. It was found that the NiCoFeO/PANI composite displayed good cycling stability, with a capacity loss of only 29.54 % after 5000 cycles. Furthermore, the NiCoFeO/PANI composite also exhibited excellent supercapacitor performance, with a high specific capacity of 843 F g−1 at a current density of 2 A g−1, whereas NiCoFeO showed a specific capacity of only 478 F g−1. This result was attributed to the synergistic effect between NiCoFeO and PANI. The facile synthesis strategy and excellent electrochemical performance suggest that NiCoFeO/PANI is a promising economical electrode material for applications in supercapacitors. Composites for supercapacitors: A novel NiCoFeO/polyaniline (PANI) composite was fabricated by in‐situ oxidative polymerization and applied as an electrode material for supercapacitors. The composite displayed excellent supercapacitor performance with a high specific capacity of 843 F g−1 at a current density of 2 A g−1 and good cycling stability, with a capacity loss of only 29.54 % after 5000 cycles (see figure). [ABSTRACT FROM AUTHOR]

Ultrafine Mg/Al hydrotalcite particles (RMAH) were synthesized by co-precipitation in high-gravity environment generated by a rotating packed bed reactor with (NH 4 ) 2 CO 3 as precipitant. Sodium tripolyphosphate modified RMAH (S-RMAH) was investigated as potential flame retardant for polypropylene (PP) material. The RMAH and S-RMAH materials were characterized using XRD, SEM/EDS, TG–DTG, FT-IR, BET, particle size distribution, pH point of zero charge and so on. The S-RMAH particles which were coated by P 3 O 10 5 − possessed smaller particle sizes and narrower sizes range, and their surface property was modified from hydrophilic to hydrophobic nature. As novel functional fire-retarding nanofillers, the RMAH and S-RMAH were used to prepare PP/RMAH and PP/S-RMAH composites, aiming to investigate the effect of the nanofillers on the flammability, compatibility and mechanical properties of PP material. The thermal stability, morphological and flame retardant properties of the two composites were determined by SEM, TGA, LOI and UL94 analyses, and their mechanical properties were also characterized. The results showed that the RMAH and S-RMAH could significantly enhance the thermal stability, flammability and mechanical properties of PP material, and the S-RMAH had better performances as a flame retardant for PP than the RMAH. It offered a new approach to preparing ultrafine hydrotalcite nanoparticles with high anti-flaming performances. [ABSTRACT FROM AUTHOR]

Abstract: Hydrotalcite nanoparticles were synthesized by co-precipitation of aqueous Mg(NO3)2·6H2O and Al(NO3)3·9H2O in the presence of urea and subsequent microwave-hydrothermal treatment. The nanoparticles were activated with saturated aqueous Ca(OH)2, and used to hydrolyze cellulose. A maximum hydrolysis yield of 47.4% with high glucose selectivity (85.8%) was achieved at 423K. The nanocatalyst was stable and leached little as confirmed by ICP, XRD, and neutral effluent aqueous solution after reactions. It can be concluded that hydrotalcite nanoparticles activated with Ca(OH)2 were a highly active, selective and stable catalyst for hydrolysis. [Copyright &y& Elsevier]

A novel and environmentally friendly lignin-based surfactant sodium lignosulfonate (SLS) modified layered double hydroxide (LDH) flame retardant (LDH-LS) was fabricated via co-precipitation method, and subsequently incorporated into polypropylene (PP) matrix to obtain the PP and LDH-LS composites (PP/LDH-LS) by melt blending method. The XRD, FT-IR and XPS results indicated that SLS had successfully modified LDH by adsorbing on the surface of the LDH nanosheet. The WCA and SEM results revealed that the hydrophobic property of LDH-LS had been evidently improved, and it displayed a more homogeneous dispersion than virgin LDH in the PP matrix. Furthermore, cone calorimetry tests (CCT) illustrated that the peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of PP/LDH-LS composites exhibited declines of 62.9%, 25.1%, and 43.3% compared with those of Neat PP, respectively. Besides, the PP/LDH-LS achieved a LOI value of 29.4% and a UL-94 V-0 rating, whereas the PP/LDH showed only a LOI value of 25.2% and a UL-94 V-2 rating at 20 wt% loading. These improvements of flame retardant properties can be attributed to that the well-dispersed LDH-LS and synergistic flame retardancy between LDH and SLS. [ABSTRACT FROM AUTHOR]

