Characterization of natural clays from italian deposits with focus on elemental composition and exchange estimated by edx analysis: potential pharmaceutical and cosmetic uses

Purification processes performed on natural clays to select specific clay minerals are complex and expensive and can lead to over-exploitation of some deposits. The present study aimed to examine physicochemical (mineralogy, morphology, size, surface charge, chemical composition, cation exchange capacity [CEC], and pH) and hydration (swelling, wettability, water sorption, and rheological behavior) properties of three native clays from Italian deposits for potential pharmaceutical and cosmetic uses due to the presence of phyllosilicate minerals. Particular emphasis was placed on energy dispersive X-ray (EDX) microanalysis coupled with the ‘cesium method’ to assay clay elemental composition and CEC. One bentonite of volcanic origin (BNT) and two kaolins, one of hydrothermal origin (K-H) and another of lacustrine-fluvial origin (K-L), were evaluated in comparison with a commercial, purified bentonite. The CEC assay revealed the complete substitution of exchangeable cations (Na+ and Ca2+) by Cs+ in BNT samples and CEC values consistent with those of typical smectites (100.64 7.33 meq/100 g). For kaolins, partial substitution of Na+ cations occurred only in the K-L samples because of the interstratified mineral component which has small CEC values (11.13 5.46 meq/100 g for the K-H sample and 14.75 6.58 meq/100 g for the K-L sample). The degree of isomorphous substitution of Al3+ by Mg2+ affected the hydration properties of BNT in terms of swelling, water sorption, and rheology, whereas both of the poorly expandable kaolins exhibited significant water-adsorption properties. The EDX microanalysis has proved to be of considerable interest in terms of providing more information about clay properties in comparison with other commonly used methods and to identify the role played by both chemical and mineralogical composition of natural clays for their appropriate use in pharmaceutical and cosmetic fields

The Impact of Lipid Corona on Rifampicin Intramacrophagic Transport Using Inhaled Solid Lipid Nanoparticles Surface-Decorated with a Mannosylated Surfactant

The mimicking of physiological conditions is crucial for the success of accurate in vitro studies. For inhaled nanoparticles, which are designed for being deposited on alveolar epithelium and taken up by macrophages, it is relevant to investigate the interactions with pulmonary surfactant lining alveoli. As a matter of fact, the formation of a lipid corona layer around the nanoparticles could modulate the cell internalization and the fate of the transported drugs. Based on this concept, the present research focused on the interactions between pulmonary surfactant and Solid Lipid Nanoparticle assemblies (SLNas), loaded with rifampicin, an anti-tuberculosis drug. SLNas were functionalized with a synthesized mannosylated surfactant, both alone and in a blend with sodium taurocholate, to achieve an active targeting to mannose receptors present on alveolar macrophages (AM). Physico-chemical properties of the mannosylated SLNas satisfied the requirements relative to suitable respirability, drug payload, and AM active targeting. Our studies have shown that a lipid corona is formed around SLNas in the presence of Curosurf, a commercial substitute of the natural pulmonary surfactant. The lipid corona promoted an additional resistance to the drug diffusion for SLNas functionalized with the mannosylated surfactant and this improved drug retention within SLNas before AM phagocytosis takes place. Moreover, lipid corona formation did not modify the role of nanoparticle mannosylation towards the specific receptors on MH-S cell membrane

L'analisi di densita' per determinare la purezza di ossidi utilizzati per smalti ceramici

La misura della densità mediante picnometria ad Elio viene testata come metodo rapido di misura del grado di purezza di ossidi utilizzati per la produzione di smalti ceramici

Controllo del contenuto di cristobalite in ceramica sanitaria in funzione della ricottura

Il processo di cottura dei sanitari rappresenta la fase più delicata dell’intero processo di fabbricazione poiché determina quell’insieme di trasformazioni chimicofisiche che conferiscono al prodotto finito le caratteristiche funzionali, tecniche ed estetiche che ne determinano le sue prestazioni.La trasformazione cristobalite alfa → cristobalite beta che si manifesta durantele fasi di consolidamento e densificazione, è caratterizzata da una notevole variazione di volume specifico che determina l’insorgere di microfratture durante il raffreddamento o l’eventuale ricottura dei pezzi.Al fine di comprendere l’effetto del numero di cicli termici di cottura sul contenuto di cristobalite e quindi sui difetti o fratture che si manifestano nei pezzi ceramici è statasa effettuataun’analisi quantitativa delle fasi presenti nei campioni, mediante diffrazione a raggi X

