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Chain End-Functionalized Polymer Brushes with Switchable Fluorescence Response
摘要： Herein is described the switchable fluorescence response of poly(methyl methacrylate) (PMMA) brushes. Chain end fluorescein labeled PMMA brushes are prepared by combining surface-initiated atom transfer radical polymerization (SI-ATRP) with a copper-catalyzed alkyne-azide cycloaddition (CuAAC) click reaction. Successful attachment of fluorescein is confirmed by measuring fluorescence of the as-prepared films. Utilizing co-solvency of PMMA in isopropanol-water mixtures, responsive behavior of the end-functionalized brushes is demonstrated by measuring the changes in fluorescence intensity between the swollen and collapsed states.
关键词： fluorescent polymers,polymer brushes,co-solvency,solvent responsiveness
更新于2025-09-23 15:23:52
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Fluorescent patterns by Selective Grafting of a Telechelic Polymer
摘要： The preparation of patterned ultrathin films (sub-10 nm) composed of end-anchored fluorescently-labeled poly(methyl methacrylate) (PMMA) is presented. Telechelic PMMA was synthesized utilizing activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and consecutively end-functionalized with alkynylated fluorescein by Cu-catalyzed azide-alkyne cycloaddition (CuAAC) 'click' chemistry. The polymers were grafted via the α-carboxyl groups to silica or glass substrates pre-treated with (3-aminopropyl)triethoxysilane (APTES). Patterned surfaces were prepared by inkjet printing of APTES onto glass substrates and selectively grafted with fluorescently end-labeled PMMA to obtain emissive arrays on the surface.
关键词： ATRP,inkjet printing,click chemistry,grafting to,polymer brushes
更新于2025-09-19 17:15:36
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Metal-free and photo-controlled fabrication of fluorinated anti-fouling film
摘要： We reported a new photo-controlled synthesis route to fabricate a fluorine-containing thin film for protecting the oxidation of indium tin oxide (ITO) and other derivatives such as the fluorine-doped tin oxide (FTO) coated glasses. A relatively inexpensive, color/metal-free organic phenothiazine-based photocatalyst for atom transfer radical polymerization (ATRP) was successfully adopted by an ultraviolet light source to modified substrates. The fluorine thin film had a contact angle (CA) with water of 105.1°, an advancing angle of 112.2°, and a receding angle of 84.6°; leading to a hydrophobic nature with self-cleaning and anti-fouling properties. Our fluorinated conductive glass shows an optical transmittance up to 80 – 90% in the visible wavelength range. This work demonstrates the great value in the anti-fouling of electronics that secures itself from chemical contaminations in outdoor environments and use at high temperature and chemical erosions.
关键词： Atom Transfer Radical Polymerization (ATRP),ITO,Photo-controlled,Polymer brushes,FTO
更新于2025-09-12 10:27:22
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pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging
摘要： pH-Switchable, fluorescent, hybrid, water-dispersible nanomaterials based on boron nitride nanotubes (BNNTs) and grafted copolymer brushes (poly(acrylic acid-co-fluorescein acrylate) – P(AA-co-FA)) were successfully fabricated in a two-step process. The functionalization of BNNTs was confirmed by spectroscopic, gravimetric and imaging techniques. In contrast to “pure” BNNTs, P(AA-co-FA)-functionalized BNNTs demonstrate intense green fluorescence emission at 520 nm. Under neutral or alkaline pH values, P(AA-co-FA)-functionalized BNNTs are highly emissive in contrast to acidic pH conditions where the fluorescent intensity is absent or low. No increase in the absorption was observed when the suspension pH was increased from 7 to 10. The functionalized BNNTs are easily taken up by human normal prostate epithelium (PNT1A) and human prostate cancer cell lines (DU145) and are suitable for further evaluation in cellular imaging applications.
关键词： pH switching,surface modification,cellular imaging,fluorescence,boron nitride nanotubes,polymer brushes
更新于2025-09-12 10:27:22
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Photo-control of poly(N-[4-[(4-Nitrophenyl)azo]phenyl]acrylamide) brushes on graphene oxide coated silicon surface
摘要： Poly(N-[4-[(4-Nitrophenyl)azo]phenyl]acrylamide [poly(NPAPAA)] brushes were obtained via interface-mediated reversible addition–fragmentation chain transfer polymerization to design new photoresponsive surface on the graphene oxide coated silicon substrate. Switchable surface wettability was controlled successfully by these densely packed polymer brushes using light as the exterior stimulation. The relatively nonpolar trans azobenzene polymer brushes were converted to a polar cis form (with a larger dipole moment) utilizing light of the suitable wavelength. This conversion is reversible and can be switched back by employing visible light. Cis–trans photo-induced isomerization provided a reversible contact angle change (~ 9o) with UV and visible light for the poly(NPAPAA) brushes under successive irradiation cycles. This study may be promised to control cell culture surface without leaving any residual in terms of alternative medicine.
关键词： Interface-mediated RAFT polymerization,Photoresponsive polymer brushes,Switchable surface wettability
更新于2025-09-09 09:28:46