Inkjet Printing Of Inks Research Articles

The effects of coil–stretch transition behavior of polyfluorene inks on single droplet formation during inkjet printing

For drop-on-demand (DOD) inkjet printing, stable and single ink droplet formation without satellite dots is the key to improve the print quality. The formation of stable and single droplet is influenced by filament break up and the polymer chain’s coil–stretch transition behavior. In this paper, the droplet formation behaviors of polyfluorene (PFO) ink at various driving voltages (V), polymer chain’s coil–stretch transition mechanism and its effects on single ink droplet formation are investigated. It indicates that when 58 <V ≤ 63 V, a single and stable droplet is formed with a pulse time of 38.5 μs. At this stage, the Weissenberg number (Wi) < 0.5, the PFO molecular chain is coiled to guarantee stable and single droplets. When V > 63 V, Wi > 0.5, the PFO molecular chain is stretched because of the high hydrodynamic forces, resulting unwanted satellite droplets. When 55 <V ≤ 58 V, the droplet shrinks into the nozzle, which indicates that the kinetic energy supplied by the deformation of the piezoelectric transducer isn't enough to force the droplet to be jetted from the nozzle.

Preparation of highly dispersible glass frit powders and its application in ink-jet printing ink

The dispersion of low surface polarity ultra-fine powders has been a technical bottle-neck in many industrial applications, including ceramic or glass decoration and solar electrodes. Herein, we report a surface modification method to improve the adsorption strength between the ultra-fine (300 nm) powder and dispersant by coating a layer of mesoporous silica on the surface of a glass frit. The modified ultra-fine glass frit shows a high density of polar surface functional groups which can increase the adsorption amount and strength between the modified powder and the dispersant, as confirmed by the adsorption experiment and IR analysis. The modified powder also was used to prepare ceramic ink which can be completely filtered under a 1 μm sized pores filter, thus satisfying the requirement of industrial ink-jet printing.

Test-System for Bacteria Sensing Based on Peroxidase-Like Activity of Inkjet-Printed Magnetite Nanoparticles.

Rapid detection of bacterial contamination is an essential task in numerous medical and technical processes and one of the most rapidly developing areas of nano-based analytics. Here, we present a simple-to-use and special-equipment-free test-system for bacteria detection based on magnetite nanoparticle arrays. The system is based on peroxide oxidation of chromogenic substrate catalyzed by magnetite nanoparticles, and the process undergoes computer-aided visual analysis. The nanoparticles used had a pristine surface free of adsorbed molecules and demonstrated high catalytic activities up to 6585 U/mg. The catalytic process showed the Michaelis–Menten kinetic with Km valued 1.22 mmol/L and Vmax of 4.39 µmol/s. The nanoparticles synthesized were used for the creation of inkjet printing inks and the design of sensor arrays by soft lithography. The printed sensors require no special equipment for data reading and showed a linear response for the detection of model bacteria in the range of 104–108 colony-forming units (CFU) per milliliter with the detection limit of 3.2 × 103 CFU/mL.

Development and design of low volatile waterborne disperse ink using LF-NMR

The water retention of printing inks is of the utmost importance. According to low -field nuclear magnetic resonance (LF-NMR) to detect the behavior of polyols and water, polyols with excellent water retention performance can be selected quickly. The water retention of disperse ink is closely related to the intramolecular/intermolecular forces of each component in the disperse ink. The relationship between each component of the ink is revealed by LF-NMR. The water retention of ink was also evaluated by LF-NMR. Therefore, the LF-NMR was able to design ink formulation and evaluate ink quality. Compared with NNO and TD-1109, Surfynol CT-136 had a higher grinding efficiency for disperse dyes. The physicochemical properties of disperse ink was evaluated to meet the requirements of inkjet printing ink. The rheological properties of the disperse inks were characterized by rotary rheometer, which were confirmed as Newtonian fluid; The quality of the ink-jet printing pattern is closely related to the ink jet performance. The formation process of the ink droplet and the parameters of the ink droplets were observed by the ink droplet observer. The ink has excellent jetting properties and a high-quality print pattern at an appropriate viscosity (3.1 mPa.s) and surface tension (34.2 mN/m). The excellent affinity between NVP/VA copolymer (NVP/VA64) and disperse dyes was confirmed by ultraviolet spectrophotometer (UV spectrophotometer). The scanning electron microscope (SEM) images of printed fabrics show that there is a film on the surface. The NVP/VA copolymer can be used as a carrier for disperse dye to improve the fixation and fastness of disperse dye in polyester fabrics.

