scholarly journals Hydrothermal Synthesis of Lanthanum-Doped MgAl-Layered Double Hydroxide/Graphene Oxide Hybrid and Its Application as Flame Retardant for Thermoplastic Polyurethane

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Qian ◽  
Peng Qiao ◽  
Long Li ◽  
Haoyue Han ◽  
Haiming Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Layered Double Hydroxide ◽  
Flame Retardancy ◽  
Thermoplastic Polyurethane ◽  
Smoke Suppression ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Cone Calorimeter Test ◽  
Double Hydroxide

A novel lanthanum-doped MgAl-layered double hydroxide/graphene oxide hybrid (La LDH/GO) with a La3+/Al3+ molar ratio of 0.05 was successfully synthesized by the hydrothermal method. The structure and morphology of as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). Then, La LDH/GO was added into thermoplastic polyurethane (TPU) to investigate its effect on flame retardancy, smoke suppression, and thermal stability of TPU composites. The cone calorimeter test (CCT) results indicated that the peak heat release rate (PHRR) and peak smoke production rate (PSPR) values of TPU with La LDH/GO decreased by 33.1% and 51% compared with neat TPU, respectively. Therefore, La LDH/GO can play a good role in flame retardancy and smoke suppression of TPU matrix during combustion. In the meantime, La LDH/GO could improve the char yield of TPU composites, which is attributed to the interaction between the physical barrier effect of GO and the catalytic effect of 0.05 La LDH.

Characterization of Layered Double Hydroxide Modified with Sodium Dodecyl Sulfate and its Dispersion in Polyethylene

2013 ◽  
Vol 591 ◽  
pp. 138-141
Author(s):  
Zhi Dong Han ◽  
Xin Ke Zhang ◽  
Yue Wang ◽  
Zheng Quan Jiang ◽  
Peng Wang
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Layered Double Hydroxide ◽  
Sodium Dodecyl ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Dodecyl Sulfate ◽  
The Matrix ◽  
Mixing Method ◽  
Double Hydroxide

Mg-Al layered double hydroxide (LDH) was modified with sodium dodecyl sulfate (SDS) by regeneration method. The structure of modified LDH (SDS-LDH) was investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The composites of SDS-LDH and polyethylene (PE) were prepared by melt blending and solution mixing method with maleated PE (PEgMA) as compatibilizer. The structure of the composites and the dispersion of SDS-LDH in the matrix were investigated by XRD and transmission electron microscopy (TEM), respectively. The results reveal that SDS was successfully intercalated into the interlayer space of LDH. SDS-LDH was hardly exfoliated in PE/PEgMA by melt blending. The nanocomposites of PE/(PEgMA/SDS-LDH) were successfully prepared by melt blending PE with SDS-LDH/PEgMA master-batch obtained by solution mixing. Homogeneous dispersion of SDS-LDH in the matrix was observed by TEM.

scholarly journals Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yun Zhao ◽  
Fenfei Xiao ◽  
Qingze Jiao
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Layered Double Hydroxide ◽  
Hydrothermal Reaction ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Double Hydroxide ◽  
Scanning Electron

Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al LDHs could be obtained when the pH value was about 10.0 with a long reaction time (12–18 h) at 180°C.

scholarly journals Removal of Lead from Aqueous Solution by Adsorption using Magnesium Aluminium Hydrogenphosphate Layered Double Hydroxides

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Zaini Hamzah ◽  
Mohd Najif Ab Rahman ◽  
Yamin Yasin ◽  
Siti Mariam Sumari ◽  
Ahmad Saat
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Layered double hydroxide with molar ratio of 4 (MAN 4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was then later going through ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP 4). The solid produced were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of lead solution by MAHP 4 was carried out using batch experiment by mixing the lead solution and the solid of layered double hydroxide. The effects of various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for lead removal was found to be at pH of 5 and the optimum time of lead removal was found at 2 hours. The isotherm data was analysed using Langmuir and the correlation coefficient of 0.998 was obtained. The maximum adsorption capacity, Qo (mg/g) of 500 mg/g was also recorded from the Langmuir isotherm. The remaining lead solution was determined by using EDXRF (Energy Dispersive X-Ray Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP 4 was an interesting adsorbent for removing lead from aqueous solution.

Layered double hydroxide-decorated flexible polyurethane foam: significantly improved toxic effluent elimination

RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97458-97466 ◽  
Author(s):  
Lei Liu ◽  
Wei Wang ◽  
Yuan Hu
Keyword(s):  
Thermal Stability ◽  
Polyurethane Foam ◽  
Layered Double Hydroxide ◽  
Flame Retardancy ◽  
Smoke Suppression ◽  
Layer By Layer ◽  
Layer Method ◽  
Flexible Polyurethane Foam ◽  
Flexible Polyurethane ◽  
Double Hydroxide

A layered double hydroxide-based fire-blocking coating was deposited on the surface of a flexible polyurethane foam using a layer-by-layer method to improve its thermal stability, flame retardancy and smoke suppression properties.

