ATRP Catalyst Removal and Ligand Recycling Using CO2-Switchable Materials

Progress Toward Sustainable Reversible Deactivation Radical Polymerization

The recent focus of media and governments on renewability, green chemistry, and circular economy has led to a surge in the synthesis of renewable monomers and polymers. In this review, focussing on renewable monomers for reversible deactivation radical polymerizations (RDRP), it is highlighted that for the majority of the monomers and polymers reported, the claim to renewability is not always accurate. By closely examining the sustainability of synthetic routes and the renewability of starting materials, fully renewable monomers are identified and discussed in terms of sustainability, polymerization behavior, and properties obtained after polymerization. The holistic discussion considering the overall preparation process of polymers, that is, monomer syntheses, origin of starting materials, solvents used, the type of RDRP technique utilized, and the purification method, allows to highlight certain topics which need to be addressed in order to progress toward not only (partially) renewable, but sustainable monomers and polymers using RDRPs.

CuBr2/EDTA-mediated ATRP for ultrasensitive fluorescence detection of lung cancer DNA

In this paper, we reported a system for the ultrasensitive fluorescence detection of cytokeratin fragment antigen 21-1 DNA (CYFRA21-1 DNA) for the early diagnosis of lung cancer. The approach used electron transfer atom transfer radical polymerization (ARGET-ATRP) with ethylenediaminetetraacetic acid (EDTA) as the metal ligand. Firstly, thiolated peptide nucleic acid (PNA) was linked to aminated magnetic beads solutions (MBs) by a cross-linking agent and then hybridized with CYFRA21-1 DNA (tDNA). Subsequently, Zr4+ was introduced into the MBs by conjugating with the phosphate group of tDNA, and the initiator of ARGET-ATRP was introduced into via phosphate-Zr4+-carboxylate chemistry. Next, Cu(II)Br/EDTA was reduced to Cu(I)/EDTA by ascorbic acid (AA) to trigger ARGET-ATRP and then a large amount of fluorescein-o-acrylate (FA) molecules were grafted from the surface of the MBs, which amplified significantly the fluorescent signal. Under optimal conditions, a strong linear relationship of tDNA over the range from 0.1 fM to 1 nM (R2 = 0.9988). The limit of detection was as low as 23.8 aM (~143 molecules). The fluorescence detection based on the ARGET-ATRP strategy yielded excellent sensitivity, selectivity, outstanding anti-interference properties, and cost-effectiveness. These results indicated that this strategy has considerable potential for biological detection and early clinical diagnosis.

Designing a robust recyclable tricopolymer poly(ionic liquid) macroligand for copper-mediated atom transfer radical polymerization in non-aqueous biphasic systems

Herein, a robust thermoregulated poly(ionic liquid) macroligand was designed, synthesized and applied in an ICAR-based ATRP-TPSC system with efficient recycling/reuse.

An isocyanide ligand for the rapid quenching and efficient removal of copper residues after Cu/TEMPO-catalyzed aerobic alcohol oxidation and atom transfer radical polymerization

Three for the price of one: 1,4-bis(3-isocyanopropyl)piperazine allows for the removal of Cu impurities, can quench Cu-catalyzed reactions, and can prevent undesirable Glaser coupling.

Nitroxide-Mediated Copolymerization of Itaconate Esters with Styrene

Replacing petro-based materials with renewably sourced ones has clearly been applied to polymers, such as those derived from itaconic acid (IA) and its derivatives. Di-n-butyl itaconate (DBI) was (co)polymerized via nitroxide mediated polymerization (NMP) to impart elastomeric (rubber) properties. Homopolymerization of DBI by NMP was not possible, due to a stable adduct being formed. However, DBI/styrene (S) copolymerization by NMP at various initial molar feed compositions fDBI,0 was polymerizable at different reaction temperatures (70–110 °C) in 1,4 dioxane solution. DBI/S copolymerizations largely obeyed first order kinetics for initial DBI compositions of 10% to 80%. Number-average molecular weight (Mn) versus conversion for various DBI/S copolymerizations however showed significant deviations from the theoretical Mn as a result of chain transfer reactions (that are more likely to occur at high temperatures) and/or the poor reactivity of DBI via an NMP mechanism. In order to suppress possible intramolecular chain transfer reactions, the copolymerization was performed at 70 °C and for a longer time (72 h) with fDBI,0 = 50%–80%, and some slight improvements regarding the dispersity (Ð = 1.3–1.5), chain activity and conversion (~50%) were observed for the less DBI-rich compositions. The statistical copolymers produced showed a depression in Tg relative to poly(styrene) homopolymer, indicating the effect of DBI incorporation.

Synthesis of chitosan-mimicking cationic glycopolymers by Cu(0)-LRP for efficient capture and killing of bacteria

A schematic representation of the preparation of cationic magnetic glyconanoparticles by Cu(0)-LRP to efficiently capture, kill and separate E. coli from water.