Characterization of AuNPs based ink for inkjet printing of low cost paper based sensors

The functionality of an effective metal NPs based ink in inkjet printing depends on its ability to achieve high mass concentration as well as suitable rheological properties for stable printability. In this work, AuNPs synthesized by USP were successfully formulated in inks of varying [Au] using PVP40 as stabilizer and DI water as solvent. The influence of the increasing [Au] on the rheological, flow and wetting behavior were investigated for requisite printable characteristics. Thermo-physical characterization was carried out on the optimized concentrated AuNPs ink using TGA, DLS, SEM and EDX techniques.

Formulation of a graft polymer-containing aqueous yellow ceramic ink for digital ink-jet printing.

We herein reported the preparation of an eco-friendly aqueous yellow ceramic ink and subsequent examination of its printability for ink-jet printing applications. For this purpose, a water based ceramic ink was formulated using ceramic pigments to give a clear color during high-temperature heat treatment (>1000 °C), ultimately yielding an ink suitable for application in ceramic tile decoration. To improve the low dispersion stability of the aqueous ceramic ink compared to that of a conventional organic solvent-based ceramic ink, the pigment particles were dispersed using a graft polymer. More specifically, this graft polymer was composed of polyacrylic acid as the main chain to provide electrostatic repulsion and grafted poly(ethylene glycol) methyl ether methacrylate as the side chain to provide steric hindrance. Furthermore, additive-induced foaming issues were significantly reduced through the use of this graft polymer as a surfactant. The effects of the rheological properties of the prepared ceramic ink and the subsequent operation conditions of the piezoelectric print head were then investigated in detail to optimize the ink jettability and printability.

Preparation of low-temperature sintered high conductivity inks based on nanosilver self-assembled on surface of graphene

Finer nanoplates of silver are prepared by self-assembly on the surface of graphene, and the low-temperature sintered high conductivity ink containing the silver nanoplates is prepared. Most importantly, graphene is added to the solution before the chemical reduction reaction occurs. Firstly, it is found that silver nanoplates have self-assembly phenomenon on the surface of graphene. Secondly, the Ag nano hexagonal platelets (AgNHPs) with small particle sizes (10 nm), narrow distribution and good dispersion are prepared. Especially, smaller sizes (10 nm) and narrower particle size distribution of AgNHPs particles can be easily controlled by using this process. Finally, the conductivity of the ink is excellent. For example, when the printed patterns were sintering at 150 °C, the resistivity of the ink(GE: 0.15 g/L) reached the minimum value of 2.2×10−6 Ω·cm. And the resistivity value was 3.7×10−6 Qcm, when it was sintered at 100 °C for 30 min. The conductive ink prepared can be used for the field of printing electronics as ink-jet printing ink.

