Significant Enhancement of Thermal Conductivity in Segregated (GnPs&MWCNTs)@Polybenzoxazine/(Polyether ether ketone) -based Composites with Excellent Electromagnetic Shielding

2021 ◽  
pp. 134049
Author(s):  
Rui Chen ◽  
Qingxia He ◽  
Xue Li ◽  
Fengyu Wen ◽  
Lin Cheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electromagnetic Shielding ◽  
Significant Enhancement ◽  
Polyether Ether Ketone ◽  
Ether Ketone

Mechanical and thermal performance of PEEK/PEI blend matrix reinforced with surface modified halloysite nanotubes

2021 ◽  
pp. 089270572110286
Author(s):  
Abrar Ahamad ◽  
Pradeep Kumar
Keyword(s):  
Mechanical Properties ◽  
Fourier Transform ◽  
Research Work ◽  
Halloysite Nanotubes ◽  
Morphological Properties ◽  
Significant Enhancement ◽  
Degradation Temperature ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Surface Modified

The present research work investigates the effect of modified halloysite nanotubes (mHNTs) on the mechanical, thermal, and morphological properties of polyether ether ketone (PEEK) and polyetherimide (PEI). The developed PEEK/PEI blend matrix with 1 wt% of mHNTs shows a significant enhancement in mechanical properties like tensile, flexural, hardness, and impact. The developed blend matrix of PEEK/PEI matrix with mHNTs shows a significant enhancement of 25% in storage modulus (E′) and 13°C in glass transition temperature (Tg). In addition, an appreciable improvement of 26°C observed in maximum degradation temperature (Tmax). The effectiveness of the dispersion of mHNTs in the PEEK/PEI blend matrix was investigated by using SEM and TEM micrographs. The micrographs revealed that the mHNTs are uniformly dispersed in the PEEK/PEI matrix. The possible interaction of HNTs with PEEK/PEI and mHNTs with PEEK/PEI matrix were analyzed by Fourier Transform Infrared Spectroscopy (FTIR).

scholarly journals Encapsulation of Capacitive Micromachined Ultrasonic Transducers (CMUTs) for the Acoustic Communication between Medical Implants

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Jorge Oevermann ◽  
Peter Weber ◽  
Steffen H. Tretbar
Keyword(s):  
Data Security ◽  
Ultrasonic Transducers ◽  
Surrounding Tissue ◽  
Center Frequency ◽  
Medical Implants ◽  
Research Groups ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Polyether Ether Ketone ◽  
High Bandwidth ◽  
Ether Ketone

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.

scholarly journals Interfacial Fracture Toughness Comparison of Three Indirect Resin Composites to Dentin and Polyether Ether Ketone Polymer

2020 ◽  
Vol 14 (03) ◽  
pp. 456-461
Author(s):  
Rayhaneh Khalesi ◽  
Mahdi Abbasi ◽  
Zahra Shahidi ◽  
Masoumeh Hasani Tabatabaei ◽  
Zohreh Moradi
Keyword(s):  
Fracture Toughness ◽  
Bond Strength ◽  
Testing Machine ◽  
Composite Resins ◽  
High Wear Resistance ◽  
Luting Cements ◽  
Anterior Teeth ◽  
Polyether Ether Ketone ◽  
Ether Ketone

Abstract Objectives Advances in laboratory composites and their high wear resistance and fracture toughness have resulted in their growing popularity and increasing use for dental restorations. This study sought to assess the fracture toughness of three indirect composites bonded to dental substrate and polyether ether ketone (PEEK) polymer. Materials and Methods This in vitro study was conducted on two groups of dental and polymer substrates. Each substrate was bonded to three indirect composite resins. Sixty blocks (3 × 3 × 12 mm) were made of sound bovine anterior teeth and PEEK polymer. Sixty blocks (3 × 3 × 12 mm) were fabricated of CRIOS (Coltene, Germany), high impact polymer composite (HIPC; Bredent, Germany), and GRADIA (Indirect; GC, Japan) composite resins. Composites were bonded to dentin using Panavia F 2.0 (Kuraray, Japan). For bonding to PEEK, Combo.lign (Bredent) and Visio.Link (Bredent) luting cements were used. In all samples, a single-edge notch was created by a no. 11 surgical blade at the interface. The samples were subjected to 3,500 thermal cycles, and their fracture toughness was measured in a universal testing machine (Zwick/Roell, Germany) by application of four-point flexural load. Statistical Analysis Data were analyzed using one-way analysis of variance, Kruskal–Wallis. Results The fracture toughness of CRIOS–PEEK interface was significantly higher than HIPC–PEEK. The fracture toughness of GRADIA–PEEK was not significantly different from that of HIPC and CRIOS. The fracture toughness of GRADIA–dentin was significantly higher than HIPC–dentin. Conclusion Considering the limitations of this study, GRADIA has the highest bond strength to dentin, while CRIOS shows the highest bond strength to PEEK.

scholarly journals Adhesion Behaviour of Primary Human Osteoblasts and Fibroblasts on Polyether Ether Ketone Compared with Titanium under In Vitro Lipopolysaccharide Incubation

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2739 ◽  
Author(s):  
Korbinian Benz ◽  
Andreas Schöbel ◽  
Marisa Dietz ◽  
Peter Maurer ◽  
Jochen Jackowski
Keyword(s):  
Gene Expression ◽  
Protein Level ◽  
Binding Protein ◽  
Sem Images ◽  
Human Osteoblasts ◽  
Polyether Ether Ketone ◽  
Primary Human Osteoblasts ◽  
Titanium Surfaces ◽  
Ether Ketone

The aim of this in vitro pilot study was to analyse the adhesion behaviour of human osteoblasts and fibroblasts on polyether ether ketone (PEEK) when compared with titanium surfaces in an inflammatory environment under lipopolysaccharide (LPS) incubation. Scanning electron microscopy (SEM) images of primary human osteoblasts/fibroblasts on titanium/PEEK samples were created. The gene expression of the LPS-binding protein (LBP) and the LPS receptor (toll-like receptor 4; TLR4) was measured by real-time polymerase chain reaction (PCR). Immunocytochemistry was used to obtain evidence for the distribution of LBP/TLR4 at the protein level of the extra-cellular-matrix-binding protein vinculin and the actin cytoskeleton. SEM images revealed that the osteoblasts and fibroblasts on the PEEK surfaces had adhesion characteristics comparable to those of titanium. The osteoblasts contracted under LPS incubation and a significantly increased LBP gene expression were detected. This was discernible at the protein level on all the materials. Whereas no increase of TLR4 was detected with regard to mRNA concentrations, a considerable increase in the antibody reaction was detected on all the materials. As is the case with titanium, the colonisation of human osteoblasts and fibroblasts on PEEK samples is possible under pro-inflammatory environmental conditions and the cellular inflammation behaviour towards PEEK is lower than that of titanium.

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