Amorphous systems have attracted considerable attention due to their favorable properties; however, their stability issues still pose a major challenge. The purpose of the present work was to investigate the role of molecular mobility and moisture in the physical stability of a selected pharmaceutical amorphous system. Irbesartan (IBS), a relatively stable glass, was chosen as the model drug, a...

Rodlike capsules consisting of a calcium carbonate core and a crosslinked polystyrene shell were synthesized, and the glass transition temperature (Tg) and characteristic length of the glass transition ξ(Tg) for the thin outer shells were investigated by temperature-modulated differential scanning calorimetry. The shell thickness ranged from 20 to 129 nm. The ratio of the Tg for the outer shell...

An ultrasonic sensor has been developed to monitor photoresist processing in situ during semiconductor manufacturing. Photoresist development, pre-exposure bake, and postexposure bake were monitored for the Shipley 1800 series I-line resists, and the pre-exposure bake of Shipley APEX-E deep-uv (DUV) resist was monitored as well. Development monitoring was achieved by measuring thickness changes...

This study was conducted to investigate the effects of inulin (0, 2.5, 5, and 7.5 %), maltodextrin (0, 15, 20, and 25 %), and different drying processes (oneand two-stage drying) on the morphology and physicochemical properties of regular and instant reduced-fat creamers. The present study showed that the drum-dried creamer containing 0 % maltodextrin and 0 % inulin was fully sticky powder with...

Understanding why the glass transition temperature (Tg) of polymers deviates substantially for the bulk with nanoscale confinement has been a 20-year mystery. Ever since the observation in the mid-1990s that the Tg values of amorphous polymer thin films are different from their bulk values, efforts to understand this behavior have intensified, and the topic remains the subject of intense resear...

Lifetime analysis of positronium annihilating in nanometer voids is used to study the thermal expansion behavior of thin, Si-supported polystyrene films near the glass transition temperature Tg. A reduction in void volume expansion is correlated with a reduction in the apparent Tg as film thickness decreases. Our results can be fitted using a three-layer model incorporating a 50 Å constrained l...

It is frequently assumed that in the limit of vanishing cooling rate, the glass transition phenomenon becomes a thermodynamic transition at a temperature TK. However, with any finite cooling rate, the system falls out of equilibrium at temperatures near Tg(>TK), implying that the very existence of the putative thermodynamic phase transition at TK can be questioned. Recent studies of systems wit...

The relationship between molecular mobility (tauR) of the polar spin probe 3-carboxy-proxyl and water content and temperature was established in pea axes by electron paramagnetic resonance (EPR) and saturation transfer EPR. At room temperature, tauR increased during drying from 10(-11) s at 2.0 g water/g dry weight to 10(-4) s in the dry state. At water contents below 0.07 g water/g dry weight,...

This paper emphasized the significance of the glass transition temperature (Tg) by highliting its applications in drying (hot air and freeze drying) for various food systems such as skim milk powders, rice kernels, starch and sugar products and some freeze-dried products such as strawberries and surimi. The study revealed that the major components of the specified foods (which consist of mixtur...

The influence of both electron beam irradiation and step-crosslinking process on the high abrasion furnace (HAF) carbon black loaded natural rubber (NR) vulcanizates are reported. With irradiation, a higher crosslinking density, ν, thermal conductivity, λ, glass transition temperature, Tg, and decreased specific heat capacity, Cp, have been observed for the irradiated materials as compared with...