Synthesis and Application of Low-cost Layered Double Hydroxides Intercalated by Gluconic Acid Anion for Flame Retardancy and Tensile Strength Conservation of High Filling Epoxy Resin

The research on supercapacitors has been attractive due to their large power density, fast charge/discharge speed and long lifespan. The electrode materials for supercapacitors are thus intensively investigated to improve the electrochemical performances. Various transition metal layered double hydroxides (LDHs) with a hydrotalcite-like structure have been developed to be promising electrode materials. Earth-abundant metal hydroxides are very suitable electrode materials due to the low cost and high specific capacity. This is a review paper on NiMn LDHs for supercapacitor application. We focus particularly on the recent published papers using NiMn LDHs as electrode materials for supercapacitors. The preparation methods for NiMn LDHs are introduced first. Then, the structural design and chemical modification of NiMn LDH materials, as well as the composites and films derived from NiMn LDHs are discussed. These approaches are proven to be effective to enhance the performance of supercapacitor. Finally, the reports related to NiMn LDH-based asymmetric supercapacitors are summarized. A brief discussion of the future development of NiMn LDHs is also provided.

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Improving the flame retardancy of ethylene vinyl acetate composites by incorporating layered double hydroxides based on Bayer red mud

e-Polymers ◽

10.1515/epoly-2019-0015 ◽

2019 ◽

Vol 19 (1) ◽

pp. 129-140 ◽

Cited By ~ 2

Author(s):

Yi Qian ◽

Kangjia Jiang ◽

Long Li

Keyword(s):

Vinyl Acetate ◽

Flame Retardancy ◽

Layered Double Hydroxides ◽

Red Mud ◽

Ethylene Vinyl Acetate ◽

Precipitation Method ◽

Infrared Spectrometry ◽

Cone Calorimeter Test ◽

Bayer Red Mud ◽

Double Hydroxides

AbstractNowadays, reducing the hazards of bayer red mud (BRM) is an important research direction in the fields of environmental and safety. In this article, Mg/Al/Fe ternary layered double hydroxides (Mg/Al/Fe-LDHs) were synthesized successfully by a co-precipitation method based on introducing Mg2+ into the BRM suspension. The thermogravimetric analysis (TGA) results showed that the decomposition rate of LDHs is higher than that of BRM, which indicates that LDHs can absorb more heat than BRM during the decomposition process. Subsequently, BRM and LDHs were added into the ethylene vinyl acetate (EVA) to investigate its effects on reducing flammability of the composites. The cone calorimeter test (CCT) results demonstrated that 50 wt% LDH-B can make the peak value of HRR (PHRR) decrease from 1694.8 kW/m2 (EVA) to 199.2 kW/m2 (ELDH2). The smoke density test (SDT) results showed that the luminous flux of ELDH2 is nearly 95% at the end of test with a pilot flame, which is much higher than that of EVA and EBRM. The thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR) results confirmed that LDHs can improve the thermal stability of composites and reduce the production of some toxic gases. Compared with BRM, the improved flame retardancy of Mg/Al/Fe-LDHs is ascribed to the introduction of Mg2+, which offering an enhanced catalytic carbonization capability, as well as the physical barrier effect of char residue layer catalyzed by the lamellar LDHs

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FDM Prototype Experimental Research of Processing Parameter Optimization to Achieve Higher Tensile Stress

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.220-221.767 ◽

2015 ◽

Vol 220-221 ◽

pp. 767-773 ◽

Cited By ~ 2

Author(s):

Ilmars Brensons ◽

Svetlana Polukoshko ◽

Andris Silins ◽

Natalija Mozga

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Epoxy Resin ◽

Fused Deposition Modeling ◽

Low Cost ◽

Rapid Prototype ◽

Layer By Layer ◽

Processing Parameter ◽

Practical Applications ◽

Fused Deposition

Fused Deposition Modeling (FDM) is one of most common ways of rapidly producing a part. Heated material (most commonly – plastic) is used to extrude it through a nozzle and deposit on a surface layer by layer until the part is fully produced. FDM has become one of the most popular in rapid production area due to its low cost, available materials and versatility.Due to fact that part is made layer by layer and each additional layer is deposited on top of a layer that is already a little below material melting point, part maintains different mechanical properties in various directions. These varying mechanical properties affect the part usability in practical applications. Critical point is tensile strength.The objective of this paper is to research optimal processing parameters for FDM prototyping to improve tensile strength. Several rapid prototype models (tensile test samples) with various geometry of longitudinal reinforcement channels were built. As reinforcing material, the epoxy resin was used, because it has higher tensile strength when solid and allows filling channels with various geometry. All made samples were tested for tensile strength. Experiment was carried out to confirm the effectiveness of this approach. From the results, it is found how different amount of epoxy resin affects part tensile strength.

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