scholarly journals Sacrificial Paste for Fabrication of Ceramic Materials by Layer-By-Layer Method

2016 ◽  
Vol 61 (3) ◽  
pp. 1459-1464
Author(s):  
P. Falkowski ◽  
K. Scisel
Keyword(s):  
Melting Point ◽  
Soft Lithography ◽  
Tape Casting ◽  
Ceramic Materials ◽  
Layer By Layer ◽  
Visual Evaluation ◽  
Uv Curable ◽  
Poly Ethylene ◽  
Main Components ◽  
Heating Up

AbstractThe aim of the work was to develop a sacrificial paste suitable for securing channels during shaping of ceramic materials with internal structures via combination of tape casting and soft lithography. Poly(ethylene glycol) methyl ether and polyethylene glycols with different molecular weight were selected as a main components of a sacrificial paste due to their compatibility to UV curable dispersion. The research shows that sacrificial paste should be characterized by proper melting point. This goal was achieved by using a composition of PEG600 with 15wt.%PEG20000 and 10wt.% carbon. The invented sacrificial paste solidify beyond 27°C (melting point). After heating up to 80°C the viscosity of paste is low enough and easily fills the channels with diameter of 150-300μm. What is more, the operational time during free cooling from 80°C to solidification is around 8 minutes what gives enough time for application. Carbon was added as a modifier of rheological properties and as a black dye that helps in visual evaluation of a degree of filling channel. The first test proved that proposed method of preparation of ceramic samples with application of invented sacrificial paste is reliable and can be practically applied.

PEG1000 as a Low Melting and Ecofriendly Solvent for Air Oxidative and Catalyst Free 2,4-Disubstitute Quinazoline Synthesis

2020 ◽  
Vol 17 (9) ◽  
pp. 709-716
Author(s):  
Ebrahim Saeedian Moghadam ◽  
Shahrzad Ghafary ◽  
Mohsen Amini
Keyword(s):  
Melting Point ◽  
High Yield ◽  
Purification Process ◽  
Poly Ethylene Glycol ◽  
Free Condition ◽  
Catalyst Free ◽  
Privileged Scaffold ◽  
Quinazoline Derivatives ◽  
Poly Ethylene ◽  
Work Up

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is the first report about using PEG1000 as a solvent simultaneously with air bubbling as oxidant in quinazoline synthesis. All of the compounds 1-27 were synthesized in high yield with very simple work up and purification process without using column chromatography. All the structures were confirmed using 1H NMR, 13C NMR, IR, MS and elemental analysis.

scholarly journals 3D Printing of High Viscosity Reinforced Silicone Elastomers

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2239
Author(s):  
Nicholas Rodriguez ◽  
Samantha Ruelas ◽  
Jean-Baptiste Forien ◽  
Nikola Dudukovic ◽  
Josh DeOtte ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
New Technologies ◽  
Three Dimensional ◽  
High Viscosity ◽  
Layer By Layer ◽  
Silicone Elastomers ◽  
Uv Curable ◽  
Octet Truss ◽  
Tunable Mechanical Properties

Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.

Cellular responses to novel, micropatterned biomaterials

2008 ◽  
Vol 80 (11) ◽  
pp. 2479-2487 ◽  
Author(s):  
Marga C. Lensen ◽  
Vera A. Schulte ◽  
Jochen Salber ◽  
Mar Diez ◽  
Fabian Menges ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cellular Responses ◽  
Poly Ethylene Glycol ◽  
Uv Curable ◽  
Cellular Behavior ◽  
Remarkable Effect ◽  
Support Cell ◽  
Poly Ethylene ◽  
Line Patterns ◽  
Perfluorinated Polyether

Two UV-curable polymers, i.e., a star-shaped poly(ethylene glycol) (PEG) and a linear perfluorinated polyether (PFPE), are investigated as novel biomaterials in a systematic study of the cellular responses to surface chemistry, topography, and elasticity. Based on the wettability it was expected that the two novel biomaterials were too hydrophilic or -phobic, respectively, to support cell adhesion. Indeed, no cell adhesion was observed on the smooth, unstructured elastomers, whereas the materials showed no cytotoxicity. However, when the materials bear defined, topographic patterns (prepared by UV-based imprinting), cells do react strongly to the surfaces; they adhere, spread, and change their shape depending on the geometry of the features. Typically, cells were found to align along line patterns and "float" on pillar structures. It should be noted that the chemistry of the surface is not altered by the imprinting process, hence, there are no biofunctional molecules present at the surface to aid the cell adhesion. Finally, a remarkable effect of elasticity on the cellular behavior was discovered. Thus, the three parameters of chemistry, topography, and elasticity were investigated in- and interdependently, and it was found that the biomaterials may lose their resistance to protein adsorption and cell adhesion depending on the surface topography.

