Thin Ink Research Articles

Surface Modification and Properties of Thin Ink Films with Added TiO2 and ZnO Nanoparticles Applied on Paperboard Substrates.

In this study, the surface modification of thin ink films with added nanoparticles was used to improve the functional properties of ink applied on paperboard substrates. The surface modification was performed by additional exposure of the samples to xenon radiation. Anatase TiO2, rutile TiO2 and ZnO were added to the base ink. The effect of surface modification on the surface, structural, and mechanical properties of the printed ink films was determined by FTIR-ATR spectroscopy, calculating the surface free energy and adhesion parameters, performing the rub resistance test of the printed samples, and by measuring the resistance to bending. Color measurements on the ink films were performed in order to observe the optical properties of unmodified and modified samples. The results showed that surface modification significantly improved the adhesion properties of the thin ink films and the mechanical properties of the samples. The results obtained on uncoated and coated paperboard showed that the addition of rutile TiO2 and ZnO nanoparticles had the greatest effect on the rub resistance of the ink films. The results of the color analysis showed that the addition of nanoparticles did not change the optical properties of the modified ink films and that rutile TiO2 and ZnO nanoparticles improved the lightfastness of the applied ink films.

Infrared Laser Ablation Microsampling with a Reflective Objective.

A Schwarzschild reflective objective with a numerical aperture of 0.3 and working distance of 10 cm was used for laser ablation sampling of tissue for off-line mass spectrometry. The objective focused the laser to a diameter of 5 μm and produced 10 μm ablation spots on thin ink films and tissue sections. Rat brain tissue sections 50 μm thick were ablated in transmission geometry, and the ablated material was captured in a microcentrifuge tube containing solvent. Proteins from ablated tissue sections were quantified with a Bradford assay, which indicated that approximately 300 ng of protein was captured from a 1 mm2 area of ablated tissue. Areas of tissue ranging from 0.01 to 1 mm2 were ablated and captured for bottom-up proteomics. Proteins were extracted from the captured tissue and digested for liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis for peptide and protein identification.

Effect of UV-Curable Inkjet Printing Parameters on Physical, Low-Stress Mechanical, and Aesthetic Properties of Polypropylene Knitted Fabrics

As the use of textile polypropylene (PP) fibers becomes more common in commercial textiles and sportswear, the investigation of the effects of UV-curable ink on the heat-sensitive PP knitted fabrics is crucial to optimize functional clothing design. This study investigated the effects of UV-curable ink on the heat-sensitive PP knitted fabrics when the ink was cured using UV light at room temperature, to avoid degradation of the PP fabric by high temperature, and provided an alternative coloring method for PP fabric used in sportswear. The influences of printing parameters such as the printing distance, number of overprints, and color of ink on fabrics as well as aesthetic, physical, and low-stress mechanical properties in terms of tensile, bending, shearing, surface, and compression were systematically investigated. The results indicated that the physical properties and low-stress mechanical properties of PP fabrics printed with UV-curable ink were significantly affected by the number of overprints and the color of the prints, whereas the color appearance was affected mainly by the number of overprints and the printing distance. In terms of the fabric’s hand value, only 2HB and 2HG5 were significantly affected by the number of overprints and the color of the prints, with the prediction rate exceeding 40 % among the low-stress mechanical properties. The fabric’s hand value was not significantly affected by the thin UV-cured ink film when compared with the fabric itself. Fabric printed in a color with the greatest lightness and the fewest overprints had the lowest fabric weight, thickness, and color difference (ΔE) towards the reference color, in addition to better bending recovery and resilience properties. The new knowledge from this study can provide an alternative coloring method for PP knitted fabric to increase the design variety available to textile designers who use PP fabric. The results from this study contribute to the textile and knitwear design industry.

