scholarly journals Organo-Soluble Semi-Alicyclic Polyimides Derived from Substituted-Tetralin Dianhydrides and Aromatic Diamines: Synthesis, Characterization and Potential Applications as Alignment Layer for TFT-LCDs

10.5772/51182 ◽  
2013 ◽  
Author(s):  
Jin-gang Liu ◽  
Yuan-zheng Guo ◽  
Hai-xia Yang ◽  
Shi-yong Yang
Keyword(s):  
Aromatic Diamines ◽  
Alignment Layer ◽  
Potential Applications

The effect of plasticization on the properties of poly(urethaneureas) based on oligoether diols, 2,4-toluenediisocyanate, and aromatic diamines

2018 ◽  
Vol 51 (4) ◽  
pp. 337-358 ◽  
Author(s):  
Vasiliy Tereshatov ◽  
Marina Makarova ◽  
Valeriy Senichev ◽  
Zhanna Vnutskikh ◽  
Tamara Oshchepkova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Arctic Climate ◽  
The Arctic ◽  
Aromatic Diamines ◽  
Plasticization Effect ◽  
Soft Segments ◽  
Potential Applications ◽  
Partial Crystallization ◽  
First Time

Segmented poly(urethaneureas) (SPUUs) modified with low glass transition temperature chemically inert liquids are of interest due to their controllable properties and potential applications under various environmental conditions. Investigation into the influence of plasticizers on the properties of SPUUs based on oligotetramethyleneoxide diol (polytetramethyleneoxide), oligopropyleneoxide diol (polypropyleneoxide), 2,4-toluenediisocyanate, Ethacure-300, and methylene-bis- o-chloroaniline was conducted. Partial crystallization of polytetramethyleneoxide segments was identified during cooling of some SPUU samples plasticized by di-(2-ethylhexyl)sebacate (DEHS) and tributyl phosphate. Polypropyleneoxide segments did not crystallize under the same conditions. A low crystallization temperature for the amorphous component of the polymer matrix in SPUU (−100°C to 103°C) was attained at a molecular mass ( Mn) of soft segments equal to 2000 g mol−1 and a DEHS concentration equal to 40–45%. A relationship between the mechanical properties of plasticized SPUU, microphase segregation, and dilution of the polymer matrix was found. For the first time, the effect of dilution with plasticizer on the strength of elastomers was considered. The plasticization effect on the mechanical properties of SPUU was investigated in the temperature diapason from 50°C to −70°C. The results of these investigations can be used in various technologies including the design of SPUUs with high elastic properties at temperatures as low as −70°C, typical of extreme conditions of the Arctic climate.

scholarly journals Preparation and Properties of Inherently Black Polyimide Films with Extremely Low Coefficients of Thermal Expansion and Potential Applications for Black Flexible Copper Clad Laminates

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 576 ◽  
Author(s):  
Yao-yao Tan ◽  
Yan Zhang ◽  
Gang-lan Jiang ◽  
Xin-xin Zhi ◽  
Xiao Xiao ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Dimensional Stability ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Optical Transmittance ◽  
Molecular Structures ◽  
Molar Ratio ◽  
Optical Parameters ◽  
Aromatic Diamines ◽  
Potential Applications