To gain high efficiency flame retardant, the twin organic anions intercalated layered double hydroxides (PD x CA y -LDH) were designed and prepared via calcination-reconstruction, where the organic anions were pentaerythritol diphosphate (PD) and cyanuric acid (CA). The morphology, chemical composition and structure of the PD x CA y -LDH materials were characterized, revealed that the PD x CA y -LDH materials were successfully intercalated by the PD and CA anions in single or combining form. The incorporation of the PD x CA y -LDH with ethylene vinyl acetate copolymer (EVA) not only could significantly improve the thermal stability of EVA matrix but also promote the formation of char layer during combustion, owing to the combined advantages of CA, PD and LDH. It was found that the flame retardancy of the PD x CA y -LDH depended on the mass ratio of PD to CA anions, where the PD 7 CA 3 -LDH with a 7:3 mass ratio of PD/CA had the best flame retardancy due to the presence of an excellent char layer. The EVA/PD 7 CA 3 -LDH composite achieved a LOI value of 28.0% and a UL 94 V-0 rating compared with the EVA/LDH composite with 19.5% and a HB rating, and the peak heat release rate (PHRR) and total heat release (THR) decreased to 340.2 kW∙m−2 and 132.7 MJ∙m−2, respectively. These improvements could be attributed to the catalyzing carbonization of the PD and CA to EVA matrix to form more protective char layers. Unlabelled Image • Organic anion-intercalated layered double hydroxides (PD x CA y -LDH) were successfully prepared. • Both organic anions (PD and CA) were inserted into the interlayers of the LDH in respective and/or combining modes. • The effectively-combined effect of PD, CA and LDH could improve the flame retardancy of EVA composites. [ABSTRACT FROM AUTHOR]

Due to the inherent defect of flammability of polypropylene (PP), a novel and highly efficient carbon microspheres@layered double hydroxides@copper lignosulfonate (CMSs@LDHs@CLS) flame retardant was designed and prepared, which was attributed to the strong electrostatic interaction between carbon microspheres (CMSs), layered double hydroxides (LDHs) and lignosulfonate as well as the chelation effect of lignosulfonate on copper ions, and then it was incorporated into the PP matrix. Significantly, CMSs@LDHs@CLS not only observably improved its dispersibility in PP matrix, but also simultaneously achieved excellent flame retardant properties for composites. With the addition of 20.0 % CMSs@LDHs@CLS, the limit oxygen index of CMSs@LDHs@CLS and PP composites (PP/CMSs@LDHs@CLS) reached 29.3 % and achieved the UL-94 V-0 rating. Cone calorimeter tests indicated that the peak heat release rate, total heat release and total smoke production of PP/CMSs@LDHs@CLS composites exhibited declines of 28.8 %, 29.2 % and 11.5 %, respectively, compared with those of PP/CMSs@LDHs composites. These advancements were attributed to the better dispersibility of CMSs@LDHs@CLS in PP matrix and illustrated that CMSs@LDHs@CLS observably reduced fire hazards of PP. The flame retardant property of CMSs@LDHs@CLS might relate to condensed phase flame retardant effect of char layer and catalytic charring of copper oxides. [ABSTRACT FROM AUTHOR]

In this paper, a functionalized layered double hydroxide (LDH-LS@Ni(OH) 2) flame retardant was designed and fabricated based on a multi-modifier system consisting of lignosulfonate (LS) and Ni(OH) 2 and used as a novel flame retardant for polypropylene (PP). In this multi-modifier system, LS as a compatibilizer and charring agent to improve compatibility and char yield, and Ni(OH) 2 was utilized to improve the graphitization of char residual, resulting in a PP/LDH-LS@Ni(OH) 2 composite with higher thermal stability. With the addition of LDH-LS@Ni(OH) 2 was only 15 wt%, the PP/LDH-LS@Ni(OH) 2 composite achieved a limiting oxygen index (LOI) of 30.8% and passed the UL-94 V-0 rating. At the same time, the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) were significantly reduced by 62.7%, 29.5%, and 46.2%, respectively. The flame retardant properties of LDH-LS@Ni(OH) 2 were mainly due to the catalytic charring effect of the transition metal elements and the physical barrier effect of the hydrotalcite. More specifically, as a highly efficient flame retardant, LDH-LS@Ni(OH) 2 has promising potential in reducing the fire hazards of PP composites. [Display omitted] • The dual modified LDH flame retardant was synthesized by co-precipitation method. • A novel hybrid flame retardant of S/Ni-containing (LDH-LS@Ni(OH) 2) was prepared. • PP/LDH-LS@Ni(OH) 2 (15 wt%) increased the LOI to 30.8% and passed the UL-94 V-0 rating. [ABSTRACT FROM AUTHOR]

