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The most common reactive material used for the construction of a permeable reactive barrier (PRB) is zero valent iron (ZVI), however, its processing can generate corrosive effects that reduce the efficiency of the barrier. The present study makes a major contribution to understanding new reactive materials as natural and synthetic, easy to obtain, economical and environmentally friendly as possible substitutes for the traditional ZHV to be used as filters in the removal of three transition metals (Zn, Cu, Cd). To assess the ability to remove these pollutants, a series of batch and column tests were carried out at laboratory scale with these materials. Through BACH tests, four of seven substances with a removal percentage higher than 99% were prioritized (cabuya, natural clinoptilolite zeolites, sodium mordenite and mordenite). From this group of substances, column tests were performed where it is evidenced that cabuya fiber presents the lowest absorption time (≈189 h) while natural zeolite mordenite shows the highest time (≈833 h). The latter being the best option for the PRB design. The experimental values were also reproduced by the RETRASO code; through this program, the trend between the observed and simulated values with respect to the best reactive substance was corroborated., Special acknowledgment to Carmine Fallico and Adalgisa Tavolaro for coordinating the technical activities between the Escuela Superior de Chimborazo (ESPOCH), the Universidad Técnica de Ambato (UTA), the Universidad de Calabria (UNICAL), the Consiglio Nazionale di Ricerca (CNR-ITM) and the Universidad Técnica de Cataluña.

Porous carbon materials are currently subjected to strong research efforts mainly due to their excellent performances in energy storage devices. A sustainable process to obtain them is hydrothermal carbonization (HTC), in which the decomposition of biomass precursors generates solid products called hydrochars, together with liquid and gaseous products. Hydrochars have a high C content and are rich with oxygen-containing functional groups, which is important for subsequent activation. Orange pomace and orange peels are considered wastes and then have been investigated as possible feedstocks for hydrochars production. On the contrary, orange juice was treated by HTC only to obtain carbon quantum dots. In the present study, pure orange juice was hydrothermally carbonized and the resulting hydrochar was filtered and washed, and graphitized/activated by KOH in nitrogen atmosphere at 800 &deg, C. The resulting material was studied by transmission and scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen sorption isotherms. We found porous microspheres with some degree of graphitization and high nitrogen content, a specific surface of 1725 m2/g, and a pore size distribution that make them good candidates for supercapacitor electrodes.

In this study, we propose a novel approach to prepare few-layer graphene (FLG) dispersions, which is realized by exfoliating natural graphite flakes in a surfactant aqueous solution under hydrothermal treatment and liquid-phase exfoliation. In order to obtain stable and well-dispersed FLG dispersions, pristine graphite is hydrothermally expanded in a hexadecyltrimethylammonium bromide (CTAB) aqueous solution at 180 °C for 15 h, followed by sonication up to 3 h. In comparison to long-time sonication methods, the present method is significantly efficient, and most importantly, does not involve the use of an oxidizing agent and hazardous media, which will make it more competent in the scalable production of graphene.

This work is focused on the response of two invasive phenotypes of human breast cancer cells, MCF-7 and MDA-MB-231, grown on synthesized zeolite scaffolds in order to study the influence of those biomaterials in controlled conditions with and without anti-tumoral drug treatments. Our research was directed to the use of doxorubicin (DOX) and bergapten (5-MOP). The former is broadly considered the most active single agent available for the treatment of breast cancer, the second is a natural psoralen with an apoptotic effect. The results indicate that both drugs inhibit the cell viability of all cell lines grown on all zeolite scaffolds and that all Pure Zeolite Membranes are more responsive with respect to all Mixed Matrix Membranes. Moreover, the results after treatment with DOX at a concentration of 7.4 ?M for 24 h, show that the expression of the matrix metalloproteinases (MMP-2 and MMP-9) is greatly reduced in both cell lines, especially in those adherent on Pure Zeolite Scaffolds.