Controlling the micro-structure of disperse water-based inks for ink-jet printing

The study aims to investigate the effect of additives (poly (vinyl pyrrolidone) PVP, glycerol, ethylene glycol) on the performances of disperse water-based inks for ink-jet printing and how such additives interact with water. This should help into design suitable inks for textile printing by ink-jet printing, in particular for synthetic fibers such as polyester fabrics. Thirteen kinds of inks were prepared, and the glycerol content was replaced by water and PVP (K15, K30, K60), and the solubility parameter of the additive was calculated by the group contribution method. Low field nuclear magnetic resonance (LF-NMR) reveals the existence of bound water, intra-microstructure water, and extra-microstructure water in the ink, and the intra-microstructure water is entrapped inside the micro-structure formed by additives, mainly due to the presence of PVP. The optimal ink (Y5K30) has a low linewidth relative change (0.4%) and excellent sharpness. The reason is the existence of microstructure in ink, which reduces the mobility of solvent in ink and the diffusion of ink on fabric. PVP and disperse dyes have a strong affinity and help to improve the color depth and color fastness of the fabric.

Switchable organoplatinum metallacycles with high quantum yields and tunable fluorescence wavelengths

The preparation of fluorescent discrete supramolecular coordination complexes (SCCs) has attracted considerable attention within the fields of supramolecular chemistry, materials science, and biological sciences. However, many challenges remain. For instance, fluorescence quenching often occurs due to the heavy-atom effect arising from the Pt(II)-based building block in Pt-based SCCs. Moreover, relatively few methods exist for tuning of the emission wavelength of discrete SCCs. Thus, it is still challenging to construct discrete SCCs with high fluorescence quantum yields and tunable fluorescence wavelengths. Here we report nine organoplatinum fluorescent metallacycles that exhibit high fluorescence quantum yields and tunable fluorescence wavelengths through simple regulation of their photoinduced electron transfer (PET) and intramolecular charge transfer (ICT) properties. Moreover, 3D fluorescent films and fluorescent inks for inkjet printing were fabricated using these metallacycles. This work provides a strategy to solve the fluorescence quenching problem arising from the heavy-atom effect of Pt(II), and offers an alternative approach to tune the emission wavelengths of discrete SCCs in the same solvent.

Determination of Deposition Order of Toners, Inkjet Inks, and Blue Ballpoint Pen Combining MeV-Secondary Ion Mass Spectrometry and Particle Induced X-ray Emission.

Determination of the deposition order of different writing tools is very important for the forensic investigation of questioned documents. Here we present a novel application of two ion beam analysis (IBA) techniques: secondary ion mass spectrometry using MeV ions (MeV-SIMS) and particle induced X-ray emission (PIXE) to determine the deposition order of intersecting lines made of ballpoint pen ink, inkjet printer ink, and laser printer toners. MeV-SIMS is an emerging mass spectrometry technique where incident heavy MeV ions are used to desorb secondary molecular ions from the uppermost layers of an organic sample. In contrast, PIXE provides information about sample elemental composition through characteristic X-ray spectra coming from greater depth. In the case of PIXE, the information depth depends on incident ion energy, sample matrix and self-absorption of X-rays on the way out from the sample to the X-ray detector. The measurements were carried out using a heavy ion microprobe at the Ruđer Bošković Institute. Principal component analysis (PCA) was employed for image processing of the data. We will demonstrate that MeV-SIMS alone was successful to determine the deposition order of all intersections not involving inkjet printer ink. The fact that PIXE yields information from deeper layers was crucial to resolve cases where inkjet printer ink was included due to its adherence and penetration properties. This is the first time the different information depths of PIXE and MeV-SIMS have been exploited for a practical application. The use of both techniques, MeV-SIMS and PIXE, allowed the correct determination of deposition order for four out of six pairs of samples.

Water-based and inkjet printable inks made by electrochemically exfoliated graphene

Inkjet printable graphene inks are very attractive for applications in flexible and foldable electronics, such as wearable electronics and the Internet of Things. However, the ink preparation is still very time consuming as high concentrations can be achieved only with prolonged sonication (>24 h) or with expensive setups. Here we demonstrate a water-based inkjet printable ink made from electrochemically exfoliated graphene. A printable and stable (>1 month) ink with concentration of ∼2.25 mg mL−1 was formulated in less than 5 h, using two successive steps: first exfoliation and dispersion of large graphene flakes (>5 μm) followed by 1 h tip-sonication to reduce the flake size below 1 μm, as required for the material to be ejected by the nozzle. The formulated ink contains more than 75% single- and few-layers (i.e. less than 2 nm in thickness) graphene flakes with an average lateral size of 740 nm. Thermal annealing allows to achieve high C/O ratio (>10), which translates into one of the highest electrical conductivity (≈3.91 × 104 S m−1) reported so far for solution-processed graphene, without the use of any harsh chemical processing.

