scholarly journals High-performance 3D printing of hydrogels by water-dispersible photoinitiator nanoparticles

2016 ◽  
Vol 2 (4) ◽  
pp. e1501381 ◽  
Author(s):  
Amol A. Pawar ◽  
Gabriel Saada ◽  
Ido Cooperstein ◽  
Liraz Larush ◽  
Joshua A. Jackman ◽  
...  
Keyword(s):  
3D Printing ◽  
Aqueous Solutions ◽  
High Performance ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Water Soluble ◽  
Visible Range ◽  
Digital Light Processing ◽  
Uv Curable ◽  
Water Dispersible

In the absence of water-soluble photoinitiators with high absorbance in the ultraviolet (UV)–visible range, rapid three-dimensional (3D) printing of hydrogels for tissue engineering is challenging. A new approach enabling rapid 3D printing of hydrogels in aqueous solutions is presented on the basis of UV-curable inks containing nanoparticles of highly efficient but water-insoluble photoinitiators. The extinction coefficient of the new water-dispersible nanoparticles of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) is more than 300 times larger than the best and most used commercially available water-soluble photoinitiator. The TPO nanoparticles absorb significantly in the range from 385 to 420 nm, making them suitable for use in commercially available, low-cost, light-emitting diode–based 3D printers using digital light processing. The polymerization rate at this range is very fast and enables 3D printing that otherwise is impossible to perform without adding solvents. The TPO nanoparticles were prepared by rapid conversion of volatile microemulsions into water-dispersible powder, a process that can be used for a variety of photoinitiators. Such water-dispersible photoinitiator nanoparticles open many opportunities to enable rapid 3D printing of structures prepared in aqueous solutions while bringing environmental advantages by using low-energy curing systems and avoiding the need for solvents.

scholarly journals Optimization of Printing Parameters for Digital Light Processing 3D Printing of Hollow Microneedle Arrays

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1837
Author(s):  
Essyrose Mathew ◽  
Giulia Pitzanti ◽  
Ana L. Gomes dos Santos ◽  
Dimitrios A. Lamprou
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Mechanical Strength ◽  
Print Quality ◽  
Digital Light Processing ◽  
Uv Curable ◽  
Microneedle Arrays ◽  
Uv Curable Resin ◽  
Viable Method ◽  
Printing Parameters

3D printing is an emerging technology aiming towards personalized drug delivery, among many other applications. Microneedles (MN) are a viable method for transdermal drug delivery that is becoming more popular for delivery through the skin. However, there is a need for a faster fabrication process with potential for easily exploring different geometries of MNs. In the current study, a digital light processing (DLP) method of 3D printing for fabrication of hollow MN arrays using commercial UV curable resin was proposed. Print quality was optimised by assessing the effect of print angle on needle geometries. Mechanical testing of MN arrays was conducted using a texture analyser. Angled prints were found to produce prints with geometries closer to the CAD designs. Curing times were found to affect the mechanical strength of MNs, with arrays not breaking when subjected to 300 N of force but were bent. Overall, DLP process produced hollow MNs with good mechanical strength and depicts a viable, quick, and efficient method for the fabrication of hollow MN arrays.

A flexible, lightweight and stretchable all-solid-state supercapacitor based on warp-knitted stainless-steel mesh for wearable electronics

2022 ◽  
pp. 004051752110698
Author(s):  
Chuanli Su ◽  
Guangwei Shao ◽  
Qinghua Yu ◽  
Yaoli Huang ◽  
Jinhua Jiang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Performance ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Three Dimensional ◽  
Rate Capability ◽  
Cycling Stability ◽  
Wearable Electronics ◽  
Light Emitting ◽  
Dimensional Network