To overcome the flammable defects of polypropylene (PP) and expand its application in more fields, it is imperative to develop PP composites with fire retardance, smoke suppression, and mechanical strength. Here, inspired by the structure of the dandelion flowers, a core-shell CMSs@LDHs flame retardant was prepared by growing LDHs nanoflakes on the surface of CMSs to combine the excellent flame retardancy of CMSs with the advanced smoke suppression of LDHs, and then it was applied into PP matrix through melt blending to satisfy the fire safety requirements of PP. With the addition of 20 wt% CMSs@LDHs, the PP/CMSs@LDHs composite passed the vertical combustion tests (UL-94) V-0 rating, and its limiting oxygen index (LOI) value of it also reached 28.9 %. The peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of the PP/CMSs@LDHs were also decreased by 46.5 %, 30.8 %, and 11.9 %, respectively, compared with those of the Neat PP. [Display omitted] • The synthetic raw materials of CMSs are renewable. • The core-shell structure was synthesized based on the flower structure of dandelion. • CMSs act as the carrier of LDHs and promote the dispersion of LDHs. • LOI of PP/CMSs@LDHs (20 wt%) reached 28.9 % and samples can pass the UL-94 V-0 rating. [ABSTRACT FROM AUTHOR]

In this paper, an interlayered/surface-modified flame retardant (LDHs@PA-MEL) was prepared via a one-pot method with phytic acid (PA), melamine (MEL), and layered double hydroxides (LDHs-C) and used as a novel flame retardant for polypropylene (PP). In LDHs@PA-MEL, PA and MEL self-assembled to form a PA-MEL supramolecular network for functionalization on the surface of LDHs-C, and phytate anions intercalated into the interlayer. The extreme dispersibility of LDHs@PA-MEL in PP is attributed to the dual modification of PA and MEL. With the addition of 20 wt%, the PP/LDHs@PA-MEL composites achieved the limiting oxygen index (LOI) of 29.6%, whereas the PP/LDHs-C composites exhibited only LOI of 24.8%. The peak heat release rate (PHRR), total heat release (THR) and total smoke production (TSP) for PP/LDHs@PA-MEL were 409 kW∙m−2, 70.3 MJ∙m−2, and 7.1 m2, respectively, which presented declines of 63.5%, 26.2% and 43.7% compared with those of Neat PP. The flame retardancy of LDHs@PA-MEL was mainly due to catalytic charring, release of non-combustible gases, and physical barrier effects. More specially, this work provides a feasible method for the preparation of high-performance PP composites. [Display omitted] • The flame retardant was synthesized by interlayered/surface dual modified LDHs. • A novel and renewable flame retardant of P/N-containing (LDHs@PA-MEL) was prepared. • One-pot method provided a feasible idea for efficient preparation of modified LDHs. • PP/LDHs@PA-MEL (20 wt%) increased the LOI to 29.6% and passed the UL-94 V-0 rating. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel hierarchical CMSs@LDH@PZN nanospheres with double shells are synthesized. • CMSs@LDH@PZN has well compatible and outstanding thermostability in PP. • CMSs@LDH@PZN enhances the flame retardancy and toxic smoke suppression of PP. Developing advanced performance polypropylene (PP) composites with less smoke, eco-friendly and efficient flame retardants (FRs) has been a growing focus of research. In particular, it was significant to reduce the emissions of smoke and toxic gases generated during the burning of PP so that it meets green and safe industrial requirements. In this work, a CMSs@LDH@PZN hierarchical core–shell framework was designed and synthesized by using carbon microspheres (CMSs) and layered double hydroxides (LDHs) nanosheets connected to CMSs by electrostatic forces with polyphosphazene (PZN). The structure, composition and morphology of CMSs@LDH@PZN were characterized by SEM, TEM, FT-IR, XRD and TG, and the results were shown the triumphant preparation of the well-designed hierarchical core–shell structure CMSs@LDH@PZN. Additionally, the total smoke production, peak heat release rate and total heat release rate of PP/CMSs@LDH@PZN composites were decreased by 56.2%, 41% and 43.4%, respectively. With the addition of 20 wt% CMSs@LDH@PZN alone, the PP/CMSs@LDH@PZN composites reached a V-0 rating in the Vertical combustion tester (UL-94), and had a limiting oxygen index (LOI) value of 29.6%. Moreover, the heat release and toxic smoke emission were significantly lessened, which can be own to the adsorption of core–shell hybrid materials and the barrier effect of the P and N element crosslinked carbon layer. Herein, this work extends the idea of preparing multipurpose high-performance composites and designs and synthesizes an eco-friendly and efficient flame retardant with a double shell structure. [ABSTRACT FROM AUTHOR]

