scholarly journals Probing the Nanoscale Heterogeneous Mixing in a High-Performance Polymer Blend

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 192
Author(s):  
Alexander Paul Fellows ◽  
Debashis Puhan ◽  
Janet S. S. Wong ◽  
Michael T. L. Casford ◽  
Paul B. Davies
Keyword(s):  
High Performance ◽  
Domain Boundary ◽  
Temperature Stability ◽  
Chemical Information ◽  
High Temperature Stability ◽  
Force Microscopy ◽  
Domain Structures ◽  
Wide Range ◽  
Physical Mixing ◽  
Cantilever Probes

The blend of polyetheretherketone (PEEK) and polybenzimidazole (PBI) produces a high-performance blend (PPB) that is a potential replacement material in several industries due to its high temperature stability and desirable tribological properties. Understanding the nanoscale structure and interface of the two domains of the blend is critical for elucidating the origin of these desirable properties. Whilst achieving the physical characterisation of the domain structures is relatively uncomplicated, the elucidation of structures at the interface presents a significant experimental challenge. In this work, we combine atomic force microscopy (AFM) with an IR laser (AFM-IR) and thermal cantilever probes (nanoTA) to gain insights into the chemical heterogeneity and extent of mixing within the blend structure for the first time. The AFM-IR and nanoTA measurements show that domains in the blend are compositionally different from those of the pure PEEK and PBI polymers, with significant variations observed in a transition region several microns wide in proximity to domain boundary. This strongly points to physical mixing of the two components on a molecular scale at the interface. The versatility intrinsic to the combined methodology employed in this work provides nano- and microscale chemical information that can be used to understand the link between properties of different length scales across a wide range of materials.

scholarly journals High-Performance Temporary Adhesives for Wafer Bonding Applications

2006 ◽  
Vol 970 ◽  
Author(s):  
Rama Puligadda ◽  
Sunil Pillalamarri ◽  
Wenbin Hong ◽  
Chad Brubaker ◽  
Markus Wimplinger ◽  
...  
Keyword(s):  
High Performance ◽  
Heat Dissipation ◽  
Driving Forces ◽  
Three Dimensional ◽  
Temperature Stability ◽  
Thickness Variation ◽  
High Temperature Stability ◽  
Process Step ◽  
Wide Range ◽  
Wafer Thinning

ABSTRACTMyriad structures for stacking chips, power devices, smart cards, and thin substrates for processors have one thing in common: thin silicon. Wafer thinning will soon be an essential process step for most of the devices fabricated and packaged henceforth. The key driving forces for thinned wafers are improved heat dissipation, three-dimensional stacking, reduced electrical resistance, and substrate flexibility. Handling of thin and ultrathin substrates however is not trivial because of their fragility and tendency to warp and fold. The thinned substrates need to be supported during the backside grinding process and through the subsequent processes such as lithography, deposition, etc. Using temporary adhesives to attach the processed device wafer to a rigid carrier wafer offers an efficient solution. The key requirements for such materials are ease of application, coating uniformity with minimal thickness variation across the wafer, good adhesion to a wide variety of surfaces, thermal stability in processes such as dielectric deposition and metallization, and ease of removal to allow high throughput. An additional requirement for these materials is stability in harsh chemical environments posed by processes such as etching and electroplating. Currently available materials meet only a subset of these requirements. None of them meet the requirement of high-temperature stability combined with ease of removal. We have developed adhesives that meet a wide range of post-thinning operating temperatures. Additionally, the materials are soluble in industry-accepted safe solvents and can be spin-applied to required thicknesses and uniformity. Above all, the coatings can be removed easily without leaving any residue. This paper reports on the development of a wide range of temporary adhesives that can be used in wafer thinning applications while applying both novel and conventional bonding and debonding methods.

