NEWS
[03/10/2015]We report poly(sarcosine-r-N-butylglycine) [P(Sar-r-NBG)] random copolymers with various MWs and compositions polymerized of Sar-NTA with NBG-NTA in THF at 60 oC initiated by benzylamine. It is the first report to synthesize polypeptoids with DP over 150 by primary amine-initiated NTA polymerization. MWs and compositions of polypeptoids can be easily controlled by feed molar ratio of [Sar]/[NBG]/[benzylamine]. P(Sar-r-NBG)s are thermoresponsive materials exhibiting reversible Tcp from 27-71 oC in aqueous solution. Tcps exhibit linear relationship with copolymer compositions. The dependence of Tcps of P(Sar-r-NBG)s is also systematically investigated on the corresponding polymer MWs, concentrations, and salt additives. The cytotoxicity of P(Sar-r-NBG)s is related to composition of polypeptoids, which can find applications in killing tumor cells together with heat therapy. This work was published on Polymer Chemistry (Publication #91).
[09/02/2014] We reported a styrene-type macromonomer containing polyfluorene pendent group (PFS), which allowed the convenient synthesis of well-defined copolymers of PFS with t-butyl acrylate by both RAFT and ATRP. After hydrolysis, the amphiphilic copolymers self-assembled into photoluminescent nanoparticles in aqueous solution. When doped with selected dyes, the nanoparticles emitted lights with tunable colors as well as white via Förster energy transfer from the excited pendent polyfluorene groups. This work was published on Polymer Chemistry, and selected as "paper of the week" (Publication #80). The first author is Chao Deng.
[05/10/2014] Xinfeng Tao’s work (Publication #77) was published on May 2, 2014, and selected as the front cover of the 9th issue of Macromol Rapid Commun. We report a controlled ROP of Sarcosine-NTA to develop a versatile and practical synthetic method to prepare well-defined polyether-polypeptoids with designable chain lengths of PSar blocks. PEG-b-PSar products are novel dual-hydrophilic diblock copolymers that are able to emulsify organic droplets in water at nano- and micro-scale, and also to self-assemble into micelles in selected organic solvents with different morphologies. Easily accessible, nontoxic, biocompatible and biodegradable PEG-b-PSar polymers as potential biomaterials deserve more detailed investigation.
[04/10/2014] Is it possible to combine cationic and (coordinated) anionic ring opening polymerizations (i.e. CROP and AROP) into a unimolecular chain? We put forward the concept of “Janus polymerization”. It shall essentially comprise a controlled chain-growth polymerization and the subsequently step-growth polymerization, which, as a consequence, is a feasible way to afford well-defined multiblock copolymers directly from two monomers in a one-step process. As an evidence, simultaneous cationic copolymerization of tetrahydrofuran (THF) with e-caprolactone (CL) and AROP of CL are carried out on the two ends of a single growing chain, and produce multiblock copolymers via polycondensation. This work was accepted for publication by Macromolecules (Publication #76).
[03/11/2014] Congratulations to Jin-ou Lin and Xuemei Zhang who passed the M.Sc. defense.
[01/21/2014] We report a novel rod-like nano-light harvester (NLH) based on cylindrical core-shell polymer brush (CPB) architecture. By modifying different light-absorbing antennae and energy acceptors, NLH can be applied to any energy capture applications. This work was accepted for publication by Macromol. Rapid Commun. (Publication #67).
[12/05/2013] We developed a novel template-directed approach based on core-shell cylindrical polymer brushes and successfully prepared rare-earth metal cations (Ln3+) incorporated silica hybrid nanoparticles (NPs) with predictable dimensions. As expected, the silica hybrid NPs obtained unique and diverse properties from the incorporated Ln3+ ions. This work was accepted for publication by Chemistry of Materials (Publication #66).
[11/13/2013] We developed a facile "CTA-shuttled" R-group approach to overcome the "entrapment effect" and thus prepared well-defined cylindrical polymer brushes (CPBs) from linear polyCTAs via RAFT polymerization. Both the experiment and the Monte Carlo simulation confirm the advantage of this novel R-group approach. This work was accepted for publication by Macromol. Rapid Commun. (Publication #68).
[10/24/2013] It's a great honor for us to invite Prof. Thieo E. Hogen-Esch to attend our seminar on Oct. 7th. Also he gived lectures titled in "Self-assembly of perfluorocarbon functionalized polymers. Solution and blends" and "Synthesis and photochemical properties of vinylaromatic polymers" respectively to the students in our department on Oct. 9th and 11th.
[09/07/2013] We used rare earth catalysts to polymerize ε-decalactone (DL), a bio-based material, with L-lactide (LLA). Multiblock copolymer of DL and LLA were obtained by chain extension reaction, which exhibited excellent elongation up to 723%. This bio-based, biodegradable and biocompatible elastomer was expected to have medical applications. This work was accepted for publication by Macromolecules on Sep. 6th (Publication #65).
