558484-21-2Relevant academic research and scientific papers
N, N-Dimethyl-Substituted Boron Ketoiminates for Multicolor Fluorescent Initiators and Polymers
Yang, Dong,Liu, Pei,Bai, Ting,Kong, Jie
, p. 3339 - 3348 (2020/04/20)
In this contribution, an efficient synthesis strategy of multicolor fluorescent N,N-dimethyl-substituted boron ketoiminates (NBKI) was presented. The introduction of dimethylamino group as donor and NOBF2 moiety as acceptor with variously tunable substituents led to the formation of D (donor)-π-A (acceptor) system in NBKI molecules, which exhibited a high fluorescence efficiency and a significant red shift of absorption/emission in solution. NBKI molecules were applied in the synthesis of multicolor fluorescent ATRP initiators (i-NBKI 1-4) and RAFT initiator (i-NBKI 5), as well as multicolor fluorescent PS, PMMA, PDBA, or PEG-based homopolymers/copolymers. It was demonstrated that PEG-based polymers showed effective fluorescence emission, good water solubility, and great potential in biological applications. This work bridges the gap in current organoboron compounds and multicolor fluorescent polymerization initiators and related fluorescent polymers/copolymers by utilizing D-π-A design. It may shed light on the downstream applications in next-generation multicolor fluorescent probes/devices.
Aqueous Biphasic Systems Containing Customizable Poly(Ionic Liquid)s for Highly Efficient Extractions
Ke, Yuqi,Ren, Qilong,Xie, Yuanbang,Xing, Huabin,Yang, Qiwei,Zhang, Jingzhu
, (2020/03/11)
Ionic liquid (IL)-based aqueous biphasic systems (ABSs) provide a sustainable and efficient alternative to conventional liquid–liquid extraction techniques and can be used for the extraction, recovery, and purification of diverse solutes. However, the construction of a high-performance ABS that has both excellent phase separation ability and extraction performance remains challenging. This study concerns the preparation of a family of novel ABSs based on poly(ionic liquid)s (PILs) with customized structure and controllable molecular weight for the extraction of bioactive compounds. Several tailor-made PILs consisting of a hydrophobic backbone, hydrophilic imidazolium pendant groups and strong hydrogen bonding basic counteranions are prepared by reversible addition fragmentation chain-transfer polymerization. The PILs have a perfect balance of hydrophobicity/hydrophilicity and functionality, affording outstanding phase separation, which was better than with either the IL monomer poly(1-butyl-3-vinylimidazolium bromide ([BVIm]Br) or the normal free-radical polymer P[BVIm]Br*. More importantly, PIL-based ABSs exhibited unprecedented high partition coefficients for six bioactive compounds including tryptophan, phenylalanine, and caffeine, as well as high extraction yields. The performance of the PIL-based ABSs could also be tuned by changing the molecular weight and anionic character of the PILs. This work shows that tailor-made PIL-based ABSs are a promising platform for bioactive compound extraction and provides significant clues for the design of new ABSs for various applications.
Synthesis of block and graft copolymers of styrene by raft polymerization, using dodecyl-based trithiocarbonates as initiators and chain transfer agents
Ponnusamy, Kannukaran,Babu, Rajendran Prakash,Dhamodharan, Raghavachari
, p. 1066 - 1078 (2013/08/24)
A series of dodecyl-based monofunctional trithiocarbonate chain transfer agents (CTAs) were successfully synthesized, toward the reversible addition-fragmentations chain transfer (RAFT) polymerization of styrene. The CTAs were used as initiators for RAFT
Ab initio emulsion polymerization by RAFT-controlled self-assembly
Ferguson, Christopher J.,Hughes, Robert J.,Nguyen, Duc,Pham, Binh T.T.,Gilbert, Robert G.,Serelis, Algirdas K.,Such, Christopher H.,Hawkett, Brian S.
, p. 2191 - 2204 (2007/10/03)
A method is developed to enable emulsion polymerization to be performed under RAFT control to give living character without the problems that often affect such systems: formation of an oily layer, loss of colloidal stability, or loss of molecular weight control. Trithiocarbonate RAFT agents are used to form short stabilizing blocks from a water-soluble monomer, from which diblocks can be created by the subsequent polymerization of a Hydrophobic monomer. These diblocks are designed to self-assemble to form micelles. Polymerization is initially performed under conditions that avoid the presence of monomer droplets during the particle formation stage and until the hydrophobic ends of the diblocks have become sufficiently long to prevent them from desorbing from the newly formed particles. Polymerization is then continued at any desired feed rate and composition of monomer. The polymer forming in the reaction remains under RAFT control throughout the polymerization; molecular weight polydispersities are generally low. The number of RAFT-ended chains within a particle is much larger than the aggregation number at which the original micelles would have self-assembled, implying that in the early stages of the polymerization, there is aggregation of the micelles and/or migration of the diblocks. The latexes resulting from this approach are stabilized by anchored blocks of the hydrophilic monomer, e.g., acrylic acid, with no labile surfactant present. Sequential polymerization of two hydrophobic monomers gives completely novel core - shell particles where most chains extend from the core of the particles through the shell layer to the surface.