scholarly journals Magnetic properties of (Bi1−xLax)(Fe,Co)O3 films fabricated by a pulsed DC reactive sputtering and demonstration of magnetization reversal by electric field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Munusamy Kuppan ◽  
Daichi Yamamoto ◽  
Genta Egawa ◽  
Sivaperuman Kalainathan ◽  
Satoru Yoshimura
Keyword(s):  
Electric Field ◽  
Magnetization Reversal ◽  
High Performance ◽  
Magnetic Domain ◽  
Magnetic Film ◽  
Film Plane ◽  
Force Microscopy ◽  
Domain Structures ◽  
Pulsed Dc ◽  
Submicron Scale

Abstract(Bi1−xLax)(Fe,Co)O3 multiferroic magnetic film were fabricated using pulsed DC (direct current) sputtering technique and demonstrated magnetization reversal by applied electric field. The fabricated (Bi0.41La0.59)(Fe0.75Co0.25)O3 films exhibited hysteresis curves of both ferromagnetic and ferroelectric behavior. The saturated magnetization (Ms) of the multiferroic film was about 70 emu/cm3. The squareness (S) (= remanent magnetization (Mr)/Ms) and coercivity (Hc) of perpendicular to film plane are 0.64 and 4.2 kOe which are larger compared with films in parallel to film plane of 0.5 and 2.5 kOe. The electric and magnetic domain structures of the (Bi0.41La0.59)(Fe0.75Co0.25)O3 film analyzed by electric force microscopy (EFM) and magnetic force microscopy (MFM) were clearly induced with submicron scale by applying a local electric field. This magnetization reversal indicates the future realization of high performance magnetic device with low power consumption.

Tailored Solutions for Off-Shore Applications by Plazjet Sprayed Coatings

1997 ◽  
Author(s):  
F. Ladru ◽  
E. Lugscheider ◽  
H. Jungklaus ◽  
C. Herbst ◽  
I. Kvernes
Keyword(s):  
Process Control ◽  
Thermal Spraying ◽  
Temperature Stability ◽  
Hard Coatings ◽  
High Temperature Stability ◽  
Coating Quality ◽  
Large Structures ◽  
Wide Range ◽  
Sprayed Coatings ◽  
Suitable Process

Abstract For very large structures and parts in critical environments, a materials solution often cannot be found by using one material. The specific desired properties for those structures, like stiffness, ductility, high temperature stability, corrosion resistance, etc. are difficult to fulfill with only one material. In this case a solution may be found by using coatings and design their specific properties to replenish each other by their combination. The Thermal Spraying processes offer the necessary flexibility of producing thin to thick, ductile, soft to hard coatings while due to the wide range of process temperatures it is possible to process a wide range of materials, both as coating and structure. In this paper the some recent and important developments in Thermal Spraying to produce coatings for technical demanding structures will be described. These developments consist of High Power Plasma Spraying, powder- and process control development. To ensure process consistency during long spraying times and to apply reproducible coating quality a suitable process control is of great importance and the development of temperature control by Pyrometry and Thermography will be presented. The example will be drawn according to the application of a coating on a ball valve for off-shore and ship diesel engine parts (piston and valve).

High-Temperature Spin-On Adhesives for Temporary Wafer Bonding

2007 ◽  
Vol 4 (3) ◽  
pp. 105-111 ◽  
Author(s):  
S. Pillalamarri ◽  
R. Puligadda ◽  
C. Brubaker ◽  
M. Wimplinger ◽  
S. Pargfrieder
Keyword(s):  
High Temperature ◽  
Wafer Bonding ◽  
Heat Dissipation ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Performance Requirements ◽  
Wide Range ◽  
Bonding Properties ◽  
Partial List ◽  
Wafer Thinning