Highly conductive, flexible, stretchable and lightweight electrode substrates are essential to meet the future demand on supercapacitors for wearable electronics. However, it is difficult to achieve the above characteristics simultaneously. In this study, ultrafine stainless-steel fibers (with a diameter of ≈30 μm) are knitted into stainless-steel meshes (SSMs) with a diamond structure for the fabrication of textile stretchable electrodes and current collectors. The electrodes are fabricated by utilizing an electrodeposited three-dimensional network graphene framework and poly(3,4-ethylenedioxythiophene) (PEDOT) coating on the SSM substrates via a two-step electrodeposition process, which show a specific capacitance of 77.09 F g−1 (0.14 A g−1) and superb cycling stability (91% capacitance retention after 5000 cycles). Furthermore, the assembled flexible stretchable supercapacitor based on the PEDOT/reduced graphene oxide (RGO)@SSM electrodes exhibits an areal capacitance (53 mF cm−2 at 0.1 mA cm−2), a good cycling stability (≈73% capacitance retention after 5000 cycles), rate capability (36 mF cm−2 at 5 mA cm−2), stretchable stability (≈78% capacitance retention at 10% strain for 500 stretching cycles) and outstanding flexibility and stability under various bending deformations. The assembled supercapacitors can illuminate a thermometer and a light-emitting diode, demonstrating their potential application as stretchable supercapacitors. This simple and low-cost method developed for fabricating lightweight, stretchable and stable high-performance supercapacitors offers new opportunities for future stretchable electronic devices.

scholarly journals Rapid Planar Chromatographic Analysis of 25 Water-Soluble Dyes Used as Food Additives

2009 ◽  
Vol 92 (3) ◽  
pp. 745-756 ◽  
Author(s):  
Gertrud E Morlock ◽  
Claudia Oellig
Keyword(s):  
High Performance ◽  
Food Additives ◽  
Correlation Coefficients ◽  
Water Soluble ◽  
Visible Range ◽  
Application Development ◽  
Calibration Curves ◽  
Digital Evaluation ◽  
Relative Standard ◽  
Total Analysis

Abstract A rapid planar chromatographic method for identification and quantification of 25 water-soluble dyes in food was developed. In a horizontal developing chamber, the chromatographic separation on silica gel 60F254 high-performance thin-layer chromatography plates took 12 min for 40 runs in parallel, using 8 mL ethyl acetatemethanolwateracetic acid (65 + 23 + 11 + 1, v/v/v/v) mobile phase up to a migration distance of 50 mm. However, the total analysis time, inclusive of application and evaluation, took 60 min for 40 runs. Thus, the overall time/run can be calculated as 1.5 min with a solvent consumption of 200 L. A sample throughput of 1000 runs/8 h day can be reached by switching between the working stations (application, development, and evaluation) in a 20 min interval, which triples the analysis throughput. Densitometry was performed by absorption measurement using the multiwavelength scan mode in the UV and visible ranges. Repeatabilities [relative standard deviation (RSD), 4 determinations] at the first or second calibration level showed precisions of mostly 2.7, ranging between 0.2 and 5.2. Correlation coefficient values (R 0.9987) and RSD values (4.2) of the calibration curves were highly satisfactory using classical quantification. However, digital evaluation of the plate image was also used for quantification, which resulted in RSD values of the calibration curves of mostly 3.0, except for two 6.0. The method was applied for the analysis of some energy drinks and bakery ink formulations, directly applied after dilution. By recording of absorbance spectra in the visible range, the identities of the dyes found in the samples were ascertained by comparison with the respective standard bands (correlation coefficients 0.9996). If necessary for confirmation, online mass spectra were recorded within a minute.

Low-cost automated biochemical phenotyping for optimised nutrient quality components in ryegrass breeding

2016 ◽  
Vol 67 (8) ◽  
pp. 888 ◽  
Author(s):  
L. W. Pembleton ◽  
J. Wang ◽  
G. C. Spangenberg ◽  
J. W. Forster ◽  
N. O. I. Cogan
Keyword(s):  
Protein Content ◽  
High Performance ◽  
Near Infrared ◽  
Low Cost ◽  
Forage Quality ◽  
Farming System ◽  
Water Soluble ◽  
Plant Protein ◽  
Soluble Carbohydrate ◽  
Use Efficiency

