Investigation of Inherently Conductive Polymer as Structure Health Monitoring Sensor for Composite

2011 ◽  
Vol 1312 ◽  
Author(s):  
Huaxiang Yang ◽  
Dongsik Kim ◽  
Abhishek K. Singh ◽  
Brady W. Pitts ◽  
Gregory J. Tregre ◽  
...  
Keyword(s):  
Composite Structures ◽  
Linear Thermal Expansion ◽  
Conductive Polymer ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Polymer Sensors ◽  
Jet Printing ◽  
Strain Stress ◽  
Printing Processes ◽  
Aerosol Jet Printing

ABSTRACTA soluble polyaniline was synthesized through emulsion polymerization and characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), viscosity analysis, and coefficient of linear thermal expansion (CLTE) determination. The electrical conductivity is found to reach 1000 S/cm with specific post doping treatments. Multiple printing processes, such as inkjet printing, screen printing and aerosol jet printing etc, make it feasible to print a variety of sensor patterns. The electromechanical response of these sensors was used to measure strain/stress or damage of composite structures under various load conditions expected to be experienced by aircraft. These unique conductive polymer sensors provide a feasible, near real time monitoring system for composites without adding significant additional weight to the structure.

Direct Write Electronics – Thick Films on LTCC

2014 ◽  
Vol 2014 (1) ◽  
pp. 000893-000897 ◽  
Author(s):  
Tim Eastman ◽  
Adam Cook
Keyword(s):  
Cross Sections ◽  
Direct Write ◽  
Industry Standard ◽  
Fluid Dispensing ◽  
Wire Bonds ◽  
Manufacturing Errors ◽  
Jet Printing ◽  
Low Volume ◽  
Printing Processes ◽  
Aerosol Jet Printing

For low volume, high value microelectronic applications reducing cost and time to initial production parts in Low Temperature Cofired Ceramics (LTCC) play a big part in customer satisfaction. Using Direct Write Electronics (DWE) for conductor printing and other structures has the potential to reduce time to production through elimination of intermediate tooling and to reduce waste by applying expensive materials only where they are needed. Additional benefits may be realized by using DWE: wire bonds may be replaced by dispensed conductors; individual layers and parts may be uniquely labeled at the time of printing to improve traceability of product throughout the line and reducing manufacturing errors. This paper investigates using engineered fluid dispensing to print interior and exterior conductors on a demonstration Multi-Chip Module (MCM). Industry standard materials and processes are used to form individual layers of unfired LTCC tape, as well as the forming and filling of interlayer connecting vias with conductive thick film paste. Conductor patterns on each layer are created by dispensing modified Au conductor paste with a commercial three-axis machine with a fine-tipped dispensing pump. Standard processes for collation, lamination, and sintering were followed by aerosol jet printing of Ag ink with a commercial print head mounted on a custom, 6-axis positioning gantry to form wire bond replacements, part identification and individualized markings. Resultant parts are tested for electrical functionality and cross sections are compared to in-progress build photos and line measurements to study the effect of the new printing method vs. structures produced with standard conductor printing processes.

A knowledge transfer framework to support rapid process modeling in aerosol jet printing

2021 ◽  
Vol 48 ◽  
pp. 101264
Author(s):  
Haining Zhang ◽  
Joon Phil Choi ◽  
Seung Ki Moon ◽  
Teck Hui Ngo
Keyword(s):  
Knowledge Transfer ◽  
Process Modeling ◽  
Rapid Process ◽  
Jet Printing ◽  
Aerosol Jet Printing

scholarly journals Biocompatibility studies of polyurethane electrospun membranes based on arginine as chain extender

2021 ◽  
Vol 32 (9) ◽  
Author(s):  
Georgina Alejandra Venegas-Cervera ◽  
Andrés Iván Oliva ◽  
Alejandro Avila-Ortega ◽  
José Manuel Cervantes-Uc ◽  
Leydi Maribel Carrillo-Cocom ◽  
...  
Keyword(s):  
Fourier Transforms ◽  
Cell Attachment ◽  
Human Fibroblasts ◽  
Gel Permeation Chromatography ◽  
Electrospinning Process ◽  
Chain Extender ◽  
Cellular Interaction ◽  
Scanning Calorimetry ◽  
Polyurethane Membranes ◽  
Electrospun Membranes

