Self-detachment

Glass-Transition Temperature and Self-Detaching of Maltodextrin Films Effect of Molecular Weight and Sucrose Addition... 

Collares et al. (2004), studying the drying of gum Arabic and malfodexfrin (DE 10) on a glass surface, observed that self-detachment occurred when the moisture content of fhe film reached values related to the glass-transition... 

The results obtained for the detachment of the maltodextrins RD-111 (Figure 21.4a) and MOR-REX 1914 (Figure 21.5b) confirmed the behavior found by Collares et al. (2004) for maltodextrin MOR-REX 1910. The conditions for the self-detachment of maltodextrins with different A4 followed the same pattern as the glass-transition curve of the corresponding material. The experimental points, however, are located underneath the curve, probably due to an overdrying during the sample collection procedures. For the maltodextrins RD-111 and MOR-REX 1910, self-detachment occurred in the temperature range of 15°C below the Tg curve, and for the maltodextrin MOR-REX 1914, the limits of temperature was 20°C. 

Temperatures and moisture contents of dried films of maltodextrin at the moment of self-detachment from an inert solid (ordinary glass slide). 

Glass-transition curves for maltodextrins with different molecular weights (a) 4759 g/mol, DE — 04 and (b) 957.5 g/mol, DE — 19, and experimental points at the moment of self-detachment of the film from a solid surface. 

The effect of mixtures on the detachment conditions was also evaluated by dr)dng pastes made by a mixture of maltodextrin MOR-REX 1910 and sucrose, with a total solid content of 61.5%, but with increasing amount of sucrose (5, 10, and 15% sucrose, dry weight basis (dwb)). Results in Figure 21.3 indicate that for a defined drying temperature, the moisture content at the moment of self-detachment of the dried film decreased with the increase in sucrose addition. Thus the addition of sucrose made the detachment of dried films of maltodextrin from an inert solid surface during the drying process more difficult. The larger the amount of sucrose added. 

Glass-transition curves and self-detachment conditions for aqueous solutions of maltodextrin MOR-REX 1910 (a) maltodextrin + 5% sucrose, (b) maltodextrin + 10% sucrose, and (c) maltodextrin -I-15% sucrose. 

In Figure 21.5, the self-detachment conditions for aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose at 5, 10, and 15% (dwb) are compared with the glass-transition curves calculated using the expanded Gordon-Taylor model (Roos, 1993). The self-detachment of the dried films of aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose followed the same pattern of decreasing moisture content of the material with an increase in temperature as observed with the glass-transition data. This process occurred in a temperature range of 20°C below Tg, for 5,10, and 15% sucrose concentrations, as was observed by Collares et al. (2004) for maltodextrin MOR-REX 1910 without the addition of sucrose. 

Koyama H, Fauchet PM (2000) Laser-induced thermal effects on the optical properties of freestanding porous silicon films. J Appl Phys 87(4) 1788-1794 Kumar N et al (2014) Self-detachment of free-standing porous silicon membranes in moderately doped n-type silicon. Appl Phys A 116 251-257... 

In systems of LP the dynamic response to a temperature quench is characterized by a different mechanism, namely monomer-mediated equilibrium polymerization (MMEP) in which only single monomers may participate in the mass exchange. For this no analytic solution, even in terms of MFA, seems to exist yet [70]. Monomer-mediated equilibrium polymerization (MMEP) is typical of systems like poly(a-methylstyrene) [5-7] in which a reaction proceeds by the addition or removal of a single monomer at the active end of a polymer chain after a radical initiator has been added to the system so as to start the polymerization. The attachment/detachment of single monomers at chain ends is believed to be the mechanism of equilibrium polymerization also for certain liquid sulphur systems [8] as well as for self-assembled aggregates of certain dyes [9] where chain ends are thermally activated radicals with no initiators needed. 

A third reason is that Gibbs made no effort to promote or popularize his results. He seems to have been a solitary, self-contained, and self-sufficient thinker, confident in his ability, who worked at his own unhurried pace, neither needing nor wanting feedback from others. An attitude of detachment from the work of his students plus his own solitary habit of work is undoubtedly responsible for the fact that Gibbs founded no school or group of students to develop his ideas and exploit his discoveries. 

For mechanical assemblies using screws can be detached indefinitely, with the exception of self-tapping screws, which can be loosened and retightened only a limited number of times. The best guideline for the designer is to prefer any assembly design that converts... 

The burning mechanism of composite propellants differs from that described above. There is no exothermic reaction which can lead to a self-sustaining fizz zone. Instead, the first process appears to be the softening and breakdown of the organic binder/fuel which surrounds the ammonium perchlorate particles. Particles of propellant become detached and enter the flame. The binder is pyrolysed and the ammonium perchlorate broken down, initially to ammonia and perchloric acid. The main chemical reaction is thus in the gas phase, between the initial dissociation products. 

Without impartial controls, investigators even when acting in good faith, too often and too quickly (self-serving) find probable cause, because of the competitive enterprise and predisposition of investigating crime. Therefore, it is the neutral and detached magistrate who narrowly defines the permissible scope of a search before it occurs [16]. 

PCP and ketamine are dissociative anesthetics. They can induce analgesia without loss of consciousness. The individual appears awake but will not remember the experience, and vital signs such as respiration and heart rate are not impaired. The drugs distort perceptions of sight and sound, and produce feelings of detachment and dissociation from the environment and self. Persons abusing PCP exhibit very bizarre behavior and may become violent. 

The basic tenet is that you manage that from which you are detached you are managed by that with which you are attached or identified. You must remember that you are neither your thoughts, nor your beliefs nor your feelings or behaviour you are the manager of all these. However, if you identify with them you will find It almost impossible to ter them any effort to do so would Imply attacking your self-identity. (p. 100)... 

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