Production of objects with varied mechanical properties is challenging for current manufacturing methods. Additive manufacturing could make these multimaterial objects possible, but methods able to achieve multimaterial control along all three axes of printing are limited. Here we report a multi-wavelength method of vat photopolymerization that provides chemoselective wavelength-control over material composition utilizing multimaterial actinic spatial control (MASC) during additive manufacturing. The multicomponent photoresins include acrylate- and epoxide-based monomers with corresponding radical and cationic initiators. Under long wavelength (visible) irradiation, preferential curing of acrylate components is observed. Under short wavelength (UV) irradiation, a combination of acrylate and epoxide components are incorporated. This enables production of multimaterial parts containing stiff epoxide networks contrasted against soft hydrogels and organogels. Variation in MASC formulation drastically changes the mechanical properties of printed samples. Samples printed using different MASC formulations have spatially-controlled chemical heterogeneity, mechanical anisotropy, and spatially-controlled swelling that facilitates 4D printing.
Congrats to Johanna for having her paper on MASC 3DP published in Nature Communications!
This paper is our initial demonstration of multimaterial vat photopolymerization using “a chemist’s bottom-up approach.” We look forward to expanding the materials scope, chemical space, and collaborative efforts on this program. Here is a link …
AJB is now an affiliate faculty member in CBE!
The Chemical and Biological Engineering Department has appointed AJ as an affiliate faculty member. We’re looking forward to exciting interdisciplinary work and interdepartmental activities.
Making PNB from…PNB? Yep.
Congrats to Daniel Lee and Tori Kensy! Their work, in collaboration with Prof. Brian Long and Christopher Maroon (each at UT-Knoxville), was just accepted for publication in Angewandte Chemie. This paper describes the mechanochemical conversion …
The Intrinsic Mechanochemical Reactivity of Vinyl-Addition Polynorbornene
Herein we report the discovery of the intrinsic mechanochemical reactivity of vinyl-addition polynorbornene (VA-PNB), which has strained bicyclic ring repeat units along the polymer backbone. VA-PNBs with three different side chains were found to undergo ring-opening olefination upon sonication in dilute solutions. The sonicated polymers exhibited spectroscopic signatures consistent with conversion of the bicyclic norbornane repeat units to the ring-open isomer typical of polynorbornene made by ring-opening metathesis polymerization (ROMP-PNB). Thermal analysis and evaluation of chain scission kinetics suggest that sonication of VA-PNB results in chain segments containing a statistical mixture of vinyl-added and ROMP-type repeat units.
Congratulations on Johanna Schwartz’s First Prize Poster!
Congratulations to Johanna Schwartz who won first prize for her poster, titled “Multimaterial Actinic Spatial Control (MASC) Digital Light Processing Additive Manufacturing” at the University of Wisconsin Workshop on Additive Manufacturing. The workshop featured talks …
Dr. Hang Shen joins the Boydston Research Group
We are exciting to welcome Dr. Hang Shen to the team. Hang’s expertise is in new reaction development and synthetic organic methods. He plans to expand his skill set and help drive our program in …
The Group is growing!
The group welcomes first-year graduate students Rachel Tritt, Sean Gitter, Vinnie Rigoglioso, and Cody Schilling. We’re all exciting to have outstanding new team members.
Metal-Free ROP-ROMP! Check out Pengtao’s latest communication.
Congratulation to Pengtao Lu on his just-accepted manuscript in Polymer Chemistry. This work will be part of a themed issue on Pioneering Investigators 2019 and teaches methods for synthesizing ROP-ROMP block copolymers in entirely metal-free …
Integration of Metal-Free Ring-Opening Metathesis Polymerization and Organocatalyzed Ring-Opening Polymerization through a Bifunctional Initiator
We have investigated the use of metal-free ring-opening metathesis polymerization (MF-ROMP) in combination with organocatalyzed ring-opening polymerization (o-ROP) to produce diblock copolymers with highly disparate block compositions via exclusively metal-free methods. Use of a bifunctional initiator bearing a vinyl ether as organic initiator for MF-ROMP and an alcohol for initiation of o-ROP allowed for investigation of three synthetic approaches: 1) sequential polymerization with isolation of the intermediate macroinitiators, 2) simultaneous bidirectional polymerizations, and 3) “one-pot” sequential monomer addition. Macroinitiators formed by first conducting o-ROP were successfully used in subsequent MF-ROMP to prepare diblock copolymers. Simultaneous MF-ROMP and o-ROP was thwarted by incompatible cross-combinations of catalysts and monomers. Finally, a straightforward “one-pot” synthesis of block copolymers, using o-ROP followed by MF-ROMP, was realized by sequential addition of each monomer-catalyst combination.