Coarse-Grained Molecular Dynamics Simulation of Perfluorosulfonic Acid Dispersion in Mixtures of Water and Ethanol

Coarse-grained molecular dynamics simulation was used to investigate the aggregation behavior of perfluorosulfonic acid (PFSA) ionomers with equivalent weight (EW) of 844 in the dilute mixed water and ethanol solutions. Four different chain lengths (10, 20, 60, and 200 repeat units) of PFSA were studies. It was found that the shorter (10 and 20 repeat units) ionomers form spherical aggregates, whereas the longer (60 and 200 repeat units) ones form cylindrical-like aggregates in pure water and in the mixed water/ethanol solvents at ethanol contents ≤ 50 wt%. The aggregated structures become loose when ethanol content is increased to 50 wt%. With further increasing the ethanol content, the PFSA ionomers gradually uncoil their aggregated structures and extend the chains in the solution. The variation of aggregate structure with the ethanol content was consistent with our experimental observation. The finding will be useful for designing ionomer dispersed solution for thin film and catalyst ink fabrication.Figure caption: EW844 PFSA polymers form cylindrical-like aggregates a low ethanol contents and random coil conformations at high ethanol contents. Figure 1

ANALYSIS OF EVAPORATIVE DRYING OF THIN INK FILMS USING HIGH-VELOCITY HOT-AIR IMPINGING JETS: A COMPREHENSIVE REVIEW

Hot impinging air jets are usually used to increase heat and mass transfer. The dehydration of materials is a procedure of common significance in the chemical processes, forensic science and food industries; in the fabrication of paper, plastics and textiles as well. Effective drying of thin ink films is becoming progressively significant in the quickly development printing, packaging and coating industries. In order to minimize capital and operating cost, variables need to be optimized. For both researchers and commercial dryers, an optimization of the nozzles under striking air jets is offered for ink drying. To supply information to industrial users, a comprehensive literature review was presented to the research. An outline of the previous work of impinging air jets is also given.

An investigation into evaporative ink drying process on forced convective heat and mass transfer under impinging air jets

Impinging air jets are widely used in industry for drying, cooling and heating due to high heat and mass transfer coefficients which are developed in the impingement region. High velocity heated air impinging jets have proved to be very effective to enhance evaporative ink drying especially on the rotary presses for the packaging and converting industry. In this paper, to provide data for ink dryer designers, an investigation has been carried out to obtain the heat and mass transfer coefficients which constitute the evaporative drying of thin ink films. Finally, the theoretical results are compared for the constant rate period and falling rate period with some experimental and theoretical results found to be satisfactory particularly for the drying time.

Reading magnetic ink patterns with magnetoresistive sensors

Information storage and monitoring relies on sensitive transducers with high robustness and reliability. This paper shows a methodology enabling the qualification of magnetic sensors for magnetic pattern readout, in applications different than hard disk magnetic recording. A magnetic tunnel junction MTJ sensor was incorporated in a reader setup for recognition of the magnetization of patterned arrays made of CoCrPt thin films and magnetic ink. The geometry of the sensor (in particular, the footprint and vertical distance to the media) was evaluated for two sensor configurations. The readout conditions were optimized to cope for variable media field intensity, resulting from CoCrPt film or magnetic ink thickness, with fixed reading distance and dimensions of the pattern. The calibration of the ink magnetic signal could be inferred from the analytical calculations carried out to validate the CoCrPt results.

Photoacoustic imaging methodology for the optical characterization of contact lenses

We demonstrate photoacoustic microscopy as a metrology method for the optical characterization and quality control of contact lenses (CLs). Dual-wavelength excitation is applied to CLs tinted on both sides with two thin ink layers, each of them possessing distinctly different optical absorption properties. Thus, the method is capable of measuring the elevation maps of both CL surfaces during two subsequent imaging sessions and extracting the CL thickness, curvatures, and dioptric power. We show that such an easily implementable technique provides robust, high-precision, cost-effective three-dimensional imaging and characterization of both rigid and soft CLs, which renders it highly favorable for a broad range of applications.

An Accurate Method for Measuring the Sheet Impedance of Thin Conductive Films at Microwave and Millimeter-Wave Frequencies

A simple and accurate method to measure the complex sheet impedance of thin conductive films on dielectric substrates is reported. This method allows for accurate extraction of the sheet impedance without characterizing the substrate (thickness and permittivity) beforehand, within a wide range of frequencies and sheet complex impedances. In this method, the sample is placed between two rectangular waveguide flanges, creating a discontinuity. The discontinuity is modeled by an equivalent $\Pi $ -circuit, and the sheet impedance is found from measured circuit parameters of the sample and bare substrate. We propose two retrieval approaches using different circuit parameters, examine their extraction accuracy with various substrate thicknesses and sheet impedances, and determine the most reliable extraction method. Uncertainty analysis under random perturbations of measured scattering parameters is also performed to investigate the robustness of the technique. Experimental studies are carried out to demonstrate the validity of the proposed approach for the impedance measurements of thin conductive ink films supported by both thin or thick (up to 0.28 times the wavelength in the dielectric) substrates.