Synthesis of CoAl-layered double hydroxide/graphene oxide nanohybrid and its reinforcing effect in phenolic foams

2017 ◽  
Vol 30 (6) ◽  
pp. 688-698 ◽  
Author(s):  
Zhengzhou Wang ◽  
Xiaoyan Li
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Layered Double Hydroxide ◽  
Photoelectron Spectroscopy ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Compressive And Flexural Strengths ◽  
Double Hydroxide ◽  
Thermal Stability Of

A graphene oxide (GO) immobilized with layered double hydroxide (CoAl-LDH/GO) nanohybrid was prepared via a hydrothermal method and characterized by transmission electron microscopy, field emission scan electronic microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis (TGA). The TGA results show that the immobilization of CoAl-LDH nanoparticles on GO surface greatly promotes the thermal stability of GO. More importantly, the incorporation of the CoAl-LDH/GO nanohybrid into PF foams leads to not only a great improvement in their mechanical strengths but also a reduction in their brittleness and friability. Specifically, compared to neat phenolic (PF) foam, at only 0.9 phr (parts per hundred of resin by mass) of CoAl-LDH/GO, the compressive and flexural strengths of the modified PF foam increase by 54.8% and 35.2%, respectively, and pulverization ratio decreases by 55.2%. The addition of the CoAl-LDH/GO nanohybrid also results in an increase in the limiting oxygen index and a decrease in the peak heat release of the modified PF foam in cone calorimeter test. Moreover, the thermal stability of the PF foam is enhanced by the addition of the nanohybrid.

scholarly journals Porous Layered Double Hydroxide/TiO2 Photocatalysts for the Photocatalytic Degradation of Orange II

2020 ◽  
Vol 4 (2) ◽  
pp. 39
Author(s):  
Rodrigue Djeda ◽  
Gilles Mailhot ◽  
Vanessa Prevot
Keyword(s):  
Tio2 Nanoparticles ◽  
Layered Double Hydroxide ◽  
Colloidal Suspension ◽  
Textural Properties ◽  
Pure Tio2 ◽  
Photocatalytic Properties ◽  
Orange Ii ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Double Hydroxide

Layered Double Hydroxide (LDH)/TiO2 nanocomposites with photocatalytic properties were synthesized by both impregnation and the direct coprecipitation of LDH matrices using a colloidal suspension of TiO2 nanoparticles. While the two methods led to an efficient TiO2 nanoparticle immobilization, the direct coprecipitation allowed us to tune the amount of immobilized TiO2 within the materials. The LDH/TiO2 nanocomposites obtained were deeply characterized by chemical analysis (ICP-AES), Powder X-ray diffraction (XRD), Fourier Transformed Infra-Red (FTIR), Thermogravimetric analysis (TGA), and High-Resolution Transmission Electron Microscopy (HRTEM). Clearly, the immobilization of TiO2 by direct coprecipitation promoted a modification of the textural properties and a net increase in the surface area. The crystallized TiO2 nanoparticles can be distinctly visualized by HRTEM at the surface of the layered material. Several parameters, such as the nature of the chemical composition of LDH (ZnAl and MgAl), the method of immobilization and the amount of TiO2, were shown to play a crucial role in the physicochemical and photocatalytic properties of the nanocomposites. The photocatalytic efficiency of the different LDH/TiO2 nanocomposites was investigated using the photodegradation of a model pollutant, the Orange II (OII), and was compared to a pure TiO2 colloidal solution. The degradation tests revealed that the nanocomposite obtained from MgAl LDH at a low MgAl LDH/TiO2 ratio was the most efficient for the photodegradation of OII leading to complete mineralization in 48 h.

Intercalation of Collagen and Soybean Peptides into Zn–Al Layered Double Hydroxide

2008 ◽  
Vol 8 (1) ◽  
pp. 428-431 ◽  
Author(s):  
Sumio Aisawa ◽  
Aiko Yasutake ◽  
Satoshi Takahashi ◽  
Hidetoshi Hirahara ◽  
Eiichi Narita
Keyword(s):  
Layered Double Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Collagen Peptides ◽  
Transmission Electron ◽  
New Type ◽  
Diffraction Peaks ◽  
Xrd Patterns ◽  
Double Hydroxide

In order to develop a new type biocompatible organic/inorganic nanohybrid material, an intercalation of collagen peptides (CP) and soybean peptide (SP) into Zn–Al layered double hydroxide (LDH) by the coprecipitation reaction has been investigated. The peptide/LDH has been characterized by chemical analysis, powder X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TG) and transmission electron microscopy (TEM). According to the XRD patterns and Raman spectra, the solid products were found to contain peptide and to show broad diffraction peaks with LDH structures. The CP/LDH and SP/LDH possess the expanding LDH structure, d00l = 2–3 nm, confirming that both peptides were intercalated into the LDH interlayer space with low organized stacking arrangement.

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