0000000000354558

AUTHOR

Christopher Barner-kowollik

0000-0002-6745-0570

showing 3 related works from this author

On the Schwarzschild Effect in 3D Two‐Photon Laser Lithography

2019

International audience; The two‐photon Schwarzschild effect in photoresists suitable for 3D laser lithography is revisited. The study ranges over seven orders of magnitude in exposure time (from 1 µs to 10 s) and investigates a wide variety of different photoresist compositions. For short exposure times (“regime I”), the laser power at the polymerization threshold can scale with the inverse square root of the exposure time, as naively to be expected for two‐photon absorption. Substantial deviations occur, however, for low photoinitiator concentrations. For intermediate exposure times (“regime II”), a Schwarzschild‐type of behavior is found, as discussed previously. For very long exposure ti…

[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph]Materials science02 engineering and technologyPhotoresist010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesTwo-photon absorptionMolecular physicsAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic Materials[SPI.MAT]Engineering Sciences [physics]/MaterialsOrders of magnitude (time)Laser power scalingDiffusion (business)[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics0210 nano-technologyAbsorption (electromagnetic radiation)Schwarzschild radiusMaskless lithography
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Wavelength-Selective Softening of Hydrogel Networks.

2021

Photoresponsive hydrogels hold key potential in advanced biomedical applications including tissue engineering, regenerative medicine, and drug delivery, as well as intricately engineered functions such as biosensing, soft robotics, and bioelectronics. Herein, the wavelength-dependent degradation of bio-orthogonal poly(ethylene glycol) hydrogels is reported, using three selective activation levels. Specifically, three chromophores are exploited, that is, ortho-nitrobenzene, dimethyl aminobenzene, and bimane, each absorbing light at different wavelengths. By examining their photochemical action plots, the wavelength-dependent reactivity of the photocleavable moieties is determined. The wavele…

Materials scienceLightCell SurvivalNanotechnologyBiocompatible MaterialsCell LinePolyethylene Glycolschemistry.chemical_compoundMiceBimaneTissue engineeringCell AdhesionAnimalsGeneral Materials ScienceNitrobenzenesBioelectronicsDrug CarriersMechanical Engineeringtechnology industry and agricultureHydrogelsChromophoreBridged Bicyclo Compounds HeterocyclicchemistryMechanics of MaterialsDrug deliverySelf-healing hydrogelsBiosensorEthylene glycolAdvanced materials (Deerfield Beach, Fla.)
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The Next 100 Years of Polymer Science

2020

International audience; The year 2020 marks the 100th anniversary of the first article on poly merization, published by Hermann Staudinger. It is Staudinger who realized that polymers consist of long chains of covalently linked building blocks. Polymers have had a tremendous impact on the society ever since this initial publication. People live in a world that is almost impossible to imagine without synthetic polymers. But what does the future hold for polymer science? In this article, the editors and advisory board of Macromolecular Chemistry and Physics reflect on this question.

chemistry.chemical_classificationPolymers and PlasticsPolymer scienceChemistryOrganic Chemistry02 engineering and technologyPolymer010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciences0104 chemical sciences[CHIM.POLY]Chemical Sciences/PolymersPolymerizationPolymer chemistryMaterials ChemistryPhysical and Theoretical Chemistry0210 nano-technology
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