Interpolymer complexes of poly(sulfonic acid)s and poly(ethylene oxide): an unexpected association

Soft Matter ◽  
2019 ◽  
Vol 15 (45) ◽  
pp. 9318-9324
Author(s):  
Liliana Maldonado ◽  
Gabriel Debais ◽  
Federico Davia ◽  
Lucila P. Méndez De Leo ◽  
Mario Tagliazucchi
Keyword(s):  
Aqueous Solution ◽  
Ethylene Oxide ◽  
Sulfonic Acid ◽  
Layer By Layer ◽  
Interpolymer Complexes ◽  
Layer Deposition ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Hydrogen Bonded

Poly(sulfonic acid)s and poly(ethylene oxide) unexpectedly form novel hydrogen-bonded interpolymer complexes in aqueous solution and on surfaces by layer-by-layer deposition.

Application of Dynamic Masking on Rapid Prototyping

2008 ◽  
Vol 594 ◽  
pp. 261-272
Author(s):  
Chien Nan Chen ◽  
Sheng Jye Hwang ◽  
Huei Huang Lee ◽  
Durn Yuan Huang
Keyword(s):  
Material Processing ◽  
Liquid Crystal ◽  
Rapid Prototyping ◽  
Visible Light ◽  
Laser Scanning ◽  
Uv Light ◽  
Liquid Crystal Display ◽  
Digital Light Processing ◽  
Uv Curable ◽  
Main Components

In rapid prototyping (RP) technologies, curing of UV-curable photopolymers is mainly achieved by the application of laser scanning with limited fabrication speed. The dynamic masking approach can improve the fabrication speed; however, current researches and available systems cure photopolymers with visible light rather than UV light. In this research, we have attempted to develop a UV dynamic masking RP system by implementing digital micro-mirror device (DMD) from digital light processing (DLP) technology and TFT liquid crystal display (LCD) panel. A DLP projector was disassembled and the main components were then recombined to form a dynamic mask generator. Thus, this study has shown the feasibility of obtaining a UV dynamic masking RP system that may be integrated for a UV-curable material processing.

Construction of antibacterial poly(ethylene terephthalate) films via layer by layer assembly of chitosan and hyaluronic acid

2016 ◽  
Vol 143 ◽  
pp. 35-43 ◽  
Author(s):  
Sara del Hoyo-Gallego ◽  
Leyre Pérez-Álvarez ◽  
Flor Gómez-Galván ◽  
Erlantz Lizundia ◽  
Ivo Kuritka ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Ethylene Terephthalate ◽  
Layer By Layer ◽  
Layer By Layer Assembly ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Layer Assembly

Artificial Ceramic Metamaterial with Meshed Grid Structure for Radome Application

2014 ◽  
Vol 893 ◽  
pp. 11-14 ◽  
Author(s):  
Xian Gao Zhang ◽  
Xi Geng Miao ◽  
Xiao Wei Fang ◽  
Hai Lian Wang ◽  
Ling Zhang ◽  
...  
Keyword(s):  
Melting Point ◽  
High Temperatures ◽  
Quartz Glass ◽  
Screen Printing ◽  
Dielectric Material ◽  
Tape Casting ◽  
Unit Cell ◽  
Grid Structure ◽  
Transmission Characteristics

We investigated a novel artificial metamaterial that includes two plates of quartz glass dielectric material and a Ag microstructure sandwiched between the two plates. The Ag grid layer was designed and subsequently prepared by tape casting and screen printing. The transmission characteristics of this metamaterial were able to be controlled by adjusting the geometry parameters of the Ag grid such as the width of the strip and the size of the unit cell. Our work has demonstrated the possibility that the ceramic metamaterial can be used as a transmission material capable of work at high temperatures below the melting point of the metal.

Fast-Switching, High-Contrast Electrochromic Thin Films Prepared Using Layer-by-Layer Assembly of Charged Species

2004 ◽  
Vol 846 ◽  
Author(s):  
Jaime C. Grunlan
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Color Change ◽  
Contrast Ratio ◽  
Deposition Process ◽  
Layer By Layer ◽  
High Contrast ◽  
Switching Speed ◽  
Order Of Magnitude ◽  
Poly Ethylene

ABSTRACTThin films were prepared by depositing alternating layers of tungstate anion (WO42-) and poly(4-vinylpyridine-co-styrene) (PVP-S) onto an electrode from aqueous solutions. These films have very high contrast (CR > 8) relative to equivalent films prepared using poly(ethylene dioxythiophene) (PEDOT), but suffer from slow color change due to poor electrical conductivity. The switching time of the tungstate-based films was decreased by an order of magnitude, from 30 seconds down to three, by adding layers of indium tin oxide (ITO) particles stabilized with poly(diallyldimethylammonium chloride) (PDDA). In this case, a four-layer repeating structure was created (i.e., PVP-S and PDDA-ITO were each deposited every fourth layer). Unlike tungstate, ITO has a high intrinsic conductivity (∼ 104 S/cm) that accounts for the dramatic increase in the switching speed. It is only through the nanometer-scale control of film architecture, provided with the layer-by-layer (LbL) deposition process, that switching speed and contrast ratio can be optimized simultaneously.

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