A5047335957- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Luminescence and Fluorescent Materials
- Photochromic and Fluorescence Chemistry
- Crystallography and molecular interactions
- Organic Light-Emitting Diodes Research
- Organic Electronics and Photovoltaics
- Advanced Polymer Synthesis and Characterization
- Photochemistry and Electron Transfer Studies
- Polymer composites and self-healing
- Molecular Junctions and Nanostructures
- biodegradable polymer synthesis and properties
- Microplastics and Plastic Pollution
- Radical Photochemical Reactions
- Covalent Organic Framework Applications
- Physical Unclonable Functions (PUFs) and Hardware Security
- Synthetic Organic Chemistry Methods
- Polydiacetylene-based materials and applications
- Sulfur-Based Synthesis Techniques
- Green IT and Sustainability
- Nanocluster Synthesis and Applications
- Chemistry and Chemical Engineering
- Inorganic Chemistry and Materials
- Conducting polymers and applications
- Magnetism in coordination complexes
Lawrence Berkeley National Laboratory
2019-2022
University of British Columbia
2013-2019
Vancouver Biotech (Canada)
2019
Control of equilibrium and non-equilibrium thermomechanical behavior poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) conformational degrees freedom into the dynamic covalent network. While increasing MW yields a lower storage modulus at rubbery plateau after softening above glass transition (Tg ), both Tg characteristic time stress relaxation are independently governed entropy embodied segments. Activation energies for bond...
While not yet competitive with commodity polymers, PDKs are recycled to monomer at lower cost and emissions than virgin resins.
Footwear, carpet, automotive interiors, and multilayer packaging are examples of products manufactured from several types polymers whose inextricability poses substantial challenges for recycling at the end life. Here, we show that chemical circularity in mixed-polymer becomes possible by controlling rates depolymerization polydiketoenamines (PDK) over orders magnitude through molecular engineering. Stepwise deconstruction mixed-PDK composites, laminates, assemblies is chemospecific,...
A general approach to enhancing the emission quantum yield of several widely studied organic chromophores is presented. The luminescence properties a series symmetrical sulfur-bridged are reported as function oxidation state bridging sulfur atom. photoluminescence significantly enhanced by successively oxidizing bridge from sulfide (S), sulfoxide (SO), sulfone (SO2).
A new concept for difficult-to-replicate security inks use in advanced anti-counterfeiting applications is presented. Inks fabricated from a mixture of photoactive dyes result unique fluorescent color upon irradiation that differs the starting fluorescence. The are substituted 9,9'-dianthryl sulfoxides undergo photochemical extrusion sulfoxide moiety (SO) to produce emissive red, blue, and green emitters. resulting feature has specific Commission international de l'éclairage (CIE)...
Symmetric dimers have the potential to optimize energy transfer and charge separation in optoelectronic devices. In this paper, a combination of optical spectroscopy (steady-state time-resolved) electronic structure theory is used analyze photophysics sulfur-bridged terthiophene dimers. This class has unique feature that interchromophore (intradimer) coupling can be modified by varying oxidation state bridging sulfur from sulfide (S), sulfoxide (SO), sulfone (SO2). Photoexcitation leads...
What's up sulfur? The photochemical reactivity, including a mechanistic study of sulfur-bridged anthracenes is reported. oxidation state the bridging sulfur (SOn) dictates excited-state behavior these molecules (see picture). As service to our authors and readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized for online delivery, but not copy-edited or typeset. Technical support issues arising from (other than missing...
Abstract White‐light emitters have attracted considerable attention due to their importance in current and future technologies. By incorporating molecular fragments that independently emit the blue, green/yellow, red visible regions, specifically Cu‐NC, Au⋅⋅⋅Au interactions, Cu‐SR 2 , respectively, into a single material, new white‐light‐emitting systems been targeted. With this goal, three Cu I /thioether‐based coordination polymers containing bridging [Au(CN) ] − units synthesized...
New methods that yield covert fluorescent images are of significant interest for applications in anti‐counterfeit technology. Printing offer access to spatially controlled fluorescence intensity needed order accurately reproduce unique and complex images. Herein, the use photoreactive inks containing 9,9′‐ bis (anthracene)sulfoxide (AnSO) create with is presented. Under UV irradiation, SO‐bridge between anthracene units AnSO extruded highly luminescent molecule 9,9′‐bianthryl (BA)...
Covalently tethered bichromophores provide an ideal proving ground to develop strategies for controlling excited state behavior in chromophore assemblies. In this work, optical spectroscopy and electronic structure theory are combined demonstrate that the oxidation of a sulfur linker between anthracene chromophores gives control over not only photophysics but also photochemistry molecules. Altering does change geometry chromophores, allowing effects be isolated. Previously, we showed...
A series of donor–acceptor (D–A) and donor–acceptor–donor (D–A–D) molecules containing anthracene chromophores paired with a sulfur-containing acceptor group have been prepared. The oxidation state the sulfur atom controls degree charge transfer character in excited wave function. Steady-state photoluminescence spectroscopy shows more pronounced solvatochromism increasing state. Computational methods (DFT/TD-DFT) are used to show that orbital mixing between donor is facilitated as increased.
Abstract Control of equilibrium and non‐equilibrium thermomechanical behavior poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) conformational degrees freedom into the dynamic covalent network. While increasing MW yields a lower storage modulus at rubbery plateau after softening above glass transition (T g ), both T characteristic time stress relaxation are independently governed entropy embodied segments. Activation energies for...
Was macht der Schwefel? Über die photochemische Reaktivität einschließlich mechanistischer Studien Schwefel-verbrückter Anthracene wird berichtet. Der Oxidationszustand des verbrückenden Schwefels (SOn) bestimmt das Verhalten Moleküle im angeregten Zustand (siehe Bild).