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An antibacterial and antifouling surface is obtained by simple one-step immersion of a catheter surface with brush-like polycarbonates containing pendent adhesive dopamine, antifouling polyethylene glycol (PEG), and antibacterial cations. This coating demonstrates excellent antibacterial and antifouling activities against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, proteins, and platelets, good stability under simulated blood-flow conditions, and no toxicity.

All solvents were purchased from Thermo Fisher Scientific Inc. and used without further purification unless otherwise noted. All other chemicals were purchased from Sigma Aldrich Co., Alfa Aesar, or Thermo Fisher Scientific Inc., and were used as received. THF was dried over 3 Å molecular sieves and deoxygenated using a Vacuum Atmospheres Company solvent purification system. 2,5-Dibromo-3-hexylthiophene was prepared according to literature procedures. 1 All manipulations were performed under nitrogen using standard Schlenk techniques. 1 H NMR spectra were recorded using a Varian 400 or 500 MHz spectrometer. Chemical shifts are reported in delta (δ) units and expressed in parts per million (ppm) downfield from tetramethylsilane using the residual non-deuterated solvent as an internal standard. For 1 H NMR: CDCl 3 , 7.24 ppm. Gel permeation chromatography (GPC) was performed at 40°C on a GPCmax VE-2001 (Viscotek) equipped with solvent and sample delivery module, and three fluorinated polystyrene columns (IMBHW-3078 and I-MBMMW-3078 and

A modular and convenient synthesis of ethynyl end functionalized poly(3-hexylthiophene) in high purity is reported; this material facilitated access to poly(3-hexylthiophene)-block-poly(acrylic acid) which self-assembled into hierarchical structures.

Herein, we describe a catalyst transfer polycondensation that enabled access to well-defined poly(p-phenyleneethynylene) (PPE), a prominent conjugated polymer. Treatment of a stannylated 4-iodophenylacetylene derivative with PhPd(t-Bu3P)Br afforded the corresponding PPE in up to 94% yield. Under optimized conditions, the molecular weight of the polymer increased linearly with monomer consumption, and was controlled by adjusting the initial monomer-to-catalyst ratio. The chain-growth nature of the polymerization reaction was utilized to produce well-defined PPE-containing block copolymers, as well as to grow PPE brushes from silica nanoparticles via a surface-initiated polymerization process.

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Block copolymers of poly(3-hexylthiophene) and a poly(arylisocyanide) were synthesized in a single pot via the addition of 2-bromo-3-hexyl-5-chloromagnesiothiophene followed by n-decyl 4-isocyanobenzoate to a solution of Ni(1,3-bis(diphenylphosphino)propane)Cl(2). The respective mechanistically distinct polymerizations proceeded in a controlled fashion and afforded well-defined block copolymers with tunable molecular weights and compositions. The block copolymers exhibited microphase separation characteristics in the solid state.

Conjugated polymers in the solid state usually exhibit low fluorescence quantum yields, which limit their applications in many areas such as light-emitting diodes. Despite considerable research efforts, the underlying mechanism still remains controversial and elusive. Here, the nature and properties of excited states in the archetypal polythiophene are investigated via aggregates suspended in solvents with different dielectric constants (ɛ). In relatively polar solvents (ɛ>∼ 3), the aggregates exhibit a low fluorescence quantum yield (QY) of 2–5%, similar to bulk films, however, in relatively nonpolar solvents (ɛ<∼ 3) they demonstrate much higher fluorescence QY up to 20–30%. A series of mixed quantum-classical atomistic simulations illustrate that dielectric induced stabilization of nonradiative charge-transfer (CT) type states can lead to similar drastic reduction in fluorescence QY as seen experimentally. Fluorescence lifetime measurement reveals that the CT-type states exist as a competitive channel of the formation of emissive exciton-type states.