AbstractElectrospun polymers are an example of multi-functional biomaterials that improve the material-cellular interaction and aimed at enhancing wound healing. The main objective of this work is to fabricate electrospun polyurethane membranes using arginine as chain extender (PUUR) in order to test the fibroblasts affinity and adhesion on the material and the polymer toxicity. Polyurethane membranes were prepared in two steps: (i) the polyurethane synthesis, and ii) the electrospinning process. The membranes were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry techniques. The evaluation of PUUR as a scaffolding biomaterial for growing and developing of cells on the material was realized by LIVE/DEAD staining. The results show that the fluorescent surface area of human fibroblasts (hFB), was greater in control dense membranes made from Tecoflex than in electrospun and dense PUUR. From SEM analysis, the electrospun membranes show relatively uniform attachment of cells with a well-spread shape, while Tecoflex dense membranes show a non-proliferating round shape, which is attributed to the fiber’s structure in electrospun membranes. The cell morphology and the cell attachment assay results reveal the well spreading of hFB cells on the surface of electrospun PUUR membranes which indicates a good response related to cell adhesion.

scholarly journals Recycling Potential for Non-Valorized Plastic Fractions from Electrical and Electronic Waste

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 33
Author(s):  
Laura Strobl ◽  
Thomas Diefenhardt ◽  
Martin Schlummer ◽  
Tanja Leege ◽  
Swetlana Wagner
Keyword(s):  
Flame Retardants ◽  
Electronic Waste ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Separation Processes ◽  
Melt Flow Rate ◽  
Density Fractions ◽  
Material Recycling ◽  
Other Substances ◽  
Electrical And Electronic Waste

This paper describes a study for waste of electrical and electronic equipment (WEEE) to characterise the plastic composition of different mixed plastic fractions. Most of the samples studied are currently excluded from material recycling and arise as side streams in state-of-the-art plastics recycling plants. These samples contain brominated flame retardants (BFR) or other substances of concern listed as persistent organic pollutants or in the RoHS directive. Seventeen samples, including cathode ray tube (CRT) monitors, CRT televisions, flat screens such as liquid crystal displays, small domestic appliances, and information and communication technology, were investigated using density- and dissolution-based separation processes. The total bromine and chlorine contents of the samples were determined by X-ray fluorescence spectroscopy, indicating a substantial concentration of both elements in density fractions above 1.1 g/cm3, most significantly in specific solubility classes referring to ABS and PS. This was further supported by specific flame retardant analysis. It was shown that BFR levels of both polymers can be reduced to levels below 1000 ppm by dissolution and precipitation processes enabling material recycling in compliance with current legislation. As additional target polymers PC and PC-ABS were also recycled by dissolution but did not require an elimination of BFR. Finally, physicochemical investigations of recycled materials as gel permeation chromatography, melt flow rate, and differential scanning calorimetry suggest a high purity and indicate no degradation of the technical properties of the recycled polymers.

scholarly journals Synthesis of Printable Polyvinyl Alcohol for Aerosol Jet and Inkjet Printing Technology

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 220
Author(s):  
Mahmuda Akter Monne ◽  
Chandan Qumar Howlader ◽  
Bhagyashree Mishra ◽  
Maggie Yihong Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Inkjet Printing ◽  
Micro Electro Mechanical System ◽  
Device Fabrication ◽  
Silicon Substrates ◽  
Excellent Candidate ◽  
Jet Printing ◽  
Inkjet Printing Technology ◽  
Transistor Fabrication ◽  
Aerosol Jet Printing

Polyvinyl Alcohol (PVA) is a promising polymer due to its high solubility with water, availability in low molecular weight, having short polymer chain, and cost-effectiveness in processing. Printed technology is gaining popularity to utilize processible solution materials at low/room temperature. This work demonstrates the synthesis of PVA solution for 2.5% w/w, 4.5% w/w, 6.5% w/w, 8.5% w/w and 10.5% w/w aqueous solution was formulated. Then the properties of the ink, such as viscosity, contact angle, surface tension, and printability by inkjet and aerosol jet printing, were investigated. The wettability of the ink was investigated on flexible (Kapton) and non-flexible (Silicon) substrates. Both were identified as suitable substrates for all concentrations of PVA. Additionally, we have shown aerosol jet printing (AJP) and inkjet printing (IJP) can produce multi-layer PVA structures. Finally, we have demonstrated the use of PVA as sacrificial material for micro-electro-mechanical-system (MEMS) device fabrication. The dielectric constant of printed PVA is 168 at 100 kHz, which shows an excellent candidate material for printed or traditional transistor fabrication.

Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Glycidyl Methacrylate ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Protection Efficiency ◽  
Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

Considerations of Aerosol-Jet Printing for the Fabrication of Printed Hybrid Electronic Circuits

2021 ◽  
pp. 102325
Author(s):  
D.R. Hines ◽  
Y. Gu ◽  
A.A. Martin ◽  
P. Li ◽  
J. Fleischer ◽  
...  
Keyword(s):  
Electronic Circuits ◽  
Jet Printing ◽  
Aerosol Jet Printing

scholarly journals Synthesis and Characterization of a Multifunctional Conjugated Polymer

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Emerson C. G. Campos ◽  
Cristiano Zanlorenzi ◽  
Bruno F. Nowacki ◽  
Gabriela M. Miranda ◽  
Denis A. Turchetti ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Molar Mass ◽  
Photophysical Properties ◽  
Gel Permeation Chromatography ◽  
Thermal Characterization ◽  
Polymer Structure ◽  
Synthesis And Characterization ◽  
Metallic Ions ◽  
Scanning Calorimetry

This work reports the synthesis and characterization of a conjugated polymer based on fluorene and terpyridine, namely, poly[(9,9-bis(3-((S)-2-methylbutylpropanoate))fluorene-alt-6,6′-(2,2′:6′,2′′-terpyridin-6-yl)] (LaPPS71). The structure was characterized by 1H and 13C nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy. The molar mass was measured by gel permeation chromatography (GPC). As thermal characterization, the glass transition temperature (Tg) was measured by differential scanning calorimetry (DSC). The polymer structure contains two sites capable of complexation with metallic ions, affording the possibility of obtainment of independent or electronically coupled properties, depending on the complexation site. The photophysical properties were fully explored in solution and solid state, presenting ideal results for the preparation of various metallopolymers, in addition to potential application as a metamaterial, due to the presence of the chiral center in the side chains of the polymer.

Characterization of bi-layered magnetic nanoparticles synthesized via two-step surface-initiated ring-opening polymerization

2015 ◽  
Vol 87 (11-12) ◽  
pp. 1085-1097 ◽  
Author(s):  
Li Wang ◽  
Stefan Baudis ◽  
Karl Kratz ◽  
Andreas Lendlein
Keyword(s):  
Magnetic Nanoparticles ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Polymer Networks ◽  
Gel Permeation Chromatography ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Transmission Electron

AbstractA versatile strategy to integrate multiple functions in a polymer based material is the formation of polymer networks with defined nanostructures. Here, we present synthesis and comprehensive characterization of covalently surface functionalized magnetic nanoparticles (MNPs) comprising a bi-layer oligomeric shell, using Sn(Oct)2 as catalyst for a two-step functionalization. These hydroxy-terminated precursors for degradable magneto- and thermo-sensitive polymer networks were prepared via two subsequent surface-initiated ring-opening polymerizations (ROPs) with ω-pentadecalactone and ε-caprolactone. A two-step mass loss obtained in thermogravimetric analysis and two distinct melting transitions around 50 and 85°C observed in differential scanning calorimetry experiments, which are attributed to the melting of OPDL and OCL crystallites, confirmed a successful preparation of the modified MNPs. The oligomeric coating of the nanoparticles could be visualized by transmission electron microscopy. The investigation of degrafted oligomeric coatings by gel permeation chromatography and 1H-NMR spectroscopy showed an increase in number average molecular weight as well as the presence of signals related to both of oligo(ω-pentadecalactone) (OPDL) and oligo(ε-caprolactone) (OCL) after the second ROP. A more detailed analysis of the NMR results revealed that only a few ω-pentadecalactone repeating units are present in the degrafted oligomeric bi-layers, whereby a considerable degree of transesterification could be observed when OPDL was polymerized in the 2nd ROP step. These findings are supported by a low degree of crystallinity for OPDL in the degrafted oligomeric bi-layers obtained in wide angle X-ray scattering experiments. Based on these findings it can be concluded that Sn(Oct)2 was suitable as catalyst for the preparation of nanosized bi-layered coated MNP precursors by a two-step ROP.

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