Erb Randall M., Segmehl Jana, Schaffner Manuel, Studart Andre R. (2013), Temporal response of magnetically labeled platelets under dynamic magnetic fields, in SOFT MATTER
, 9(2), 498-505.
Studart André R., Libanori Rafael, Erb Randall M. (2013), Replicating biological design principles in synthetic composites, in Fratzl Dunlop Weinkamer (ed.), RSC Publishing, London, 322-358.
Erb Randall M., Sander Jonathan S., Grisch Roman, Studart André R. (2013), Self-shaping composites with programmable bioinspired microstructures, in Nature Communications
, 4, 1712.
Erb Randall M., Segmehl Jana, Charilaou Michalis, Loeffler Joerg F., Studart Andre R. (2012), Non-linear alignment dynamics in suspensions of platelets under rotating magnetic fields, in SOFT MATTER
, 8(29), 7604-7609.
Sommer Marianne R., Erb Randall M., Studart Andre R. (2012), Injectable Materials with Magnetically Controlled Anisotropic Porosity, in ACS APPLIED MATERIALS & INTERFACES
, 4(10), 5086-5091.
Erb Randall M., Cherenack Kunigunde H., Stahel Rudolf E., Libanori Rafael, Kinkeldei Thomas, Muenzenrieder Niko, Troester Gerhard, Studart Andre R. (2012), Locally Reinforced Polymer-Based Composites for Elastic Electronics, in ACS APPLIED MATERIALS & INTERFACES
, 4(6), 2860-2864.
Erb RM, Libanori R, Rothfuchs N, Studart AR (2012), Composites Reinforced in Three Dimensions by Using Low Magnetic Fields, in SCIENCE
, 335(6065), 199-204.
Due to the large strength to weight ratio of composites, their implementation as load-bearing materials is exponentially growing especially in aerospace, the automobile industry, and construction. The majority of commercial composites today are produced with aligned continuous fibers that lead to significant material strength along a single axis. To gain total in-plane strength, industrial users laminate sheets of fiber composites together in different orientations. Although this process necessarily reduces the original anisotropic composite strength, the primary weakness of commercial laminates remains the stiffness in the third, out-of-plane direction. Instead, if discontinuous reinforcing elements (e.g. fibers, platelets and rods) can be deliberately aligned within a composite, then isotropic reinforcement becomes a possibility.The goal of this research project is to exploit our recent discovery of a ultra-high response of Fe3O4-modified Al2O3 platelets under magnetic fields to construct a new class of 3-D reinforced composites. Al2O3 platelets are a leading contender for discontinuous reinforcement and can easily be modified with magnetite nanoparticles through electrostatic adsorption mechanisms. This procedure allows for the remote control of reinforcement orientation under magnetic fields that can, among numerous exciting possibilities, lead to out-of-plane platelet alignment. To achieve this goal, we will first investigate the surprising alignment effect and fast dynamics of these modified platelets in magnetic fields through methodical experimentation and model development. Next we will extend our models to other anisotropic particles frequently used as discontinuous reinforcement to prove the universality of this method. We will then incorporate modified particles into common polymer matrices and apply magnetic fields to achieve unique and interesting alignment configurations. Finally, we will measure the mechanical properties of this new class of composites and determine if contemporary theory adequately describes these systems. Since the deliberate control of reinforcement particles would help solve the primary weakness of traditional composites, a deeper understanding of and investigation into this ultra-high magnetic response in modified Al2O3 platelets is merited.