On December 14th, researchers from the Institute of Ceramics and Glass (ICV) and the Institute of Microelectronics and Nanoscience of the University of Aix-Marseille in Spain have used 3D printed graphene oxide scaffolds as the basis for lightweight hybrid structures. The structure retains many of the ideal properties of graphene, including electrical conductivity and water adsorption capacity.
Researchers infiltrated graphene oxide scaffolds with alkoxide precursor solutions to produce hybrid structures that show potential applicability, such as pollutant removal, water filtration, catalysis, drug delivery, and energy generation and storage.
Limitations of 3D printing graphene
Graphene is an allotrope of carbon and has become a common element in research related to energy production and microelectronics, as well as in the development of new technologies such as biomedicine and sensing. The lightweight properties, high electrical and thermal conductivity, and mechanical strength of the material are highly desired. Although much of the potential of graphene comes from the deployment of the material in a single layer, the use of graphene for 3D printing still faces huge challenges.
However, researchers at Virginia Tech and Lawrence Livermore National Laboratory (LLNL) are developing a high-resolution 3D printing method (involving graphene dispersed in a gel to make a 3D printable resin) After that, further measures were taken to exploit the potential of graphene. LLNL also collaborated with a team from the University of California, Santa Cruz, to study the 3D printing technology for graphene-based aerogel electrodes in energy storage devices.
Graphene is also used to create 3D printed self-inducing armor and modernize transportation networks. Elsewhere, new research reveals how the structure of water changes when it comes in contact with the graphene surface.
Recently, researchers from the Additive Manufacturing Center of the University of Nottingham have made a breakthrough in the use of graphene-based electronic devices for 3D printing, and developed an inkjet-based 3D printing technology that can pave the way for replacing single-layer graphene as a contact material. the way. 2D metal semiconductor.
Create graphene oxide-silica structure
Graphene oxide is considered to be a viable building block for producing 3D connected lightweight structures with high porosity, conductivity, flexibility and large surface area. Scientists aim to solve some of the shortcomings of graphene oxide, such as its mechanical weakness and its vulnerability to flame damage, by anchoring other materials to the 3D graphene structure to form hybrid materials or composite materials.
First, the researchers used water-based ink prepared from graphene oxide nanosheets, 3-D Inks LLC’s three-axis robotic automatic casting system and RoboCAD software to 3D print the 3D printed graphene oxide scaffold. The stent was printed with a needle with a diameter of 410 μm into a rectangular parallelepiped composed of 16 layers of evenly distributed rods, which were placed at right angles to the adjacent layers.
The structure is then frozen in liquid nitrogen for 10 seconds, then it is freeze-dried (freeze-dried) and processed in a graphite furnace at 1200 degrees Celsius to enhance the reduction of graphene oxide, thereby freezing it. At this time, the size of the 3D printed graphene oxide structure is 12x12x5mm.
The next step involves permeating the graphene oxide scaffold through what the researchers call a sol-gel pathway, which involves the cross-linking of low-temperature gel with ammonia vapor.
Two solutions containing tetraethyl orthosilicate, ethanol, deionized water and hydrochloric acid were prepared, which were called SiO2 sol (silica) and SiAl sol (silica-alumina), respectively. The graphene oxide holder was half-dipped in each sol in an airtight container for five minutes, and then placed on a stationary platform just above the liquid surface. The sample was placed at room temperature for 24 hours to cause prolonged condensation and stiffness of the impregnated structure through ammonia catalysis. Then, the stent was washed with ethanol to remove any vapor residues.
Compare scanning electron microscope (SEM) images of different materials. (A) Original graphene oxide scaffold, (b-e) graphene oxide-silica structure. The picture comes from the “Journal of the European Ceramic Society”. Results and potential applications Researchers have found that, compared with untreated graphene oxide scaffolds, the 3D printed graphene oxide-silica structure maintains a high degree of porosity, while its compressive strength is increased by 250-800%. The hybrid structure also maintains “significant conductivity”, but the main enhancement is reflected in the hydrophilicity of the structure. It is observed that the superfine silica-based covering of the scaffold has an important influence on the wetting characteristics of the structure. Compared with the untreated graphene oxide scaffold, the structure becomes completely hydrophilic, and its water absorption capacity is increased ten times. The enhanced properties of the graphene oxide-silica structure indicate that they can be suitable for use as absorbents, pollutant removal, gas sensing, heat storage, or use in photocatalytic water splitting applications.
Link to this article： 3D printing graphene oxide method is coming
Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting:https://www.cncmachiningptj.com/，thanks！