A novel and bio-based adenosine triphosphate (ATP) pillared Mg Al layered double hydroxide (LDHs-ATP) was fabricated via calcination-reconstruction, followed by the incorporation of a highly efficient flame retardant into polypropylene (PP). The XRD result indicated that the interlayer channel of LDHs-ATP was increased to 16.6 Å. Indeed, the increase of the LDHs-ATP interlayer spacing promoted the uniform dispersion and thermal stability, which were further proved by the SEM and TG-DTG results. As expected, the PP/LDHs-ATP composite reached a LOI value of 29.1% and created a UL-94 V-0 rating with only 20 wt% LDHs-ATP loading. Furthermore, CCT illustrated that the peak heat release rate (PHRR), total heat release (THR) and total smoke release (TSR) of PP/LDHs-ATP composite exhibited a series of decreases of 55.9%, 39.5% and 56.4%, respectively, compared with that of Neat PP. [Display omitted] • A bio-based ATP pillared hydrotalcite (LDHs-ATP) was successfully fabricated. • With 20 wt% LDHs-ATP, the PP/LDHs-ATP reached LOI of 29.1% and got UL-94 V 0 rating. • The improvements attributed to synergistic effect from LDHs and ATP. [ABSTRACT FROM AUTHOR]

A novel fire retardant containing nitrogen and sulfur anion (triazine-sulphonate) was synthesized and then was directly intercalated into the interlayer of Mg/Al hydrotalcite (LDHs) by calcination-reconstruction manner to obtain nitrogen- and sulfur- containing flame retardant (LDH-NS) for polypropylene (PP) matrix. The microstructure and combustion properties of LDH-NS and its hybrid with PP composite (PP/LDH-NS) have been comprehensively characterized. XRD and SEM/EDS indicated that LDH-NS exhibited better dispersion than CO 3 2– intercalated LDHs (LDH-C) in the PP matrix. TGA showed that the thermal stability of PP/LDH-NS composites was enhanced. Cone calorimetry tests (CCT) illustrated that the peak heat release rate (PHRR), total heat release (THR) and total smoke release (TSR) of PP/LDH-NS composites were 255.8 kW m−2, 61.3 MJ m−2 and 205.7 m2 m−2, respectively, which exhibited declines of 69.7%, 43.1% and 75.0% compared with those of Neat PP. Furthermore, the PP/LDH-NS composites presented a limiting oxygen index (LOI) value of 28.6% and exhibited a vertical burning test (UL-94) V-1 rating at 30 wt% loading LDH-NS. All of these revealed that triazine sulfonate-modified LDHs significantly improved the fire performance of the PP matrix by increasing the char formation of PP/LDH-NS composites. Moreover, by adding the LDH-NS as filler for the PP matrix could promote the mechanical properties of PP/LDH-NS composites. The 30 wt% LDH-NS shown a significant fire retardance and thermal stability of PP matrix. Unlabelled Image • A fire retardant containing N and S anion (triazine-sulphonate) was synthesized. • Triazine-sulphonate pillared layered double hydroxides (LDH-NS) was prepared. • The 30 wt% LDH-NS shown a significant fire retardance and thermal stability of PP. • Triazine-sulphonate significantly promoted the flame retardancy of hydrotalcite to PP. [ABSTRACT FROM AUTHOR]

• An efficient and bio-based alginate pillared layered double hydroxides (SA@LDHs) was successfully prepared. • LOI value of PP/30 % SA@LDHs reached 30.9 % and samples can pass UL-94 V-0 rating. • Synergistic flame-retarding effect of alginate and layered double hydroxides was found. An efficient and bio-based alginate pillared hydrotalcite (SA@LDHs) was fabricated via calcination-reconstruction manner with sodium alginate (SA) and hydrotalcite (LDHs-C), and used as novel flame retardant for polypropylene (PP). The morphologies and combustion properties of SA@LDHs and its hybrid with PP composites (PP/SA@LDHs) had been characterized by SEM, TGA, cone calorimetry, LOI and UL-94 measurements. With 30 wt% loading, the SA@LDHs achieved a LOI value of 30.9 % and a UL-94 V-0 rating, whereas the LDHs-C exhibited only LOI value of 27.6 % and a UL-94 V-1 rating. The peak heat release rate, total heat release and total smoke production of PP/SA@LDHs were 260.8 kW m−2, 61.3 MJ m−2 and 8.2 m2, respectively, which presented declines of 69.2 %, 42.8 % and 32.2 % compared with those of Neat PP. These improvements could be attributed to the presence of the radical-trapping effect of SA, which leading to promote PP chains to participate in the carbonization process. [ABSTRACT FROM AUTHOR]