Which elements are useful for understanding the composition of ancient papyrus inks?

X-ray fluorescence spectrometry was used in mapping and spot analysis modes, to help identify which elements are useful for understanding the composition of ancient papyrus inks, for 25 papyri from four age groups. We report seven elements (Al, Si, P, S, Ca, Ti, Fe) which provide sufficient contrast to be useful for mapping analysis, and 16 elements (P, S, Cl, K, Ca, V, Mn, Ni, Cu, Zn, Rb, Sr, Nb, Ag, Ba, and Pb) which show significant differences through time. Only one element – Pb – showed sufficient contrast in the thin ink layer to be significantly different when measured on the ink and adjacent papyrus. There is greater complexity in the elemental compositions of the papyrus and ink than can be understood with a study this size and additional work is required to develop and explain the patterns observed here.

Simultaneous Real-Time Analysis of Bulk and Bottom Cure of Ultraviolet-Curable Inks Using Fourier Transform Infrared Spectroscopy.

The curing characteristics of an ultraviolet (UV) ink layer are of utmost importance for the development of UV inks. Measuring either bulk or bottom cure in itself is not new and has been the subject of many articles. In this article, two methods are described based on Fourier transform infrared (FT-IR) spectrometry to measure in real time and simultaneously the bulk and bottom cure of a thin UV ink layer. The procedure consists of applying a thin (10-12 µm) layer of UV-curing ink on an attenuated total reflection (ATR) crystal. The bottom cure is measured with ATR. The bulk cure is measured simultaneously with a reflection analysis (method 1) or a transmission analysis (method 2). With both methods, the bulk and bottom cure can be determined. To overcome problems with the interference in the ATR reflection setup, it is recommended to use the ATR transmission setup.

Inkjet Printed Wire-Grid Polarizers for the THz Frequency Range

We have investigated the use of inkjet printing technology for the production of THz range wire-grid polarizers using time-domain terahertz spectroscopy (TDTS). Such technology affords an inexpensive and reproducible way of quickly manufacturing THz range metamaterial structures. As a proof-of-concept demonstration, numerous thin silver-nanoparticle ink lines were printed using a Dimatix DMP-2831 printer. We investigated the optimal printing geometry of the polarizers by examining a number of samples with printed wires of varying thickness and spacing. We also investigated the polarization properties of multiply-stacked polarizers.