Quantification of forage quality is essential for the identification of elite genotypes in forage grass breeding. Perennial ryegrass is the most important temperate species for global pastoral agriculture. However, the protein content of ryegrass generally exceeds the requirements of a grazing animal, and the ratio of water soluble carbohydrate (WSC) to protein is too low for efficient protein utilisation. This results in poor nitrogen use efficiency (NUE) in the farming system by livestock, and hence limits optimal animal production. New ryegrass cultivars with optimised WSC and protein content are desirable for farming efficiencies. Several methods are available for quantification of WSC and plant protein (such as near-infrared spectroscopy [NIRS] and high performance liquid chromatography [HPLC]). However, such methods are labour-intensive, low-throughput and cost-prohibitive for commercial breeding programs, which typically need to assess thousands of samples annually. An accurate high-throughput micro-plate-based protocol has been developed and validated, with the ability to simultaneously process and quantify WSC and plant protein with a high level of automation, and an increase in sample processing of ~10-fold compared with commonly-used methods, along with a 3-fold cost reduction. As WSC and protein are extracted simultaneously and quantified within micro-plates, consumable costs are minimised with optimal reagent use efficiency, resulting in a low per sample cost that is suitable for commercial pasture breeding companies. This is the first demonstration of a forage quality phenotyping protocol suitable for broad-scale application, and will allow breeders to select elite genotypes based not only on visual assessment but also on WSC : protein ratios for improved ruminant nutrition.

Highly Stretchable and UV Curable Elastomers for Digital Light Processing Based 3D Printing

2017 ◽  
Vol 29 (15) ◽  
pp. 1606000 ◽  
Author(s):  
Dinesh K. Patel ◽  
Amir Hosein Sakhaei ◽  
Michael Layani ◽  
Biao Zhang ◽  
Qi Ge ◽  
...  
Keyword(s):  
3D Printing ◽  
Digital Light Processing ◽  
Uv Curable ◽  
Highly Stretchable

scholarly journals Printability Study of a Conductive Polyaniline/Acrylic Formulation for 3D Printing

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2068
Author(s):  
Goretti Arias-Ferreiro ◽  
Ana Ares-Pernas ◽  
Aurora Lasagabáster-Latorre ◽  
Nora Aranburu ◽  
Gonzalo Guerrica-Echevarria ◽  
...  
Keyword(s):  
3D Printing ◽  
Low Cost ◽  
Electronic Devices ◽  
Maximum Amount ◽  
Gel Point ◽  
Digital Light Processing ◽  
Conductive Composites ◽  
Printing Quality ◽  
Conductive Polyaniline ◽  
Pure Resin

There is need for developing novel conductive polymers for Digital Light Processing (DLP) 3D printing. In this work, photorheology, in combination with Jacobs working curves, efficaciously predict the printability of polyaniline (PANI)/acrylate formulations with different contents of PANI and photoinitiator. The adjustment of the layer thickness according to cure depth values (Cd) allows printing of most formulations, except those with the highest gel point times determined by photorheology. In the working conditions, the maximum amount of PANI embedded within the resin was ≃3 wt% with a conductivity of 10−5 S cm−1, three orders of magnitude higher than the pure resin. Higher PANI loadings hinder printing quality without improving electrical conductivity. The optimal photoinitiator concentration was found between 6 and 7 wt%. The mechanical properties of the acrylic matrix are maintained in the composites, confirming the viability of these simple, low-cost, conductive composites for applications in flexible electronic devices.

scholarly journals Rubber Seed Oil-Based UV-Curable Polyurethane Acrylate Resins for Digital Light Processing (DLP) 3D Printing

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5455
Author(s):  
Yun Hu ◽  
Guoqiang Zhu ◽  
Jinshuai Zhang ◽  
Jia Huang ◽  
Xixi Yu ◽  
...  
Keyword(s):  
3D Printing ◽  
Seed Oil ◽  
Plant Oil ◽  
Rubber Seed Oil ◽  
Simple Method ◽  
Pencil Hardness ◽  
Digital Light Processing ◽  
Uv Curable ◽  
Rubber Seed ◽  
Polyurethane Acrylate

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.

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