Join us on Zoom for Veronica’s defense titled “Custom Geometry-Based Algorithms for the Classification and Quantification of Order in Anisotropic Particle Assemblies".

Dr. Ru Deng and graduate student Chengyuan Wang report on hydrogen-bonded supramolecular miktoarm star polymer containing three distinct helical arms. By installing one barbituric acid (Ba) unit at the center of a diblock helical poly(methacrylamide), it formed a miktoarm star polymer with a helical poly(isocyanide) functionalized with a Hamilton Wedge (HW) moiety in its chain-end through the assembly driven by complementary hydrogen-bonding interactions between the HW and Ba units.

Join us on Zoom for Fangyuan’s defense titled “Electric Field-Directed Assembly of Anisotropic Colloids".

Congrats to 2022 PMSE Fellow, Marcus Weck, “for pioneering and innovative contributions that interface supramolecular and polymer chemistry to access new applied polymeric and colloidal materials.”

Graduate student Eman Ahmed and post-doctoral student Tyler Womble collaborated with the Jang group at Georgia Tech to investigate the self-assembly behavior of triblock terpolymers into multicompartment micelles. Linear triblock terpolymers containing hydrophilic, lipophilic and fluorophilic domains were synthesized using ring-opening metathesis polymerization (ROMP). Our scaffold design offers an efficient approach for the synthesis of the target materials with fast polymerization kinetics, complete block incorporation and control over block sequence. Micelles with “Core–shell–corona”, “disk-like”, “raspberry-like” and “worm-like” morphologies were observed by cryogenic transmission electron microscopy and dissipative particle dynamics simulations. This work is the first report of the assembly of multicompartment micelles by linear triblock terpolymers synthesized using ROMP. Check it out here.

Graduate student Cicely Shillingford and undergraduate student Brandon present capillary assembly of liquid particles (CALP) as a microfabrication strategy to create arbitrarily shaped polymer colloids. In this method, emulsion particles are deposited into patterned microarrays within a fluidic cell, where coalescence, polymerization, and extraction then follows. Eleven geometrically diverse patchy and Janus particles are presented, including triblock ellipsoids, planar tetramer, and pentagonal patchy particles. The work contributes a method for the design and fabrication of micro/nanoparticles with more complex, multicomponent structure for the targeting of hierarchical functional materials, including use in filtration devices, sensors, diagnostics, solid-state catalysts, and optical electronics. Check it out here.

Graduate students Mingzhu Liu and Veronica Grebe synthesize DNA functionalized dipatchy particles into colloidal superstructures using cooperative depletion and DNA-mediated interactions. The assembly of various superstructures are reported, including flower‐like Kagome, brick‐wall like monolayer, orthogonal packed single or double layers, wrinkled monolayer, and colloidal honeycomb superstructures. The flower-like Kagome and brick-wall like structures are analyzed and quantified using a custom algorithm. The yielded structures can be tuned by changing the patch size of the particle, as well as the assembly conditions. The work contributes an empirical phase diagram, contributes domain knowledge to the design of 2D materials of various superstructures, and is potentially translatable to 3D. Check out the article here.

Graduate students Veronica Grebe and Mingzhu Liu developed algorithms capable of image analysis for classifying colloidal structures based on abstracted interparticle relationship information and quantitatively analyzing the abundance of each structure in mixed pattern assemblies. One-dimensional and two-dimensional polymorphic crystals are analyzed using the algorithms, and the percent abundance of each particle class is defined. The work is open-source, able to be built upon, and is expected to have use in quantitative analysis of images comprised of ellipsoidal materials, including nanoparticles and biological matter. Check it out here.

Graduate students Mingzhu Liu, Fangyuan Dong and Nicolle Jackson describe a synthetic strategy for the fabrication of multicomponent colloidal “molecules” with controllable complex morphologies and compositionally distinct lobes, enabling a scalable bulk synthesis of customized chiral colloidal particles with geometric and compositional chirality by a sequential seeded growth method. The synthetic protocol presents a versatile platform for constructing colloidal molecules with multiple components having customized shapes and functionalities, with the potential to impact the design of chromatic patchy particles, colloidal swimmers, and chiral optical materials, as well as informing programmable assembly. Read the article here.

Molecular Design Institute graduate students Fangyuan Dong, Mingzhu Liu and Veronica Grebe reported in Chemistry of Materials nineteen uniquely shaped anisotropic colloids that form ordered crystals under dielectrophoretic fields. The various particle shapes resulted in crystalline phases with p6m, cmm or p2 plane group symmetries, two plastic phases, and a disordered phase. The observations establish a relationship between particle shape and the resulting 2D structures, providing guidance for the design of 2D colloidal crystals. Link to the article here.

Graduate students Mingzhu Liu and Veronica Grebe use regioselective depletion interactions to introduce directional bonding and direct the assemble anisotropic biphasic colloids. By changing the depletion conditions, the assembly of a binary colloidal mixture can be tuned. Combining these materials as triblock biphasic colloids yields particles of various aspect ratios that can similarly be tuned by depletion conditions. The particle assemble into various colloidal superlattices and superstructures with optimized center-to-center or pole-to-pole interactions, dependent on the aspect ratio. Polymorphic crystallization is observed and quantified using algorithms developed. The work contributes selective control of regional attractive interactions, precluding the need for surface treatment and functionalization. Check out the article here.

Graduate students Michael Kuepfert and Peiyuan (Tony) Qu have a new article published in Chemistry Europe:

Photoresponsive molecular systems enable the external modulation of chemical functions to develop smart devices and materials. Introducing molecular light triggers can provide spatial and temporal control over chemical reactions, which can facilitate the regulation of biological processes and the performance of materials. Here, we introduce a photoswitchable moiety (i.e. spiropyran) onto amphiphilic polymeric nanoreactors that change their catalytic activity in response to light irradiation. The self-assembled nanoreactors alter their morphologies in response to UV-light which in turn manipulates substrate accessibility to the catalytic site.

Check out the article here.

Graduate students Cicely Shillingford and Veronica Grebe use templated capillary assembly to study the fabrication of square-packed lattices of spherical colloids on patterned templates. Conditions were found to maximize square-packed domains. Particle tracking methods are employed to monitor the assembly process and the conversion between square and hexagonal packing. A cyclical transition between 4 and 6 coordinated particles was found throughout the meniscus recession. The work is scalable and expands domain knowledge of the defect-free assembly of nonclose-packed lattices. Check it out here.