Inkjet Printing of Functional Polymers and Materials: 2nd International Workshop in Eindhoven

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Controlled pattern formation of poly[2-methoxy-5-(2'-ethylhexyloxyl)-1,4-phenylenevinylene] (MEH-PPV) by ink-jet printing

A detailed survey on the processing of poly[2-methoxy-5-(2'-ethylhexyloxyl)-1,4-phenylenevinylene] (MEH-PPV) solns. via ink-jet printing and the subsequent characterization of the resulting films is reported. The printability of MEH-PPV dissolved in different solvents, and with varied concns., is studied. Limitations of the printability of highly concd. polymer solns. are overcome by using ultrasonication. The pattern formation of the resulting lines is explained in relation to the contact angle formed by the MEH-PPV soln. on the substrate and interchain interactions. A uniform thickness distribution of MEH-PPV films is obtained when toluene is used as the solvent. Further improvement on the surface quality of the lines is achieved by optimizing the printing parameters. The line stability as a function of the print-head velocity is also studied. Addnl., current-voltage (I-V) characteristics and the morphol. of the MEH-PPV films, as detd. by at. force microscopy, are discussed. [on SciFinder (R)

Ink-jet printing of polymers : from single dots to thin film libraries

Recent results on the ink-jet printing of polymer films are presented. Films that were printed using an ink-jet process based on one single solvent always suffered from ring formation, i.e. the coffee-drop effect. This drawback could be overcome by the use of solvent mixtures. The effects of solvent mass ratio, print head velocity, dot spacing and printing method were investigated and optimized to reproducibly obtain homogeneous polymer films (6 6 6 mm size). The results obtained represent an important step towards the application of ink-jet printing for the controlled deposition of polymer dots and libraries

Combinatorial and high-throughput polymer research : composition of complete workflows

Completion of the combinatorial polymer research workflow requires an extra sample prepn. step in the case a solid sample is required for characterization. Discretely prepd. sample libraries rather than continuous gradients offer the advantage of compatibility with existing workflows and well-defined compns. We demonstrate the feasibility of ink-jet printing for the prepn. of such polymer libraries. Our ink-jet printer uses micropipettes to aspirate a polymer soln. from a microtiterplate and print it on a substrate. 2% wt. polystyrene solns. could easily be printed, using a variety of solvents. However, printability of a polymer soln. decreases with mol. wt. and concn., partially due to elasticity effects. A polymer film could be created by printing an array of droplets such that they merge on the surface and leave a film after dryin

Inkjet printing as a deposition and patterning tool for polymers and inorganic particles

Inkjet printing is an attractive patterning technology, which has become increasingly accepted for a variety of industrial and scientific applications. This review primarily presents an overview of the investigations that have been conducted since 2003 into inkjet-printing polymers or metal-containing inks and mentions related activities. The first section discusses the droplet-formation process in piezoelectric drop-on-demand printheads and the physical properties that affect droplet formation and the resolution of inkjet-printed features. The second section deals with the issues that arise from printing polymers, such as printability and the output characteristics of devices made by this route. Finally, the challenges and achievements attached to inkjet printing metal-containing inks are discussed before concluding with a few remarks about the future of the field. This journal is © The Royal Society of Chemistr

Light-emitting iridium(III) and ruthenium(II) polypyridyl complexes containing quadruple hydrogen-bonding moieties

A novel compound containing both a 2,2-bipyridine as well as a 2-ureido-4[1H]-ureidopyrimidinone supramolecular moiety ( 3) has been synthesised and fully characterized by 1H-NMR, MALDI-TOFMS, UV-vis and IR spectroscopy. Subsequent coordination to iridium and ruthenium polypyridyl precursors allowed the formation of iridium(III) and ruthenium(II) polypyridyl dimers ( 5 and 7) assembled via quadruple hydrogen-bonding as well as metal coordination interactions. The syntheses and complete characterization of these materials by means of two-dimensional NMR techniques (1H–1H COSY and 1H–1H DOSY) as well as IR and MALDI-TOFMS are described in detail. Comparative studies of the optical properties of the luminescent model complexes ( 5 and 7) and the dimer species ( 5 and 7) are also illustrated. In addition, good processability of the materials has been demonstrated by inkjet printing leading to thin films revealing their potential for light-emitting devices

Ink-jet printing polymers and polymer libraries using micropipettes

A study is presented on ink-jet printing polymers, aiming at library generation for combinatorial material science applications, using (optimized) micropipettes. Solvents were successfully ink-jet printed, up to 160 mPa s viscosity. Printability of polymer solutions decreases strongly with and polymer concentration, due to elastic stresses originating from elongational flow in the pipette nozzle. The feasibility of ink-jet printing to generate arrays of polymer dots and films was demonstrated

Film thickness dependency of the emission colors of PPE-PPVs in inkjet printed libraries

The influence of side chains, film thickness, and thermal treatment of .pi.-conjugated polymers on emission colors, was studied. The resp. thickness libraries of six alkoxy-substituted poly(p-phenylene ethynylene)-alt-poly(p-phenylene vinylene)s (PPE-PPVs) were prepd. by inkjet printing. The optical properties of the printed libraries were screened utilizing high-throughput methods. The emission colors of the studied polymers strongly depend on the inter-chain interactions which are increased with increasing film thickness and influenced by the side chains. Upon annealing at 70, white emission was obsd. from the printed films

Ink-jet printing of luminescent ruthenium- and iridium-containing polymers for applications in light-emitting devices

Defined films of luminescent ruthenium(II) polypyridyl-poly(methyl methacrylate) (PMMA) and iridium(III) polypyridyl-polystyrene (PS) copolymers could be prepared by ink-jet printing. The copolymers were deposited on photoresist-patterned glass substrates. Films as thin as 120 nm could be printed with a roughness of 1 to 2%. In addition, the film thickness could be varied in a controlled way through the number of droplets deposited per unit area. The topography of the ink-jet printed films was analyzed utilizing an optical profilometer. The absorbance and emission spectra were measured using fast parallel UV-vis and fluorescence plate reader