Wafer thinning has been effectively used to improve heat dissipation in power devices and to fabricate flexible substrates, small chip packages, and multiple chips in a package. Wafer handling has become an important issue due to the tendency of thinned wafers to warp and fold. Thinned wafers need to be supported during the backgrinding process, lithography, deposition, etc. Temporary wafer bonding using removable adhesives provides a feasible route to wafer thinning. Existing adhesives meet only a partial list of performance requirements. They do not meet the requirements of high-temperature stability combined with ease of removal. This paper reports on the development of a wide range of temporary adhesives to be used in wafer thinning applications that use both novel and conventional bonding and debonding methods. We have developed a series of novel removable high-temperature spin-on adhesives with excellent bonding properties and a wide range of operating temperatures for bonding and/or debonding to achieve a better processing window.

scholarly journals Evaluation of a Cold-Mixed High-Performance Polyurethane Mixture

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sun Min ◽  
Yufeng Bi ◽  
Mulian Zheng ◽  
Sai Chen ◽  
Jingjing Li
Keyword(s):  
Energy Consumption ◽  
High Performance ◽  
Greenhouse Gas Emission ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Water Stability ◽  
High Temperature Stability ◽  
Forming Mechanism ◽  
And Performance

The energy consumption and greenhouse gas emission of asphalt pavement have become a very serious global problem. The high-temperature stability and durability of polyurethane (PU) are very good. It is studied as an alternative binder for asphalt recently. However, the strength-forming mechanism and the mixture structure of the PU mixture are different from the asphalt mixture. This work explored the design and performance evaluation of the PU mixture. The PU content of mixtures was determined by the creep slope (K), tensile strength ratios (TSR), immersion Cantabro loss (ICL), and the volume of air voids (VV) to ensure better water stability. The high- and low-temperature stability, water stability, dynamic mechanical property, and sustainability of the PU mixture were evaluated and compared with those of the stone matrix asphalt mixture (SMA). The test results showed that the dynamic stability and bending strain of the PU mixture were about 7.5 and 2.3 times of SMA. The adhesion level of PU and the basalt aggregate was one level greater than the limestone, and basalt aggregates were proposed to use in the PU mixture to improve water stability. Although the initial TSR and ICL of PU mixture were lower, the long-term values were higher; the PUM had better long-term water damage resistance. The dynamic modulus and phase angles (φ) of the PU mixture were much higher. The energy consumption and CO2 emission of the PU mixture were lower than those of SMA. Therefore, the cold-mixed PU mixture is a sustainable material with excellent performance and can be used as a substitute for asphalt mixture.

Hexaaluminate Catalysts for Fuel Reforming

2008 ◽  
Author(s):  
Nicholas E. McGuire ◽  
Neal P. Sullivan ◽  
Robert J. Kee ◽  
Huayang Zhu ◽  
James A. Nabity ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Exchange Process ◽  
Catalyst Support ◽  
Temperature Stability ◽  
Metal Exchange ◽  
High Temperature Stability ◽  
Fuel Reforming ◽  
Transmission Electron ◽  
Wide Range ◽  
Hexaaluminate Catalysts

Hexaaluminate catalysts offer excellent high-temperature stability compared to the equivalent metal-based catalysts. Their stability also lends well to use as a catalyst support. However, use of novel hexaaluminates is limited in fuel processing for fuel-cell applications. In this paper, we report on the performance of hexaaluminates as a catalyst support in the steam reforming of methane. The hexaaluminates are synthesized by a metal-exchange process using alumoxane precursors that enable a wide range of metal substitutions. Performance is evaluated using a unique stagnation-flow reactor that enables detailed probing of the boundary layer above the catalyst-impregnated stagnation surface. Experimental results are compared with models to understand fundamental reaction kinetics and optimize catalyst performance. RhSr-substituted hexaaluminates with a Rh impregnation are shown to yield the best performance. Scanning- and Transmission-Electron Microscopy are used to characterize the different types of hexaaluminates, and to examine the effect of aging on catalyst structure.

High-performance, high-temperature piezoelectric BiB3O6 crystals

2015 ◽  
Vol 3 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Fapeng Yu ◽  
Qingming Lu ◽  
Shujun Zhang ◽  
Hewei Wang ◽  
Xiufeng Cheng ◽  
...  
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Piezoelectric Properties ◽  
Temperature Stability ◽  
Piezoelectric Sensor ◽  
High Temperature Stability ◽  
Sensor Applications

BiB3O6 crystals possess large piezoelectric coefficients and high-temperature stability of their piezoelectric properties, which is promising for piezoelectric sensor applications.