Photoinitiator‐free photopolymerization of acrylate‐bismaleimide mixtures and their application for inkjet printing

ABSTRACTThere is growing interest in using photoinitiator‐free systems in coating applications such as inkjet‐printing, because residual photoinitiator can alter the properties of the resulting polymer. Bismaleimides (BMI) offer the opportunity to polymerize acrylates without the addition of photoinitiators, as this class of molecules can serve both as polymerizable monomer and as photoinitiator together with electron donor systems, like vinyl ether monomers or acrylates. The UV‐induced copolymerization of a low‐molecular‐weight BMI with various acrylate monomers and oligomers without any photoinitiator was characterized. The BMI‐acrylate systems show comparable polymerization speeds to widely used acrylic systems with photoinitiator. Superior thermal stability as well as thermomechanical properties are achieved by enhancing acrylics with BMI. Such photoinitiator‐free systems lend themselves to be used for low‐migration coatings as well as for high‐temperature applications. Here, a characterization of selected BMI‐acrylate mixtures regarding their photocuring kinetics and their application as inks for inkjet printing is shown. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47789.

Preparation of disperse inks for direct inkjet printing of non-pretreated polyester fabrics.

The preparation of disperse inks for direct inkjet printing was carried out using disperse dye, dispersant (TD-1109, hydrophilic polyacrylic acid block copolymer), wetting agent (diethylene glycol and ethylene glycol), water-based polymers (polyvinyl alcohol (PVA) or waterborne polyester), deionized water, etc. The suitability of disperse inks for polyester fabrics was assessed via measurement of conductivity, pH, particle size surface tension and viscosity. The theological behavior of disperse inks was evaluated by rotational viscometry; the disperse inks had the characteristics of a Newtonian fluid. The inkjet printability of disperse inks was investigated by monitoring droplet formation dynamics, where the viscosity and surface tension of disperse ink were 2.78 mPa s and 33.28 mN m−1, respectively. The disperse ink has excellent ejection performance. The printing accuracy of disperse inks was evaluated by inkjet printing quality of lines on untreated polyester fabrics. The fastness properties of printed polyester fabrics were also evaluated and they presented excellent color fastness. Compared with different printed polyester fabrics, the polyester fabrics printed with disperse ink made from water-based polymers have high color strength (K/S) and saturation (C*) values.

Energy storage on demand: ultra-high-rate and high-energy-density inkjet-printed NiO micro-supercapacitors

A NiO nanoparticle-based, inkjet-printable ink and a saturated magnesium perchlorate aqueous gel electrolyte with 1.5 V voltage window were developed and used to fabricate high performance micro-supercapacitors through inkjet printing technology.

Synthesis of UV and thermal dual curing oligomer for solder resist ink using ink‐jet printing

ABSTRACTA novel solder resist ink for inkjet printing containing the ultraviolet (UV) and thermal dual curing oligomer is introduced in this work. Three kinds of acrylic monomers for the synthesis of the oligomer are successful prepared and their structures are determined by Fourier transfer infrared. Both UV curing process and thermostability are monitored under UV differential scanning calorimetry and thermogravimetric analysis. For the photoreaction process, the oligomer using Lauryl methacrylate as the material of copolymerization possesses the highest reactivity and conversion of carbon–carbon double bond. Besides, this kind of oligomer also owns excellent thermostability, just losing 5.9% of its weight at 288 °C. The solder resist inks containing the oligomers and jetting by the inkjet printer are tested with the adhesion, soldering resistance, and other performances, presenting the outstanding heat resistance and wide application prospects. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47428.

