Isotherms amorphous ices

N2 as adsorbate, was quite similar to that for N2 on a directly prepared and probably amorphous ice powder [35, 141], On the other hand, N2 adsorption on carbon with increasing thickness of preadsorbed methanol decreased steadily—no limiting isotherm was reached [139]. 

The pressure-density isotherms of various water models in supercooled region, obtained in simulations, can be directly compared with the available experimental isotherms, showing transformations between amorphous ices upon compression." Experimental measured isotherms are unavoidably affected by the transformation kinetics and by the strong hysteresis. These two effects may be reduced by using slow compression rates and higher temperatures, respectively. Therefore, the equilibrium isotherms obtained in simulations we compare with the experimental pressurization curves," which were obtained under the slowest compression rate and at highest temperature. 

Isobaric compression of ice Ih at 165 other phases (e.g., ices II and III) [40] and neither liquid nor amorphous ice can be formed in pure ice experiments. This is the main problem in understanding the relationship between the ice Ih melting line, at 7 > 250K, and the amorphization line, at 7 77K. One way to avoid the transformation of ice Ih to other crystalline forms is to use emulsified ice [13]. In this emulsion, water is mixed with different solutes and cooled at low temperature. The resulting ice emul slon consists of ice Ih domains confined in droplets with radius of 1-10 )U.m. Such small volumes suppress the transformation of ice Ih to other crystalline forms upon isothermal compression and the melting and amorphization lines obtained upon isobaric compression of emulsified ice Ih can be traced at all temperatures [37]. 

The importance of sorption isotherms is generally in the evaluation of the water content in food at which the adverse effects on the food quahty can be minimised. This is usually the moment when other layers are formed around the monomolecular layer of water (vicinal water), which is the instant when the multilayer water arises. Most adverse events in storage of foods with medium and low water content, such as crystallisation of amorphous sugars (e.g. lactose in powdered or condensed milk), agglomeration of powder materials, stickiness or re-crystallisation of water and formation of large crystals in frozen products (e.g. in ice cream) relates to water content, its activity and storage temperature, and are therefore... 

P(3HB-co-8%-3HV) fiber was prepared by one-step-drawing procedure of amorphous fiber with small crystal nuclei at room temperature. Amorphous fibers were obtained by quenching of the melt-spun fibers of P(3HB-co-8%-3HV) into ice water. Isothermal crystallization of amorphous P(3HB-co-8%-3HV) fibers was held in ice water for a certain period to prevent rapid crystallization and to grow small crystal nuclei. One-step-drawing after isothermal crystallization was performed by the stretching machine at room temperature, and then annealed at 60 °C for 30 min in an autoclave for fixing the extended polymer chains. One-step-drawn fibers with isothermal crystallization for 24 h were opaque and maximum total draw ratio was ca. 10 times. 

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