Amorphous glasses recent developments

New classes of hole-blocking amorphous molecular materials have recently been developed, which include the families of triarylbenzenes and triarylboranes (Table 7.4). These compounds readily form amorphous glasses with well-defined Tgs and possess weakly electron-accepting properties. These hole-blocking materials enabled fabrication of high-performance blue- and blue-violet-emitting OLEDs using a-NPD, p-TTA and TPD as emitters. The performance of some devices is summarized in Table 7.5. 

The relatively recent development of contactless processing, such as aerodynanuc [32], aero-acoustic [42], and electrostatic [38] levitation techniques has enabled the structural determination of amorphous materials that were previously experimentally challenging or even unachievable. Levitation methods have been used for both in situ structural measurements [9, 23] and ex situ for atypical sample preparation this includes sample purification [43, 47] and single crystal growth [6], but is perhaps most often applied to the fabrication of new glasses which are unobtainable by other methods. 

Highly densified vitreous silica may be an example of an amorphous polymorph. Recently the amorphous to amorphous (pressure induced high-density) reversible phase transition has received much attention in connection with the development of bulk metal glasses such as La68Al2oCu2oC 02 [Liu and Hong, 2007[. Amorphous fluid phases are also possible. 

Chapter 3 provides a brief review of recent developments in areas of amorphous polymer blends. Differential mixing, chain dynamics, and glass transition properties for individual polymer components in miscible binary blends, as well as new methods to experimentally acquire such information, are considered. Miscible blend dynamics and length scales of mixing of amorphous polymer blends are discussed. Amorphous biopolymer blends involving polymers obtained from renewable feedstocks is also briefly reviewed. 

A major development in fluoroplastks is the recent small scale production of Teflon AF, a noncrystaUme (amorphous) fluorocarbon polymer with a high glass transition temperature (240 °C) This optically transparent TFE copolymer is soluble m certan fluorocabons and has the same chemical and oxidative stability as crystallme TFE homopolymers [5]... 

An enormous amount of work, part of which has been recently reviewed [28,29], has been reported regarding the immobilisation of DNA molecules in high concentration layers, mostly referring to hard surfaces (e.g., glass or mica) and mainly for practical devices and AFM experiments. However, the rapid development of, and increasing demand for, DNA-based microdevices both push for lower cost, easily processable materials, and towards disposable devices. As polymers seem to be the logical choice, the resulting DNA layers will almost certainly be amorphous. 

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