3 research outputs found
Fabrication of Multifunctional Electronic Textiles Using Oxidative Restructuring of Copper into a Cu-Based MetalāOrganic Framework
This paper describes a novel synthetic approach for the conversion of zero-valent copper metal into a conductive two-dimensional layered metalāorganic framework (MOF) based on 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) to form Cu3(HHTP)2. This process enables patterning of Cu3(HHTP)2 onto a variety of flexible and porous woven (cotton, silk, nylon, nylon/cotton blend, and polyester) and non-woven (weighing paper and filter paper) substrates with microscale spatial resolution. The method produces conductive textiles with sheet resistances of 0.1ā10.1 MĪ©/cm2, depending on the substrate, and uniform conformal coatings of MOFs on textile swatches with strong interfacial contact capable of withstanding chemical and physical stresses, such as detergent washes and abrasion. These conductive textiles enable simultaneous detection and detoxification of nitric oxide and hydrogen sulfide, achieving part per million limits of detection in dry and humid conditions. The Cu3(HHTP)2 MOF also demonstrated filtration capabilities of H2S, with uptake capacity up to 4.6 mol/kgMOF. X-ray photoelectron spectroscopy and diffuse reflectance infrared spectroscopy show that the detection of NO and H2S with Cu3(HHTP)2 is accompanied by the transformation of these species to less toxic forms, such as nitrite and/or nitrate and copper sulfide and Sx species, respectively. These results pave the way for using conductive MOFs to construct extremely robust electronic textiles with multifunctional performance characteristics
A polycationic pillar[5]arene for the binding and removal of organic toxicants from aqueous media
The ability to bind and detect analytes with high levels of selectivity, sensitivity and broad applicability for a variety of analytes is an essential goal, with applications in public health and environmental remediation. Methods to achieve effective binding and detection include electrochemical, and spectroscopic methods. The use of supramolecular chemistry to accomplish such detection, by binding a target in a host and transducing that binding into a measurable signal, has advantages, including tunability of the sensor and the ability to rationally design hosts through an understanding of non-covalent interactions. Reported herein is the design and use of pillar[5]arenes to accomplish precisely such detection. Water-soluble pillar[5]arenes containing 10 cationic linker arms on their periphery bound toxicants in their hydrophobic cores with association constants of 105ā106Mā1. With the use of cationic exchange resins, the pillar[5]arene hosts were removed from solution with their encapsulated guests, allowing for effective toxicant removal
Ancillary Ligand Lability Improves Control in Cyclic Ruthenium Benzylidene Initiated Ring-Expansion Metathesis Polymerizations
The synthesis of well-defined cyclic polymers is crucial
to exploring
applications spanning engineering, energy, and biomedicine. These
materials lack chain-ends and are therefore imbued with unique bulk
properties. Despite recent advancements, the general methodology for
controlled cyclic polymer synthesis via ring-expansion metathesis
polymerization (REMP) remains challenging. Low initiator activity
leads to high molar mass polymers at short reaction times that subsequently
āevolveā to smaller polymeric products. In this work,
we demonstrate that in situ addition of pyridine
to the tethered ruthenium-benzylidene REMP initiator CB6 increases ancillary ligand lability to synthesize controlled and
low dispersity cyclic poly(norbornene) on a short time scale without
relying on molar mass evolution events