In the current work, a series of black polyimide (PI) films with excellent thermal and dimensional stability at elevated temperatures were successfully developed. For this purpose, two aromatic diamines including 4,4′-iminodianline (NDA) and 2-(4-aminophenyl)-5- aminobenzimidazole (APBI) were copolymerized with pyromellitic dianhydride (PMDA) to afford PIs containing imino groups (–NH–) in the molecular structures. The referenced PI film, PI-ref, was simultaneously prepared from PMDA and 4,4′-oxydianiline (ODA). The introduction of imino groups endowed the PI films with excellent blackness and opaqueness with the optical transmittance lower than 2% at the wavelength of 600 nm at a thickness of 25 μm and lightness (L*) below 10 for the CIE (Commission International Eclairage) Lab optical parameters. Meanwhile, the introduction of rigid benzimidazole units apparently improved the thermal and dimensional stability of the PI films. The PI-d film based on PMDA and mixed diamines (NDA:APBI = 70:30, molar ratio) showed a glass transition temperature (Tg) of 445.5 °C and a coefficient of thermal expansion (CTE) of 8.9 × 10−6/K in the temperature range of 50 to 250 °C, respectively. It is obviously superior to those of the PI-a (PMDA-NDA, Tg = 431.6 °C; CTE = 18.8 × 10−6/K) and PI-ref (PMDA-ODA, Tg = 418.8 °C; CTE: 29.5 × 10−6/K) films.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Fabrication and characterization - by High Resolution Electron Microscopy and atom probe microanalysis - of Co-based metallic multilayer films

1990 ◽  
Vol 48 (4) ◽  
pp. 772-773
Author(s):  
Amanda K. Petford-Long ◽  
A. Cerezo ◽  
M.G. Hetherington
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Atom Probe ◽  
Multilayer Films ◽  
Interface Roughness ◽  
Probe Field ◽  
Resolution Electron ◽  
Potential Applications ◽  
Field Ion Microscope

The fabrication of multilayer films (MLF) with layer thicknesses down to one monolayer has led to the development of materials with unique properties not found in bulk materials. The properties of interest depend critically on the structure and composition of the films, with the interfacial regions between the layers being of particular importance. There are a number of magnetic MLF systems based on Co, several of which have potential applications as perpendicular magnetic (e.g Co/Cr) or magneto-optic (e.g. Co/Pt) recording media. Of particular concern are the effects of parameters such as crystallographic texture and interface roughness, which are determined by the fabrication conditions, on magnetic properties and structure.In this study we have fabricated Co-based MLF by UHV thermal evaporation in the prechamber of an atom probe field-ion microscope (AP). The multilayers were deposited simultaneously onto cobalt field-ion specimens (for AP and position-sensitive atom probe (POSAP) microanalysis without exposure to atmosphere) and onto the flat (001) surface of oxidised silicon wafers (for subsequent study in cross-section using high-resolution electron microscopy (HREM) in a JEOL 4000EX. Deposi-tion was from W filaments loaded with material in the form of wire (Co, Fe, Ni, Pt and Au) or flakes (Cr). The base pressure in the chamber was around 8×10−8 torr during deposition with a typical deposition rate of 0.05 - 0.2nm/s.

Progress and perspectives on halide lithium conductors for all-solid-state lithium batteries

2020 ◽  
Vol 13 (5) ◽  
pp. 1429-1461 ◽  
Author(s):  
Xiaona Li ◽  
Jianwen Liang ◽  
Xiaofei Yang ◽  
Keegan R. Adair ◽  
Changhong Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Solid State ◽  
Lithium Batteries ◽  
Electrochemical Stability ◽  
Superionic Conductors ◽  
Fundamental Understanding ◽  
Potential Applications ◽  
Synthesis Routes

This review focuses on fundamental understanding, various synthesis routes, chemical/electrochemical stability of halide-based lithium superionic conductors, and their potential applications in energy storage as well as related challenges.

Porphyrin-functionalized coordination star polymers and their potential applications in photodynamic therapy

2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Self Assembly ◽  
Star Polymers ◽  
New Family ◽  
Potential Applications

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.

