First Place
Brian Landi, Rochester Institute of Technology
Who Lives in Your Nanotubes
Armin Vahid Mohammadi, Auburn University
MXene Turtle Under The Sea
Simge Uzun, Drexel University
MXene Coral
Second Place
Hakan Ceylan, Max Planck Institute for Intelligent Systems
Monster Microrobots
Yiheng Chen, The Haverford School
Monarch Butterfly’s Wing
Ana Rovisco, CEMOP UNINOVA
ZTO Nanostructures
Babak Anasori, Drexel University
Synthesis of 2D Metal Carbides and Nitrides (MXenes) and Their Applications
Written by Tianyu Liu
MXenes are a large family of two-dimensional transition metal carbides and nitrides. Since the synthesis of the first MXene, Ti3C2, in Drexel University, MXenes have been utilized in a diverse array of applications: electronics, optics, energy storage devices, and catalysts, for example. Babak Anasori from Drexel University overviewed MXenes from the angles of the history, synthesis strategies, processing methods, and new applications demonstrated in 2018. In addition, Anasori revealed that most MXenes, when dispersed in water, were spontaneously oxidized by dissolved oxygen gas. The oxidation decreases the dispersion stability and the electrical conductivity of MXenes. Effective methods to slowdown MXene oxidation include storing MXenes at temperatures below room temperature, enlarging the flake size of MXenes, and processing MXenes into dry films as well as dispersing MXenes in organic solvents. Anasori also discussed unresolved challenges pertaining to MXenes, including measuring the inter-flake electrical conductivity, synthesizing MXenes with functionality-free surfaces, and preparing MXene thin films with chemical or physical vapor deposition techniques.
1st Place — Parc, a Xerox Company
Team: Eugene Beh, Michael Benedict, Elif Karatay, Jessy Rivest
Contact: [email protected]
Innovation: Redox-Assisted Dehumidification Air Conditioning
2nd Place — Magnomer
Ravish Majithia, Vishal Salian, Kumaril Kapadia
Contact: [email protected]
Innovation:Magnetizable Coatings for Recyclable Plastic Packaging
3rd Place — Membrion, Inc.
Team: Greg Newbloom
Contact: [email protected]
Innovation: Ultra-Low-Cost Ceramic Nanoporous Membranes with Tunable Porosity
Chemical Angel Network $10,000 Investment Winner — Membrion, Inc.
Team: Greg Newbloom
Contact: [email protected]
Innovation: Ultra-Low-Cost Ceramic Nanoporous Membranes with Tunable Porosity
Placidus Amama, Kansas State University
Industrial Waste Gas mixture as a feedstock in Efficient Carbon Nanotube Growth—Using an Autonomous Research System to Probe Growth Kinetics and Mechanisms
Written by Daniel Gregory
Aligned carbon nanotubes in “carpet” or “forest” arrays are highly desired in a range of applications, but require controlled properties and efficient production at large scale with low cost to meet this demand. Placidus Amama first explained the complexities of the Fischer-Tropsch synthesis method for liquid fuels, highlighting the inability to have 100% liquid fuel selectivity. From this, he described his group’s approach to the problem, wherein the gas phase of the synthesis could be combined with chemical vapor deposition to produce carbon nanotubes, alongside the liquid hydrocarbons. After showing favorable comparisons against other leading synthetic methods including carpet density, growth lifetime, and yield, Amama explained the group’s use of an autonomous research system (ARES) to optimize selected parameters. The system uses laser light to both heat the samples for chemical vapor deposition, and characterize them using Raman spectroscopy. A detailed description of the effect of heat and water content on yield was presented alongside microscopy characterizations of the optimized reaction conditions. Amama then briefly described the proposed mechanism for this reaction based on the collected data and some results from experiments changing the composition of the gas feedstock before concluding with future plans to use the ARES to further probe these compositional changes.
Michael Hausmann, EMPA and Swiss Federal Institute of Technology of Zürich
Rheology and Direct Ink Writing of Strong Cellulose Reinforced Composites
Written by Hortense Le Ferrand
Reinforcing polymeric matrices with nanoparticles is a common way to increase their mechanical properties. With the booming of the three-dimensional (3D) printing industry, there is a demand for printing parts that not only possess the benefits of 3D printing but that also perform mechanically well. Indeed, the polymers that are widely used in current printers are still weak and cannot be used in structural applications.
Cellulose nanocrystals (CNCs) are elongated nanoparticles issued from plant-based parts. CNCs align under shear to anisotropically reinforce matrices. In a direct-ink writing printing process, a viscous fluid is extruded through a nozzle and deposited on a substrate. The fluid therefore undergoes shear at the nozzle.
