scholarly journals A Study of the Key Factors on Production of Graphene Materials from Fe-Lignin Nanocomposites through a Molecular Cracking and Welding (MCW) Method

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 154
Author(s):  
Qiangu Yan ◽  
Timothy Ketelboeter ◽  
Zhiyong Cai

In this work, few-layer graphene materials were produced from Fe-lignin nanocomposites through a molecular cracking and welding (MCW) method. MCW process is a low-cost, scalable technique to fabricate few-layer graphene materials. It involves preparing metal (M)-lignin nanocomposites from kraft lignin and a transition metal catalyst, pretreating the M-lignin composites, and forming of the graphene-encapsulated metal structures by catalytic graphitization the M-lignin composites. Then, these graphene-encapsulated metal structures are opened by the molecule cracking reagents. The graphene shells are peeled off the metal core and simultaneously welded and reconstructed to graphene materials under a selected welding reagent. The critical parameters, including heating temperature, heating time, and particle sizes of the Fe-lignin composites, have been explored to understand the graphene formation mechanism and to obtain the optimized process parameters to improve the yield and selectivity of graphene materials.

2013 ◽  
Vol 788 ◽  
pp. 57-60
Author(s):  
Chun Cao ◽  
Chun Dong Zhu ◽  
Chen Fu

Warm pressing forming technology has been gradually applied to the forming of automotive friction materials. How to ensure product performance to achieve the target at the same time achieve the maximum energy saving is the research focus of this study. In this paper, by using finite element method, the field of automotive friction materials in warm pressing forming was analyzed, reveals the relationship between the temperature field and the heating temperature/heating time. Furthermore, the energy consumption was analyzed and compared it with hot pressing forming process. The results will have significant guiding to the process optimization in warm pressing forming.


2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Peng Bing ◽  
Wang Jia ◽  
Chai Li-yuan ◽  
Wang Yun-yan ◽  
Mao Ai-li

The photocatalytic degradation rates of methyl orange and antibacterial properties of nano-Ag/TiO2 thin film on ceramics were investigated in this study. XRD was used to detect the structure of film to clarify the impacts on the rates and properties. The effect of film layers, heating temperature, heating time, and embedding of Ag+ on the degradation rates and antibacterial properties were ascertained. The nano-Ag/TiO2 film of 3 layers with AgNO3 3% embedded and treated at 350°C for 2 h would exhibit good performance.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4032
Author(s):  
Lianlian Liu ◽  
Niclas Solin ◽  
Olle Inganäs

Humic acid (HA) is a biopolymer formed from degraded plants, making it a ubiquitous, renewable, sustainable, and low cost source of biocarbon materials. HA contains abundant functional groups, such as carboxyl-, phenolic/alcoholic hydroxyl-, ketone-, and quinone/hydroquinone (Q/QH2)-groups. The presence of Q/QH2 groups makes HA redox active and, accordingly, HA is a candidate material for energy storage. However, as HA is an electronic insulator, it is essential to combine it with conductive materials in order to enable fabrication of HA electrodes. One of the lowest cost types of conductive materials that can be considered is carbon-based conductors such as graphite. Herein, we develop a facile method allowing the biocarbon to meet carbon; HA (in the form of a sodium salt) is mixed with graphite by a solvent-free mechanochemical method involving ball milling. Few-layer graphene sheets are formed and the HA/graphite mixtures can be used to fabricate HA/graphite hybrid material electrodes. These electrodes exhibit a conductivity of up to 160 S·m−1 and a discharge capacity as large as 20 mAhg−1. Our study demonstrates a novel methodology enabling scalable fabrication of low cost and sustainable organic electrodes for application as supercapacitors.


2022 ◽  
Vol 6 (1) ◽  
Author(s):  
Tian Carey ◽  
Abdelnour Alhourani ◽  
Ruiyuan Tian ◽  
Shayan Seyedin ◽  
Adrees Arbab ◽  
...  

AbstractThe scalable production of two-dimensional (2D) materials is needed to accelerate their adoption to industry. In this work, we present a low-cost in-line and enclosed process of exfoliation based on high-shear mixing to create aqueous dispersions of few-layer graphene, on a large scale with a Yw ~ 100% yield by weight and throughput of ϕ ~ 8.3 g h−1. The in-line process minimises basal plane defects compared to traditional beaker-based shear mixing which we attribute to a reduced Reynolds number, Re ~ 105. We demonstrate highly conductive graphene material with conductivities as high as σ ∼ 1.5 × 104 S m−1 leading to sheet-resistances as low as Rs ∼ 2.6 Ω □−1 (t ∼ 25 μm). The process is ideal for formulating non-toxic, biocompatible and highly concentrated (c ∼ 100 mg ml−1) inks. We utilise the graphene inks for inkjet printable conductive interconnects and lithium-ion battery anode composites that demonstrate a low-rate lithium storage capability of 370 mAh g−1, close to the theoretical capacity of graphite. Finally, we demonstrate the biocompatibility of the graphene inks with human colon cells and human umbilical vein endothelial cells at high c ∼ 1 mg ml−1 facilitating a route for the use of the graphene inks in applications that require biocompatibility at high c such as electronic textiles.


