Herb has successfully defended his thesis, "Synthesis and Reactivity of Azaborine and Silicon Molecules for Polymeric Materials". Congratulations Dr. Wakefield!

A team from the Steinmetz  and Nelson  labs  introduce a 3D-printable virus-like particle (VLP)-enhanced cross-linked biopolymer system. VLPs displaying surface-available acrylate groups were prepared through aza-Michael addition to serve as resins. The VLP resins were then photopolymerized into a poly(ethylene glycol) diacrylate (PEGDA) network following DLP 3D printing. This approach represents a convergence of disciplines, where the synergistic interaction between virology and additive manufacturing unlocks new frontiers in biotechnology. Article Link

Ilia Kevlishvili (Kulik lab postdoc) and Shixuan Wei (Campos lab graduate student) have been elected as trainee representatives to the Year 3 leadership team. Ilia will be responsible for trainee engagement, and Shixuan will work in Higher Education & Professional Development. Thanks to them both and to Yunyan Sun who will rotate off after two years of service.

Some of the MONET team meet to explore Mission Bay and talk science before the ACS Spring Meeting 2022 in San Diego.

A team from the Olsen and Johnson labs use small angle neutron scattering to measure single chain radii of gyration of end-linked polymer gels before and after cross-linking to calculate the prestrain, which is the ratio of the average chain size in a cross-linked network to that of a free chain in solution. Prestrain measurements reported serve as a point of reference for network theories that rely on this parameter for the calculation of mechanical properties. Article Link

A team from the Rubinstein lab develop a single-chain model to account for the redistribution of monomers between network strands of a primary chain. The model takes into account both the pulley effect and fluctuations in the number of monomers per network strand.  The model will allow for a more systematic analysis of collective and pairwise entanglements in the future. Article Link

A team from the Rubinstein and Craig labs present a modified Lake–Thomas theory that accounts for the molecular details of network connectivity upon crack propagation in polymer networks. In comparison with the “strong” mechanophores that can only be activated in the bridging strand, “weak” mechanophores that can be activated both in the bridging strand and in other generations could provide more energy dissipation due to their larger contribution to higher generations of the tree. Article Link

A team from the Craig and Olvera de la Cruz labs report a polyelectrolyte handle for single-molecule force spectroscopy that offers a combination of high attachment forces, good success in obtaining a high-force attachment, a non-fouling detachment process that allows for repetition, and specific attachment locations along the polymer analyte. The polyelectrolyte handle approach will prove useful for selected applications in covalent polymer mechanochemistry. Article Link

A team from the Craig and Johnson labs use mechanophore force probes with discrete molecular weights to determine how the deformation and tension experienced by a strand is influenced by strand length. The combination of discrete strand synthesis and mechanochromism provides a foundation to further test and develop molecular-based theories of elasticity and fracture in polymer networks. Article Link

MONET JHU trainee Herb Wakefield gave an invited talk on "Precise Synthesis and Reactivity of Organometallic Building BLocks of Novel Polymers" at Kenyon College. Following the talk, Herb discussed the process to choose and apply to grad schools with undergraduates in the departments of Chemistry and Biochemistry & Molecular Biology.

A team from the Klausen, Johnson, Craig, and Kulik labs report the geometrically selective synthesis of trans- and cis-silacycloheptenes via a novel synthetic strategy and probe the effect of Si for C substitution on ring-opening metathesis polymerization (ROMP). The results point to the possibility of employing Si-rich polymers to prove the contribution of strand elasticity to the mechanical properties of bulk polymer networks. Article Link

A team from the Steinmetz and Craig labs investigate the effects of linear and multivalent polyethylene glycol (PEG) coatings on the tobacco mosaic virus (TMV) at varying chain lengths on serum protein adsorption, antibody recognition, and macrophage uptake. The work provides insight into the PEGylation of virus-based nanoparticles (VNPs), which may improve the possibility of their implementation in clinical applications. Article Link