Fluoroelastomers

1973 ◽  
Vol 46 (3) ◽  
pp. 619-652 ◽  
Author(s):  
R. G. Arnold ◽  
A. L. Barney ◽  
D. C. Thompson
Keyword(s):  
Developmental Stage ◽  
High Performance ◽  
Vinylidene Fluoride ◽  
Temperature Stability ◽  
Significant Degree ◽  
High Temperature Stability ◽  
Vinyl Ethers ◽  
Carbon Carbon Bond ◽  
Degree Of Stability ◽  
New Generation

Abstract The importance of fluorine in polymer chemistry has been known since the discovery of poly (tetrafluoroethylene) in 1938. Highly fluorinated polymers are very stable and have remarkable resistance to oxidative attack, flame, chemicals, and solvents. This stability has been attributed to the strength of the carbon—fluorine bond compared to that of the carbon—carbon bond, to steric hindrance, and to strong Van der Waals forces. The synthesis of elastomeric polymers containing enough fluorine to impart a significant degree of stability was not achieved until the mid-1950's. Since then a multitude of fluoroelastomers have been reported, but, of these, only certain copolymers of vinylidene fluoride, and fluorosilicone polymers have become commercially important. Recently, however, perfluoroelastomers based on perfluoro (alkyl vinyl ethers) and tetrafluoroethylene have been shown to possess an even greater degree of high temperature stability than do the fluoroelastomers hitherto available. These perfluoroelastomers also are essentially inert to most chemicals and solvents. Copolymers of perfluoro (alkyl vinyl ethers) with partially fluorinated monomers also have been developed that give better flexibility at low temperature. These polymers, now at the developmental stage, appear to be the forerunners of a new generation of superior high-performance elastomers. The discussion that follows will concern firstly, the commercial fluoroelastomers; secondly, those that show commercial promise and might be considered semi-commercial or at the developmental stage but which are available only in limited developmental quantities; and thirdly, those reported in the literature that, so far at least, have been of research interest only. In this last category, polymers will not be included which contain so little fluorine that performance characteristics are not substantially enhanced. For example fluoroprene [poly(2-fluorobutadiene)] and copolymers with nonfluorinated, olefin monomers in which the latter predominate will not be included.

scholarly journals Effect of Si Addition on Mechanical and Electrochemical Properties of Al-Fe-Cu-La Alloy for Current Collector of Lithium Battery

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1072 ◽  
Author(s):  
Xu ◽  
Ding ◽  
Yang ◽  
Zhang ◽  
Gao ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
High Performance ◽  
Lithium Ion ◽  
Temperature Stability ◽  
Current Collector ◽  
High Temperature Stability ◽  
X Ray Diffraction ◽  
Tafel Polarization ◽  
Increasing Demand ◽  
Si Addition

The increasing demand for high-performance current collectors of lithium ion secondary batteries requires that the employed aluminum alloys have better mechanical properties and superior electrochemical performance. The effect of Si addition on the microstructure, tensile and electrochemical performance of Al-Fe-Cu-La alloy was investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, a tensile test, conductivity test and Tafel polarization curve test. Experimental results indicated that Si addition to the Al-Fe-Cu-La alloy helped to refine the longitudinal grain size of the alloy. The Si-containing phase (AlFeSi) nucleated and grew along the surface of the AlFeLa phase. The Si addition to the Al-Fe-Cu-La alloy could greatly increase the tensile strength in the temperature range of −20 °C to 50 °C and improve high temperature stability of the alloy. Also, the addition of Si promoted the formation of the AlFeSi ternary phase, which helped to improve the corrosion resistance of the alloy.

Sign in / Sign up

Export Citation Format

Share Document