A peek in the micro-sized world: a review of design principles, engineering tools, and applications of engineered microbial community

2020 ◽  
Vol 48 (2) ◽  
pp. 399-409
Author(s):  
Baizhen Gao ◽  
Rushant Sabnis ◽  
Tommaso Costantini ◽  
Robert Jinkerson ◽  
Qing Sun
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Environmental Remediation ◽  
Real Life ◽  
Design Principles ◽  
Microbial Interactions ◽  
Potential Applications ◽  
New Gene ◽  
Global Biogeochemical Cycles ◽  
Synthetic Microbial Communities

Microbial communities drive diverse processes that impact nearly everything on this planet, from global biogeochemical cycles to human health. Harnessing the power of these microorganisms could provide solutions to many of the challenges that face society. However, naturally occurring microbial communities are not optimized for anthropogenic use. An emerging area of research is focusing on engineering synthetic microbial communities to carry out predefined functions. Microbial community engineers are applying design principles like top-down and bottom-up approaches to create synthetic microbial communities having a myriad of real-life applications in health care, disease prevention, and environmental remediation. Multiple genetic engineering tools and delivery approaches can be used to ‘knock-in' new gene functions into microbial communities. A systematic study of the microbial interactions, community assembling principles, and engineering tools are necessary for us to understand the microbial community and to better utilize them. Continued analysis and effort are required to further the current and potential applications of synthetic microbial communities.

Dynamic Assessment Language Tasks and the Prediction of Performance on Year-End Language Skills in Preschool Dual Language Learners

2020 ◽  
Vol 29 (3) ◽  
pp. 1226-1240
Author(s):  
Janet L. Patterson ◽  
Barbara L. Rodríguez ◽  
Philip S. Dale
Keyword(s):  
Head Start ◽  
Language Learners ◽  
Language Impairment ◽  
Dual Language ◽  
Dynamic Assessment ◽  
Dual Language Learners ◽  
Achievement Testing ◽  
Potential Applications ◽  
Language Screening ◽  
Relationship Of

Purpose Early identification is a key element for accessing appropriate services for preschool children with language impairment. However, there is a high risk of misidentifying typically developing dual language learners as having language impairment if inappropriate tools designed for monolingual children are used. In this study of children with bilingual exposure, we explored performance on brief dynamic assessment (DA) language tasks using graduated prompting because this approach has potential applications for screening. We asked if children's performance on DA language tasks earlier in the year was related to their performance on a year-end language achievement measure. Method Twenty 4-year-old children from Spanish-speaking homes attending Head Start preschools in the southwestern United States completed three DA graduated prompting language tasks 3–6 months prior to the Head Start preschools' year-end achievement testing. The DA tasks, Novel Adjective Learning, Similarities in Function, and Prediction, were administered in Spanish, but correct responses in English or Spanish were accepted. The year-end achievement measure, the Learning Accomplishment Profile–Third Edition (LAP3), was administered by the children's Head Start teachers, who also credited correct responses in either language. Results Children's performance on two of the three DA language tasks was significantly and positively related to year-end LAP3 language scores, and there was a moderate and significant relationship for one of the DA tasks, even when controlling for age and initial LAP3 scores. Conclusions Although the relationship of performance on DA with year-end performance varies across tasks, the findings indicate potential for using a graduated prompting approach to language screening with young dual language learners. Further research is needed to select the best tasks for administration in a graduated prompting framework and determine accuracy of identification of language impairment.

Hybrid Telecoaching for Corporate Speech Training and Potential Applications to Clinical Practice

2019 ◽  
Vol 4 (2) ◽  
pp. 322-324
Author(s):  
Thomas F. Burke
Keyword(s):  
Clinical Practice ◽  
Engineering Teams ◽  
Corporate Strategies ◽  
Corporate Speech ◽  
Phone Calls ◽  
Future Clinical Practice ◽  
Fortune 100 ◽  
Potential Applications ◽  
Language Pathology ◽  
Development Engineering

Purpose The purpose of this article was to describe a model for “hybrid speech telecoaching” developed for a Fortune 100 organization and offer a “thought starter” on how clinicians might think of applying these corporate strategies within future clinical practice. Conclusion The author contends in this article that corporate telecommunications and best practices gleaned from software development engineering teams can lend credibility to e-mail, messaging apps, phone calls, or other emerging technology as viable means of hybrid telepractice delivery models and offer ideas about the future of more scalable speech-language pathology services.

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