[09/07/2013] Three new members, Yangwei Deng, Junhua Liu and Xiaoqing Wang have joined us since this new semester. Wish them a happy and fruitful stay with all of us.
[06/17/2013] Congratulations to Yangwei Deng, Xiaobin Shen and Wei Zhang who passed the BSc defense on Jun. 17, 2013.
[03/13/2013] Congratulations to Yipin Lin who passed the M.Sc. defense.
[02/22/2013] Cylindrical polymer brushes (CPBs) have unique chemical and physical properties due to their interesting topologies including stretched backbones, crowded side chains and high end group densities. Core-shell CPBs with well-designed side chain compositions act as a "battle field" for direct “fight” of weak intermolecular interactions and strong carbon-carbon covalent bonds. Our manuscript of a controlled scission behavior of CPBs on substrate surface was accepted for publication by ACS Nano on Feb. 13th (Publication #61
).
[10/20/2012] Very recently we synthesized a new monomer, 9,9-diethylfluoren-2-yl methyl methacrylate (FMMA) and its well-defined homopolymer PFMMA, block and random copolymers PDMAEMA-co-PFMMA. The PDMAEMA-b-PFMMA amphiphilic diblock copolymers showed self-assembly into spherical micelles with uniform size. The PFMMA core showed photoluminescence when carrying dichloromethane "guest" molecules and its emission was quenched after the release of the guests. This work was accepted for publication by J. Colloid Interf. Sci. on Sep. 26th (Publication #59
).
[09/11/2012] Three new members, Ce Tian, Zhe'ning Yang and Chao Deng have joined us since this new semester. Wish them a happy and fruitful stay with all of us.
[08/27/2012] The image of Hui Peng's work on the deprotonation of NCA at 4-position (Publication #53) was selected as the front cover of the 18th issue
of J. Polym. Sci. Part A: Polym. Chem. to be published on Sep. 15th, 2012.
[08/27/2012] Although many catalysts for cationic polymerization of THF have been reported, study on novel catalyst is still an important topic since PTHF is very useful. Recently Lixin You found rare earth triflates are very efficient catalysts for controlled THF polymerization in the presence of epoxides. The most exciting advantage is that scandium compound is quantitatively recyclable, which makes it a real catalyst. This work has been published in Polymer 2012, 53, 4112-4118. (Publication #56
)
[07/04/2012] Congratulations to Yipin Lin who was granted DAAD fellowship sponsored by German government. She will be an exchange graduate student from July to September in University of Bayreuth. Wish her a successful stay in Germany!
[07/04/2012] The image of Hui Peng's work on the NCA polymerization initiated by rare earth tris(borohydride) complexes (Publication #52) was selected as the inside cover of the 15th issue
of J. Polym. Sci. Part A: Polym. Chem. to be published on Aug. 1st.
Congratulations to Zhening Yang who passed the BSc defense on Jun. 8, 2012 scored "Excellence".
Congratulations to Hui Peng who passed the Ph.D. defense on Jun. 3, 2012 scored "Excellence".
The deprotonation of 4-CH group in α-amino acid N-carboxyanhydride (NCA) molecules has been neglected for decades. Some researchers regard it “very unlikely”. Our recent work provides direct evidence to support the acidity of 4-CH in NCA and has been accepted for publication by J. Polym. Sci. Part A: Polym. Chem. on Apr. 19, 2012 (Publication #53).
Hui Peng's paper entitled "Polymerization of α-amino acid N-carboxyanhydrides catalyzed by rare earth tris(borohydride) complexes: mechanism and hydroxy-endcapped polypeptides" was accepted to publish by J. Polym. Sci. Part A: Polym. Chem. on Mar. 21, 2012 (Publication #52). This work demonstrated a new application of rare earth catalysts in the ring-opening polymerization of NCAs. Detailed studies on mechanism required skillful experimental techniques. "You have performed a very good piece of work!", commented Professor Hans R. Kricheldorf.
Congratulations to Xin Li who passed his master degree defense on Mar. 17, 2012.
The article of NCA polymerization by rare earth catalysts (Publication #49) was shown on the front cover of J. Polym. Sci. Part A: Polym. Chem. (2012) Vol 6. Congratulations to Hui Peng!
Catalyzed by yttrium trisphenolate, polymerization of ε-caprolactone was directly initiated by hydroxyl groups of unmodified cyclodextrin. The cyclodextrin-centered multiarmed polycaprolactones (PCL) showed tunable thermal behaviors and solubilities depending on the length of PCL arms. Xin Li's work was accepted to publish by Macromol. Rapid Commun. on Jan. 31, 2012 (Publication #51).
|