To develop cellulose-reinforced composites with specific mechanical properties, it is important to understand the response of CNCs under shear. For this purpose, Michael Hausmann and his colleagues performed in situ polarized rheology to directly track their dynamic orientation under shear at various concentrations. When the CNCs align, they behave like liquid crystals and display colors that are visible between cross polarizers. For example with 20 wt% of CNCs, no color is visible at low shear and the CNCs are randomly oriented, but above 200 Pa of shear stress, colors appear revealing the CNCs’ alignment. This phenomenon is observed for lower concentrations. However, above 25 wt%, the CNCs were never found to align, probably due to steric hindrance and collisions.
Since the shear profile at the tip of the nozzle of a 3D printer is well known, it is now possible to determine the conditions to realize local orientation of the CNCs in a printed part.
Xinliang Feng, Technische Universität, Dresden
Exploring New Matters with Soft and Hard Features
Written by Sean Langan
The EU-40 Materials Prize is given by the European Materials Research Society for researchers showing exceptional promise as leaders in materials science for their research done while in Europe, and this year was no exception. This Prize presentation given by Xinliang Feng of the Technische Universität on Thursday evening at the MRS Fall Meeting in Boston is a combined effort by MRS and E-MRS, and celebrates mid-career research.
Feng started with a discussion of various types of matter, hard matter and soft matter, and their various properties. Hard matter is characterized as rigid and crystalline, and often electrically conductive. Soft matter often consists of macromolecular assemblies, can be more amorphous, and is less rigid. He also described materials that were “in-between,” like carbon nanotubes, graphene, and organic and polymer crystals. Feng then transitioned into talking about his research into one of these materials that combines the properties of hard and soft matter, organic two-dimensional (2D) materials.
He described, first, 2D supramolecular molecular crystals, and then 2D polymers. Two-dimensional polymers are highly ordered, and single-monomer-thick. A porous graphene was shown as an example. Its monomers were made of rings of benzene, that when combined make a structure that is like graphene, but with large “holes” in it.
After this, a number of graphene nanoribbon structures were discussed. By varying the thicknesses of the nanoribbon, the bandgap can be controlled and thus its electrical properties. These nanoribbons shapes can be altered, from straight to curvy. Furthermore, other atoms can be added to rings within the structure to dope the material.
Feng then examined how to use interface chemistry to make these materials and move them onto other substrates. His group uses a number of techniques within interface chemistry, such as liquid/liquid interfaces, gas/solid interfaces, gas/liquid interfaces, and the Langmuir-Blodgett method. The nature of these interfaces allow for lower temperature reactions, changing the surface roughness of the material, and controlling the materials molecular orientation.
This led to a discussion on 2D supramolecular polymers with metal-dithiolene links. These were created with the Langmuir-Blodgett method, allowing for good control of thickness and the ability to create large sheets of the material that could then be transferred to another desired substrate. The material had desirable mechanical strength, electrical conductivity, and crystallinity. It was also found that in water they can lead to a hydrogen evolution reaction.
Two-dimensional polymers can also be used to make supercapacitors on the microscale, as is the case with PiCBA, a semiconducting 2D polymer. Similar materials can also be magnetic semiconducting through metal-organic frameworks, as happens when PSC monomers are turned into PTC monomers by hydrolyzing the sulfur, and then after coordinating with iron to make the sheets of the material. These networks have good electrical conductivity, are semiconducting, and at low temperatures can go from paramagnetic to ferromagnetic.
The next topic was polyimine-based 2D polymers. Depending on the interface they are created with, the thickness can be varied. These polymers were shown to absorb more light than graphene. When mechanical properties were tested, it was shown that it had a higher Young’s modulus than steel, and could be used for membrane applications.
Feng’s group is also making 2D organic crystals, which has proven quite difficult. Both polyamides and polyimides were made in this fashion, and single crystals were able to be formed.
Concluding his lecture, Feng emphasized the diverse nature of his work pursuing new materials. These materials can be made through many kinds of processes, and have unique properties and shapes.
Firstly I thank the organizer very much for the valuable blogger position given to me! This is my first time as a blogger, and twitter as well. I have also made a friend! I also enjoy the 2018 Fall MRS and Boston!
Doped perovskites have been another trend in the development of perovskites. With doping, energy band can be well altered. Swati Mamgain has done great work on this aspect! Wrote on 11/30/2018.
I am attending mainly symposium ET05 (Fundamental Aspects of Halide Perovskites (Opto)electronic and Beyond) these days during the Meeting. With regard to perovskites, obviously, the symposium ET04 (Perovskite Solar Cell--Challenge And Opportunities) is a nice complementary. Wrote on 11/30/2018
The 2018 Fall MRS Meeting is coming to an end. This Meeting has proved to be an unforgettable experience to me. Write on 11/30/2018.