Highly Active and Durable Extended Surface Oxygen Reduction Electrocatalysts

The amount of platinum (Pt) in the catalyst layer accounts for a significant portion of fuel cell cost and limits the commercial deployment of proton exchange membrane fuel cells.[1] Catalyst studies typically focus on the oxygen reduction reaction (ORR), since the reaction is orders of magnitude slower kinetically than hydrogen oxidation. Extended surface nanomaterials offer key advantages in ORR, including an order of magnitude higher site-specific activity, long range conductivity, and long term durability.[2] Traditionally, however, the catalyst type has been limited by low surface areas. Spontaneous galvanic displacement occurs when a more noble metal cation contacts a less noble metal template, and combines aspects of corrosion and electrodeposition. In ORR, catalysts formed by spontaneous galvanic displacement are ideally situated, taking advantage of the specific activities generally associated with the catalyst type while significantly improving upon their surface area.[3] Galvanic displacement has been used to deposit small amounts of Pt onto extended templates, and in the case of Pt-nickel (Ni) nanowires, has produced materials with surface areas in excess of 90 m2 gPt ‒1.[4] Post-synthesis processing has been used to improve the activity and durability of Pt-Ni nanowires in rotating disk electrode (RDE) half-cells. Thermal annealing integrated Pt-rich and Ni-rich zones, compressing the Pt lattice and improving ORR activity.[5] Acid leaching and oxidation of the Pt-Ni nanowires also removed surface Ni and formed Ni oxides near the nanowire surface, improving catalyst durability and reducing Ni dissolution in durability tests (30,000 cycles, 0.6‒1.0 V). Recently, Pt-Ni nanowires were studied for their ORR activity in RDE half-cells using updated testing protocols. A rotational air drying method formed thin, uniform coatings onto the RDE working electrodes.[6] Thin catalyst ink dispersions also allowed for the ORR diffusion-limited current to be reached while maintaining a low Pt loading. Using these methods improved Pt-Ni nanowire activity in RDE half-cells by 60%. The optimized Pt-Ni nanowires produced an ORR mass activity 9 times greater than Pt/HSC, while losing less than 3% of that activity and less than 0.5% catalyst mass to dissolution in durability testing. Atomic layer deposition (ALD) has also been used in an effort to replicate the Pt-Ni nanowire synthesis by galvanic displacement. Works has included different chemistries (oxygen and hydrogen routes), as well as efforts to disperse the nanowire template without the benefit of a liquid medium. Successful use of ALD can potentially produce catalysts on a much larger, more commercially viable, scale. Figure 1. Surface areas (x-axis) and site-specific oxygen reduction activities at 0.95 V (y-axis) of Pt/HSC and Pt-Ni nanowires, as-synthesized and modified by post-synthesis processing. The solid black line denote constant mass activities of 100, 400, and 800 mA mgPt ‒ 1. [1] D. Papageorgopoulos, in: U.S. Department of Energy (Ed.), http://www.hydrogen.energy.gov/pdfs/review14/fc000_papageorgopoulos_2014_o.pdf, 2014. [2] M. Debe, in: U.S. Department of Energy (Ed.), http://www.hydrogen.energy.gov/pdfs/review09/fc_17_debe.pdf, 2009. [3] S.M. Alia, Y.S. Yan, B.S. Pivovar, Catalysis Science & Technology, 4 (2014) 3589-3600. [4] S.M. Alia, B.A. Larsen, S. Pylypenko, D.A. Cullen, D.R. Diercks, K.C. Neyerlin, S.S. Kocha, B.S. Pivovar, ACS Catalysis, 4 (2014) 1114-1119. [5] B. Pivovar, Extended, Continuous Pt Nanostructures in Thick, Dispersed Electrodes, in: U.S. Department of Energy (Ed.), http://www.hydrogen.energy.gov/pdfs/review14/fc007_pivovar_2014_o.pdf, 2014. [6] K. Shinozaki, J.W. Zack, R.M. Richards, B.S. Pivovar, S.S. Kocha, Journal of The Electrochemical Society, 162 (2015) F1144-F1158. Figure 1

Mechanism of reverse-offset printing

We propose a mechanism for reverse-offset printing based on a mathematical model. In reverse-offset printing, high resolution is achieved by patterning a coated, thin ink film with an intaglio-patterned cliché. By using the relationships among the ink blanket adhesion strength, the ink cliché adhesion strength, and the ink cohesion strength, a criterion for successful patterning is derived. We found that there is a printing window in the ink blanket adhesion strength that depends on the shear strength of the ink film and the dimensions of the pattern. The printing window diminishes as the line width decreases, resulting in a minimum printable line width. The proposed mechanism was verified by printing patterns with various shapes and dimensions.

Method for Testing and Analyzing the Printing Performance of Fluorescent Inks

In recent years, fluorescent ink, with a unique color performance and the advantages of green non-toxic, fast drying, thin ink, etc., is widely used in packaging printing, security printing, and other fields. What’s more, the luminescent properties and the interaction with paper of fluorescent ink are pained more and more attention. In this experiment, an ultraviolet light source is used to motivate the samples to emit, the fiber spectrophotometer is used to receive the reflected light of the samples in the vertical direction of the samples. The tone rendering curve and dot gain curve are obtained according to the radiation energy data of the sample, the printing indicators of fluorescent ink are obtained by analyzing the reproducing image tone scale and dot expansion characteristics of ink on the paper.

