Different quantities of additives (sodium chloride and oxalic acid) and antisolvent (ethanol) were used in order to define their influence on crystallization of glycine from aqueous solutions. The solubility curves were determined for all process conditions but the nucleation points only for the initial concentration of glycine. The obtained results showed that both the quantity and type of the additive affect the solubility curves, the metastable zone width as well as the granulometric characteristics of crystals (aspect ratio, external shape, and the crystal size distribution). X-ray analysis confirmed occurrences of c-glycine by adding sodium chloride and oxalic acid, regardless of the added mass while the a-polymorphs were achieved by adding ethanol. IntroductionCrystallization is one of the most important methods to obtain pure solid crystalline compounds. In different industries, the most important requirements a crystallized solid-state product has to fulfil are its phase or polymorph stability with respect to thermodynamics and kinetics during its storage life and growth. Additionally, the size distribution determines the product solid-state properties such as separation, flowability, compaction, dissolution, and packing [1].Here, cooling crystallization of glycine from solution in the presence of different additives is investigated. Glycine was chosen as the model system because its solution and solid chemistries have been well studied and characterized and due to the properties of glycine crystals to be crystallized in three different polymorphs. Glycine exists in three crystalline modifications: a-, ß-, and c-forms with different relative stabilities and structures. It is well-known that the least stable form of glycine is the ß-form which transforms readily to the a-or c-form in a humid environment. Although, the a-form is quite stable at room temperature but c-glycine is thermodynamically the most stable form and has some special properties which are important for the pharmaceutical industry (nonlinear optical materials) [2].The crucial factors which yield different polymorphs are the thermodynamic variables (temperature, pressure, and concentration) and the process variables (agitation, supersaturation, seeding, cooling rate, pH values, and additives) [3]. Foreign substances present in the medium, used for the growth of a variety of various substances, have long been recognized to have a profound influence on the external appearance of crystals. Understanding the conditions of occurrence of the polymorphic forms and their transformations from one form into the other would be of great interest and useful for pharmaceutical applications [4].ß-Glycine can be produced under high-supersaturation conditions [5] and is usually crystallized using methanol, ethanol, 2-propanol, or acetone as antisolvent [6][7][8][9]. Pure aqueous solutions lead to the a-form, and the c-form occurs from aqueous solution only in the presence of selected impurities (sodium chloride, sodium hydroxide, sodium fluoride, sodium ni...

The formation of hollow crystalline needles by means of a solvent-mediated phase transformation takes place during the dehydration of hydrate crystals in methanol into hollow needle-shaped anhydrate crystals. Here, a special way of achieving needle growth is presented. When a saturated aqueous solution of sodium-2-ketogulonate is dropped into methanol, a simultaneous nucleation of monohydrate crystals and anhydrate needles takes place in the alcohol. It was proven by scanning electron microscope images that these needles are hollow. By means of the variation of the production method, it is for the first time possible to observe the needle growth in a more detailed manner, and to show that the nucleation can take place at impurities and surface roughnesses. The method helped to discuss and to deepen the understanding of the growth mechanism of the hollow crystalline needles.

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Hollow crystalline glucose anhydrate needles are produced based on a technique to produce hollow crystal needles by phase transformation of solvate crystals into non-solvates. The fascinating characteristic of the glucose anhydrate needles is the possibility of closing them by a simple drying process. This creates great potential for future applications as a container system, e.g., for pharmaceutical substances. The hollowness of the needles has already been proven, but the filling of the needles has not been investigated. Due to the lack of a direct method to demonstrate the possibility of filling the needles, two indirect methods are presented to demonstrate a successful technique to enclose substances in these needles. On the one hand, the filling is proven by fluorescence microscopy of glucose anhydrate needles with enclosed rhodamine 6G. Here it is possible to visualize the fluorescence dye by observation of the broken needles. On the other hand, the concentration of included ibuprofen is examined by the means of UV spectroscopic measurements. A significant concentration of the enclosed drug is detected following the extraction out of the needle interior.

In this paper I will argue that liberal multiculturalism is neither a necessary nor a convincing extension of liberalism. In evaluating the two main strands of liberal multiculturalism, I will first analyse the approaches of Charles Taylor and Bhikhu Parekh as the main proponents of the version that focuses on the cultures themselves and raises the issue of the value of cultures in connection with public discourse. I will then turn to Amy Gutmann and Will Kymlicka as liberal multiculturalists who use the liberal norm of individual equality as a starting point. I will show that the arguments adduced in favour of liberal multiculturalism fail, due to the following shortcomings. Taylor’s approach is underspecified with respect to the relationship between the process of evaluating cultures and its outcome. Gutmann’s theory fails to bridge the gaps between the individual, cultural belonging and positive duties of the state. Parekh’s and Kymlicka’s theories lead back to liberalism. I conclude that the idea of cultural difference has little of substance to add to the liberal view of social justice.