Colloidally Stable Monolayer Nanosheets with Colorimetric Responses.

Despite the discovery of chromogenic-layered materials for decades of years, fabrication of colloidally stable monolayer organic 2D nanosheets in aqueous media with colorimetric responses is still challenging. Herein reported is the first solution synthesis of chromic monolayer nanosheets via the topochemical polymerization of self-assembled amphiphilic diacetylenes in aqueous media. The polydiacetylene (PDA) nanosheets are ≈3-4 nm thick in solution and only ≈1.9 nm thick in the dried state, while the lateral size can reach several micrometers. Moreover, the aqueous stability endows PDA nanosheets with excellent processability, which can further assemble into films via vacuum filtration or act as an ink for high-resolution inkjet printing. The filtrated films and printed patterns exhibit fully reversible blue-to-red thermochromism, and the film also displays an interesting reversible colorimetric transition in response to near-infrared light, which is not reported for other PDA-only systems. The present colloidal PDA nanosheets should represent a new kind of chromic organic 2D nanomaterials that may be applied as novel building blocks for developing intelligent hybrid materials and may also find diverse sensing, display and/or anticounterfeiting applications.

Ink-jet printing of a TiO2–10%ZrO2 thin film for oxygen detection using a solution of metal alkoxoacetylacetonates

A solution of metal alkoxoacetylacetonates in isoamyl alcohol was used as a functional ink for ink-jet printing of TiO2–10%ZrO2 thin nanostructured films. It is shown that the anatase crystal lattice is formed during heat treatment of xerogel thin films in air at a temperature of 500 °C. According to the scanning electron microscopy, the particle size of the resulting films was 10–11 nm. The effect of the number of TiO2-ZrO2 deposited layers on resulting 2D-nanomaterial sensitivity to oxygen and other analyte gases (H2, CH4 and CO) at temperatures of 400 and 450 °C is shown.

Surface modification of carbon black by thiol-ene click reaction for improving dispersibility in aqueous phase

Carbon black (CB) particles were firstly encapsulated by γ-Methacryloxypropyltrimethoxysilane (MEMO) using a sol-gel method and then grafted with sodium 3-Mercapto-1-propanesulfonate (MPS) via thiol-ene click reaction. Morphology characterization reveals that modified CB particles have a core-shell structure. Element composition and chemical status derived from X-ray photoelectron spectroscopy (XPS) results prove the grafting of MPS molecules. Moreover, the crystal structure and thermal behavior of modified CB particles were characterized by Raman spectra and Thermogravimetric analysis (TGA) curves, respectively. The modified CB particles exhibit excellent self-dispersing ability in aqueous media and the dispersion has high thermal and centrifugal stability. This research provides a new insight into the preparation of inkjet printing ink with excellent stability.

Preparation and evaluation of (resorcinol – aldehyde) based polymeric dispersants for inkjet printing ink.

Preparation and evaluation of (resorcinol – aldehyde) based polymeric dispersants for inkjet printing ink.

Preparation and evaluation of (resorcinol – aldehyde) based polymeric dispersants for inkjet printing ink

In this study, modification of an amino polyether with resorcinol-aldehyde condensate was performed using four different aldehydes [formaldehyde, glutaraldehyde, butyraldehyde and 4-(N,N-dimethylamino)benzaldehyde] to give dispersants (1 – 5) to be used as dispersing agents for solvent based inkjet inks. The prepared dispersing agents were characterized using FT-IR and GPC. The optical properties and stability efficiency of the ink formulated with the prepared dispersing agents were investigated. The dispersants (1-5) were evaluated for their efficiency in comparison to commercial dispersing agents used in the market. Formulations of dispersants 4 and 5 showed excellent results in comparison to the commercial dispersing agents and have a good potential as effective dispersing agents for solvent based inkjet inks.