PREDICTION OF THE RHEOLOGICAL PROPERTIES OF STAR—TYPE BRANCHED POLYMER SOLUTIONS BY MEANS OF THE FIXED SPECTRUM MODEL

The Rouse-Zimm model with slippage was improved and the basic parameters of modelwere modified to explain the rheological properties of star-type branched polymersolutions. The theoretical results show good agreement with experimental data.

Coupling WO_(3-x) dots-encapsulated metal-organic frameworks and template-free branched polymerization for dual signal-amplified electrochemiluminescence biosensing

Developing accurate and sensitive DNA methyltransferase(MTase) analysis methods is essential for early clinical diagnosis and development of antimicrobial drug targets. In this work, by coupling WO_(3-x) dotsencapsulated metal-organic frameworks(MOFs) as co-reactants and terminal deoxynucleotidyl transferase(Td T)-mediated template-free branched polymerization, a dual signal-amplified electrochemiluminescent(ECL) biosensor was constructed to detect DNA adenine methylation(Dam) MTase. The employment of WO_(3-x) dots-encapsulated MOFs(i.e., NH_(2)-UIO66@WO_(3-x) ) was not only beneficial for biomolecule conjugation because of the abundant amino groups but also led to a 7-fold enhanced ECL response due to the increased loading of WO_(3-x). Moreover, Td T-mediated template-free branched polymerization promoted the capture of ECL emitters on the electrode surface, achieving 20-fold enhanced signal amplification. The presented ECL biosensor demonstrated a low detection limit of 2.4 × 10^(-4)U/m L, and displayed high reliability for the detection of Dam MTase in both spiked human serum and E. coli cell samples, and for the screening of potential inhibitors. This study opens a new avenue for designing a dual signal amplificationbased ECL bioassay for Dam MTase and screening inhibitors in the fields of clinical diagnosis and drug development.

Synthesis and characterization of well-defined comb-like branched polymers

Well-defined comb-like branched polymers having one branch in each repeating unit have been suc-cessfully synthesized by the coupling reaction of living polystyrene(PS)and polyisoprene(PI)anions with 1,1-diphenylethenyl(DPE)groups along PS backbone pre-pared via atom transfer radical polymerization(ATRP)of 4-vinylbenzyloxy benzophenone(Sc)followed by Wittig reaction.The resulting comb-like branched poly-mers were characterized by IR,1H-NMR,gel permeation chromatography(GPC)and static light scattering(SLS)in detail.The effect of living chains and DPE group molar ratio on grafting efficiency was discussed.The results show the coupling reaction of living chains and DPE groups was highly effective,and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups.Moreover,the effect of molecular weights of backbone(PSe)and PSLi or PILi on grafting efficiency was also discussed.The results show that when excess living polymers were used,the almost quantitative grafting efficiency could be achieved.

Synthesis of Highly Branched Poly(ε-caprolactone) by Self-condensing Atom Transfer Radical Polymerization of Macroinimers

Branched poly（ε-capmlactone） was synthesized by self-condensing atom transfer radical polymerization of macroinimer, α-acryloyoxy-ω-2-bromopropionyloxy poly（ε-caprolactone）, which was prepared by enzyme-catalyzed ring-opening polymerization of ε-caprolactone with 2-hydroxylethyl acrylate as initiator and esterification of the ω-hydroxyl group of the obtained poly（ε-caprolactone） by 2-bromopropionyl bromide.

A branched dihydrophenazine-based polymer as a cathode material to achieve dual-ion batteries with high energy and power density

Organic electrode materials have exhibited good electrochemical performance in batteries,but their voltages and rate capabilities still require improvement to meet the increasing demand for batteries with high energy and power density.Herein,we design and synthesize a branched dihydrophenazine-based polymer(p-TPPZ)as a cathode material for dual-ion batteries(DIBs)through delicate molecular design.Compared with the linear dihydrophenazine-based polymer(p-DPPZ,with a theoretical capacity of 209 mAh g^(−1)),p-TPPZ possessed a higher theoretical capacity of 233 mAh g^(−1)and lower highest occupied molecular orbital energy levels,which resulted in a high actual capacity(169.3 mAh g^(−1)at 0.5 C),an average discharge voltage of 3.65 V(vs.Li+/Li)and a high energy density(618.2 Wh kg^(−1),based on the cathode materials).The branched structure of p-TPPZ led to a larger specific surface area than that of p-DPPZ,which was beneficial for the electrolyte infiltration and fast ionic transport,contributing to the high power density.Due to the fast reaction kinetics,even at a power density of 23,725 W kg^(−1)(40 C),the energy density still reached 474.5 Wh kg^(−1).We also made a detailed investigation of the p-TPPZ cathode’s charge storage mechanism.This work will stimulate the further molecular design to develop organic batteries with both high energy and power density.

Effects of Branching Strategy on the Gene Transfection of Highly Branched Poly(β-amino ester)s

Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene transfection performance have not yet been explored.Here,using triacrylate(B3)and diamine(B4)as the branching monomers,a series of HPAEs were synthesized via the"A2+B3+C2"and"A2+B4+C2"strategies,respectively.Results show that the branching strategy plays a pivotal role in dictating the physiological properties of the HPAE/DNA polyplexes and thus leads to obviously different cell viability and transfection efficiency.Comparatively,HPAEs synthesized via the"A2+B3+C2"branching strategy are more favorable for DNA transfection than that synthesized via the"A2+B4+C2"strategy.This study may provide new insights into the development of HPAEs based non-viral DNA delivery system.