Dyaspora All Up in the Mix: Jean-Ulrick Desert, Mapping Fragmented Archaeologies

Jean-Ulrick Desert’s artwork explores diasporic black postmodernity. A Berlinbased artist who has lived in the United States, Europe, and Haiti, Desert produces evocative and enigmatic work about the black diasporic experience. Participating in a visual lexicon that decodes the inevitability of fragmentation, Desert liberates himself from the constraints of working in any one medium or style. Using diverse artistic media, including drawing, sculpture, photography, performance, and installation, he creates multidimensional spaces shaped by his formal education in architecture and his years as an exhibition designer. Personally coded narratives are intertwined with contemporary Western art practices rendered in provocative ways. Subtle strategies of pastiche anchor his earlier artworks and challenge the hackneyed nature of so-called identity politics. His recent use of self-presentation participates in the visual language of camp and sartorial play, incorporating elements that dare as well as elements that reveal truth. His satirical performance “actions,” photographs, multimedia installations, and ephemera ingeniously challenge notions of racial visibility and cultural authenticity. Desert’s “self-portrait” drawing series, L’ABCdaire de ma vie privee (The ABC’s of My Private Life) (2005), creates opportunities for the evocative exploration of race, cultural identity, belonging, and memory (see Color Plate 1). Images culled from his personal photo albums combine with simple letters and unassuming words in French, Kreyol, German, and English on fine paper lined with precisely spaced thin pencil and ink strokes that mimic the penmanship notebook pages he used as a child while living in Haiti. The plate for the letter B places us in Brooklyn, the mecca for Haitians. It is during this first part of his transnational migration that Desert realizes that he has become black and foreign; his frenchyness makes him exotic and othered. He does not feel oppressed; rather, he feels bewildered by these racial and national labels. While the images are embedded within the cultural specificity of the Haitian dyaspora, they resonate with the

Use of Total Internal Reflection Raman (TIR) and Attenuated Total Reflection Infrared (ATR-IR) Spectroscopy to Analyze Component Separation in Thin Offset Ink Films after Setting on Coated Paper Surfaces

The interactive behavior of ink constituents with porous substrates during and after the offset print process has an important effect on the quality of printed products. To help elucidate the distribution of ink components between the retained ink layer and the substrate, a variety of spectroscopic and microscopic analysis techniques have been developed. This paper describes for the first time the use of total internal reflection (TIR) Raman spectroscopy to analyze the penetration behavior of separated offset ink components (linseed oil, solid color pigment) in coated papers providing chemically intrinsic information rapidly, nondestructively, and with minimal sample preparation. In addition, the already widely applied technique of attenuated total reflection infrared spectroscopy (ATR-IR) was evaluated in parallel and compared. The results of the ATR-IR Raman clearly revealed an improvement in uppermost depth resolution compared with values previously published from other nondestructive techniques, and the method is shown to be capable of providing new knowledge of the setting of thin (0.25-2 μm) offset ink films, allowing the spreading and the penetration behavior on physically different paper coating surfaces to be studied.

Surface Impedance Measurement of Resistive Coatings at Microwave Frequencies

A simple approach to estimate the surface impedance of a thin ink deposition on dielectric substrates is described. The measured sample is transversally accommodated in a waveguide, and the scattering parameters are measured. Then, the surface impedance value is recovered by recurring to an efficient transmission-line approach. Closed-form relations are proposed, which allow removing the dispersive effect of the substrate on the estimated surface impedance. The robustness of the retrieving procedure is analyzed, showing that the one based on the transmission coefficient provides more accurate results than the reflection-based one. The positioning of the sample is also investigated, highlighting that the placement inside the waveguide leads to incorrect estimations of the surface impedance with fictitious high imaginary parts because of the presence of air gaps between the sample and the waveguide walls, which transform the uniform layer to a capacitive resistive frequency selective surface. A modified setup with a uniform resistive ink deposition pressed between the waveguide flanges is therefore adopted. Additional experimental results on the effect of the dielectric substrate and on the homogeneity of the ink deposition are reported.

Arita Hachiro and the Conclusion of the Anti-Comintern Pact: A Case Study in “Thin Ink” Diplomacy Japanese Diplomacy in the 1930's-Four Foreign Ministers-

Arita Hachiro and the Conclusion of the Anti-Comintern Pact: A Case Study in “Thin Ink” Diplomacy Japanese Diplomacy in the 1930's-Four Foreign Ministers-

The Effect of Conductive Ink Layer Thickness on the Functioning of Printed UHF RFID Antennas

In this study, the effect of the conductive ink layer thickness on the performance of printed ultra-high-frequency (UHF) radio-frequency identification (RFID) tag antennas was investigated. A simple quarter wave dipole tag for European UHF RFID frequencies was designed to be tested in this study. All the tags were made by using screen-printing technique. Three different thicknesses for the ink layer were used. Performance of the tags was analyzed by the measurement of threshold and backscatter power. The results show that it is possible to produce RFID tag antennas by screen printing and it is possible to optimize the tag performance by adjusting the thickness of the electrically conductive layer. The results show how the performance characteristics deteriorated when the thickness of the printed ink layer was reduced. However, it was also shown that thin ink layers can be used in some applications and cost savings can be achieved in this way. It is therefore important to recognize these effects on the performance.