@article{10.18756/edn.81.23, title = {{Cupric chloride crystallisation with additives and its applications}}, shorttitle = {{Cupric chloride crystallisation with additives and its applications}}, author = {Barth, Jean-Georges}, journal = {Elemente der Naturwissenschaft}, year = {2004}, volume = {81}, pages = {23--39}, url = {https://dx.doi.org/10.18756/edn.81.23}, doi = {10.18756/edn.81.23}, issn = {p-ISSN 0422-9630}, language = {en}, abstract = {

Les cristaux biog{\'e}niques physiologiques 0u pathologiques constituent des exemples de structures dont la formation est influenc{\'e}e par diverses substances biologiques parmi lesquelles des prot{\'e}ines acides jouent le r{\"o}le d{'}agents de nucl{\'e}ation 011 de modulation de leur morphologie (propri{\'e}t{\'e} de type enzymatique). Il est possible de pr{\'e}parer des cristaux biomim{\'e}tiques en utilisant des copolym{\'e}res synth{\'e}tiques (DHBCS, double hydrophilic block copolymers) qui agissent comme modulateurs de la morphologie de divers min{\'e}raux.

De m{\'e}me, la cristallisation du chlorure cuivrique est modifi{\'e}e par un additif introduit en quantit{\'e} faible voire tr{\'e}s faible dans le milieu. Les additifs (A) sont de toute nature ; les polym{\'e}res naturels ou synth{\'e}tiques exercent la plus grande influence sp{\'e}cifique. Les cristallogrammes obtenus sont h{\'e}t{\'e}rog{\'e}nes dans l{'}espace et le temps. L{'}extraordinaire variabilit{\'e} des morphologies cristallines obtenues fonde le potentiel applicatif du syst{\'e}rne.

Dans le domaine agroalimentaire, {\"a} condition de disposer de r{\'e}f{\'e}rences incontestables, la m{\'e}thode permet de visualiser globalement la qualit{\'e} des produits alimentaires et de donner des apergus que ne permettent pas les r{\'e}sultats de l{'}analyse chimique classique. Les caract{\'e}ristiques d{'}un cristallogramme sont influenc{\'e}es par les constituants chimique majeurs de (A) et par des variations qualitatives et quantitatives m{\'e}me mineures de ses constituants macromol{\'e}culaires, comme le montrent les exp{\'e}riences de traitement du lait en vue de sa conservation et les exp{\'e}riences de d{\'e}gradation physiologique ou enzymatique d{'}un tissu v{\'e}g{\'e}tal.

Dans le domaine m{\'e}dical il est d{\'e}montr{\'e} que les variables cristallographiques sont corr{\'e}l{\'e}es avec des groupes de pathologies et des variations de concentration de prot{\'e}ines sanguines. Elles sont pr{\'e}dictives de l{'}aggravation des pneumoconi0tiques. Par ailleurs les r{\'e}sultats obtenus renforcent l{'}hypoth{\'e}se que la m{\'e}thode pourrait permettre la mise en {\'e}vidence d{'}indicateurs de risque d{'}apparition de pathologies en m{\'e}decine g{\'e}n{\'e}rale (risque d{'}apparition de cancer) ou en m{\'e}decine du travail (diagnostic pr{\'e}coce de maladies professiormelles). La validit{\'e} des hypoth{\'e}ses pr{\'e}dicdves de la m{\'e}thode devra {\'e}tre {\'e}tablie par des {\'e}tudes prospectives appropri{\'e}es.

Les {\'e}l{\'e}ments disponibles permettent de penser que le m{\'e}canisme d{'}ac{\"u}on d{'}un additif sur la cristallisation du chlorure cuivrique proc{\'e}de des m{\'e}mes m{\'e}canismes que ceux d{\'e}crits pour d{'}autres syst{\'e}mes.

}, annote = {

Biogenic crystals formed under conditions of health or disease are examples of structures whose formation is influenced by a variety of biological substances. Amongst these, acidic proteins play a part in nucleation or modulation of crystal morphology (enzymatic type of property). It is possible to prepare biomimetic crystals using synthetic copolymers (DHBCS{\quotesinglbase} double hydrophilic block copolymers) which act as modulators of the morphology of an assortment of minerals. In the same way copper chloride crystallisation is modified by an additive introduced in small to very small quantities into the medium. Additives (A) are of every kind; natural or synthetic polymers exert the greatest specific influence. The crystallograms obtained are heterogeneous with respect to space and time. The remarkable variability of crystal morphologies forms the basis of the system{'}s potential for application. In the agrifood field, provided that reliable reference material is available, the method allows overall visualisation of food product quality and gives indications that chemical analysis cannot. The characteristics of a crystallogram are influenced by the major chemical constituents of the additive and by the minor qualitative and quantitative variations of its macromolecules. This is shown by the results of both the treatment of milk for its preservation and the physiological or enzymatic degradation of plant tissue.

In the field of medicine it has been demonstrated that crystallographic variables are correlated with groups of pathologies and with variations in the concentration of blood ptoteins. The variables are predictive of a worsening of pneumoconiosis. In another respect, the results obtained reinforce the hypothesis that the method enables visualisation of the risk indicators of pathologies manifesting in general practice (risk of cancer appearing) or occupational health (early diagnosis of occupational diseases). The validity of the hypothesis regarding the method{'}s predictive value would have to be established through appropriate prospective studies. The available data support the view that the mechanism of action of an additive on the crystallisation of copper chloride proceeds according to the same mechanisms as those described for other systems.
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