Failure analysis of glazed LAS glass-ceramic containing cerium oxide

In this study a deep investigation of the correlation between microstructure and mechanical properties was performed on glass-ceramic materials containing cerium oxide. The glass-ceramic materials investigated were lithium-aluminum silicate based (LAS), obtained through different thermal cycles from the same parent glass. The mechanical properties were tested on the glass-ceramics with and without the application of a glaze. All the glass-ceramics were characterized by means of scanning electron microscopy (SEM), also in field emission guns geometry (FEG), energy-dispersive spectrometry (EDS), X-Ray diffraction (XRD), and 3-points mechanical flexural strength resistance test. This study has revealed that the microstructure of the glass-ceramic is mainly affected by the heating treatments holding times. The application of a glass coating leads to the formation of cerium oxide crystals at the glaze/glass-ceramic interface. This phenomenon is one of the main principal causes of the mechanical properties failure when a glaze is applied

La calce in architettura e nel restauro: un forum, un libro, un progetto di ricerca scientifica

Il Forum Italiano Calce (www.forumcalce.it) è una Associazione che nasce come luogo di incontro per tutti coloro che studiano, producono e utilizzano la calce in architettura e nel restauro. Il Forum promuove lo sviluppo di esperienze e di conoscenza dell’impiego della calce nel costruito e nel restauro di manufatti di interesse storico, artistico e monumentale attraverso: lo scambio, il confronto e la diffusione di notizie e informazioni sul mondo della calce; l’organizzazione di Congressi, Seminari, Incontri e Corsi; incoraggiando la ricerca scientifica e pratica sulla calce, le malte di calce, le pitture a calce, etc.; sostenendo lo sviluppo di tecniche appropriate a livello industriale e artigianale per la produzione di calce aerea e/o idraulica naturale; favorendo contatti tra gli iscritti che abbiano il desiderio di condividere esperienze e conoscenze sull’argomento. Una delle prime azioni è stata quella di siglare importanti accordi di ricerca scientifica con Università, CNR, Enea e altri centri. Tra gli altri, il Forum Italiano Calce ha recentemente siglato un protocollo di intesa per attività didattiche, di studio e di ricerca con il Dipartimento di Ingegneria dei Materiali e dell’Ambiente dell’Università di Modena e Reggio Emilia.Tra le prime azioni attivate a seguito di questa intesa, l’avvio di uno studio volto a determinare i parametri chimici, fisici e reologici di prova sul grassello di calce che possano fornire elementi di giudizio sufficienti a determinare la qualità del prodotto, che si sta per acquistare e/o impiegare. In particolare verranno definiti i metodi e parametri di prova ed eventuali norme metodologiche di riferimento che saranno successivamente sottoposti all’attenzione delle enti di normativa italiano e europeo, per un auspicabile aggiornamento delle norme che attualmente regolano la produzione e commercializzazione della calce aerea

Deflocculant capability of sodium tripolyphosphates (TTT)

In this paper the deflocculant capability of 3 different tripolyphosphate has been evaluated and interpreted by mineralogical and chemical composition

Il metodo Rietveld nello studio della capacit\ue0 deflocculante di tripolifosfati di sodio

In questo articolo la capacit\ue0 deflocculante di diversi tripolifosfati (TTT) \ue8 messa in corralazione con la loro analisi mineralogica e chimic

Influence of CaO-ZrO2-Al2O3-SiO2 glass-ceramic frits on the technological properties of porcelain stoneware bodies

In the present work, the effect of the addition to a porcelain stoneware body of glass-ceramic frits belonging to the CaO-ZrO2-Al2O3-SiO2 (CZAS, containing 1, 3, 5, 10 mol% of Al2O3) system as replacement of the “state of art” frit belonging to CaO-ZrO2-SiO2 system (CZS) was evaluated. The firing process was performed in a furnace able to complete the thermal cycle in 50 min, in order to simulate the industrial process.Technological properties such as water absorption, firing shrinkage, flexural strength, thermal expansion behaviour were measured. Aesthetical properties were also evaluated. X-ray diffraction and scanning electron microscopy studies were also carried out to analyse the microstructure and the phase compositions of the studied samples. It was found that the sample containing the CZAS frit with 5%mol of Al2O3 shows, in general, the best combination of properties in term of mechanical, physical and aesthetical propertie