2019 ◽  
Author(s):  
Noelia Losada-Garcia ◽  
Angel Berenguer-Murcia ◽  
Diego Cazorla-Amorós ◽  
Jose M Palomo

<p>A new simple, rapid, and efficient methodology to produce undamaged graphene sheets from graphite flakes in water by a bio-exfoliation technology is described. The methodology consists in the application of a lipase, with a very exclusive mechanism of interaction with hydrophobic surfaces, combined with a previous mechanical sonication, to selectively generate biographene in water. The adsorption of the lipase on the graphene sheets permits to keep the sheets separated in comparison with other methods. It is possible to obtain more than 80% of graphene (in the form of Few Layer Graphene) from low-cost graphite and with less damage compared to commercial graphene oxide (GO) or reduced GO. Experimental analysis demonstrated the formation of bilayer graphene mainly using lipase from Thermomyces lanuginosus (TLL).</p>


Author(s):  
Jiazhong Xu ◽  
Tianyu Fu ◽  
Zhao Hui

The glass fiber reinforced polypropylene (GF/PP) composite ring specimens were fabricated based on the composites prepreg tape winding process. The heated winding process was simulated by ANSYS software to obtain the temperature distribution of the wound layer of the specimen. At the same time, the temperature of the wound layer was collected and stored using a temperature-controlled recorder. The temperature fields between the wound layers were found to be different significantly, and the temperature measured through experiments was generally below the simulation results, where it is especially noticeable in the fusion zone. After the recrystallization of GF/PP specimen, the maximum shear strength that the specimen can withstand was improved. The response surface method was used to test and analyze the influence of recrystallization on the mechanical properties of the specimen, Obtain optimized process parameters, heating temperature of 91 °C, pressure of the press roller is 106 N, heating time of 13 min, the highest sample obtained is 28.67Mpa. The experimental results show that the influence of recrystallization parameters on the mechanical properties of the composite specimens (from large to small) are: heating temperature, heating time, and the roller pressure.


Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 377 ◽  
Author(s):  
Gabriela Tubon Usca ◽  
Cristian Vacacela Gomez ◽  
Marco Guevara ◽  
Talia Tene ◽  
Jorge Hernandez ◽  
...  

A novel method is presented to prepare few-layer graphene (FLG) in N-methyl-2-pyrrolidinone (NMP) by using a simple, low-cost and energy-effective shear exfoliation assisted by zeolite and using a cappuccino mixer to produce shear. We propose that the exfoliation of natural graphite flakes can be achieved using inelastic collisions between graphite flakes and zeolite particles in a dynamic colloidal fluid. To confirm the exfoliation of FLG, spectroscopy and morphological studies are carried out using Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, the obtained graphene shows a linear flow of current and low resistance. The proposed method shows great promise for the industrial-scale synthesis of high-quality graphene with potential applications in future graphene-based devices, and furthermore, this method can be extended to exfoliate inorganic layered materials such as BN and MoS2.


Nano Hybrids ◽  
2016 ◽  
Vol 10 ◽  
pp. 1-13
Author(s):  
M.S. Shamsudin ◽  
S.J. Fishlock ◽  
M. Rusop ◽  
S.M. Sanip ◽  
Suan Hui Pu

Graphene has attracted wide interest across a range of applications due to its electrical, mechanical and optical properties. The use of a low-cost, table-top chemical vapour deposition system to deposit few-layer graphene onto copper is reported in this work. Characterisation of the graphene is performed using Raman spectroscopy and atomic force microscopy. The results show that few-layer graphene can be deposited at 1000 °C using CH4 as a carbon precursor, and 5% H2, 95% N2 forming gas as a diluent. The effects of deposition temperature, deposition time, and forming gas addition on graphene film quality was studied experimentally. An increase in graphene quality was observed when forming gas was added during deposition.


RSC Advances ◽  
2016 ◽  
Vol 6 (21) ◽  
pp. 17158-17162 ◽  
Author(s):  
Bipinchandra K. Salunke ◽  
Beom Soo Kim

A new, facile, low cost, environmentally safe process is demonstrated for the production of few layer graphene by liquid phase exfoliation of graphite using extracts of medicinal plants in water.


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