We present a study of adsorption of Cresyl Violet (CV) in aqueous solution on sonicated Graphite Oxide (sGO). For comparison, we also show adsorption results of Methylene Blue (MB) and Acridine Orange (AO) performed in the same conditions. The adsorbent was synthesized by the Tour's method followed by washing in water and ethanol and sonication, without any reduction, and studied by Raman, IR, UV-Vis, SEM and TEM techniques. Our results show that adsorption fits the pseudosecond order model for the three dyes, and that the adsorption quantity for CV is 125.0 mg g-1, while for MB and AO is 123.3 and 94.6 mg g-1 respectively.

A series of experimental batch tests has been carried out with the aim of improving the knowledge of fundamental processes related to the fate and behavior of heavy metals that can be of environmental concern in groundwater. The analysis of contaminants (i.e., Cu, Zn, Cd and Pb) dynamics in different environmental compartments is specifically addressed by comparing the removal efficiencies of different types of reactive materials, three natural (i.e., vegetal fibers, natural limestone and natural zeolite) and one synthetic (i.e., synthetic zeolite). Results stemming from these reactive media has been compared with the outcomes related to the same test performed using zero valent iron which is the reactant usually employed for heavy metals remediation. All tested reactants exhibited important removal percentages, even larger than 90% in most cases, achieved in a contact time ranging between about 12 h and slightly longer than a day (i.e., 30 h). Maximum adsorption percentages are observed for pH ranging between 4 and 8 for all tested materials and contaminants. Our findings provided relevant evidence, to both researchers and technicians, on the competitiveness of the explored alternative mediums with respect to the classical reactants usually employed for heavy metals remediation.

The growing contamination of groundwater requires increasingly remediation. Among the different reclamation techniques of contaminated aquifers, recourse is frequently made to permeable reactive barriers (PRB). To build such barriers Zero Valent Iron (ZVI) is commonly used, which shows a good reactivity towards the most part of the heavy metals. However, owing to economic reasons, and to some problems that this substance produces, reactive substances usable in alternative to zero valent iron are constantly being researched. The present study takes into account the fibers of a vegetable substance, the cabuya, investigating its capacity to retain heavy metals. Specifically, among these, Copper (Cu), Zinc (Zn), Lead (Pb) and Cadmium (Cd) were considered. The capacity of the fibers of cabuya to absorb heavy metals was verified in the laboratory, at first by batch tests and later by appropriate column tests. The same tests were carried out using also Zero Valent Iron. The results obtained for the cabuya vegetable fibers, showed a very high adsorption capacity of heavy metals and resulted very comparable to that of ZVI, without, however, showing the negative aspects of the latter. Some comparisons were also carried out with broom fibers, investigated in a previous study.

LTL, MEL, MFI, LTA, FAU pure and hybrid zeolite membranes were synthesized and applied to in vitro cell cultures. These membranes have been used in inorganic cell/scaffold constructs having different physicochemical characteristics such as frameworks, hydrophilicity, crystal size, chemical composition, acid-base properties (Point of Zero Charge, PZC) and surface morphology. We have selected the MCF-7 human breast cancer cell line as model tumor cell line. Because the control of cell interactions, as the adhesion, proliferation, remodelling and mobility, is important for differentiation and progression of tumors, this work focused on response of cancer cells adhered and grown on synthesized zeolite surfaces in order to study the influence of these scaffolds in controlled conditions. This study showed that all the synthesized zeolite membranes are excellent scaffolds because they are very selective materials to support the adhesion and growth of neoplastic cells. In addition, we evaluated the applicability of zeolite pure and hybrid membranes as carrier for selective adsorption and the delivery of two antineoplastic drugs: doxorubicin (DOX) and bergapten (5-MOP). FESEM, FTIR-ATR, XRD, AFM, Point of Zero Charge (PZC) and contact angle analyses have characterized all scaffolds. Cell adhesion, viability and morphology were measured by count, MTT assay and FESEM microphotography analysis, at various incubation times from seeding and drug treatments.

The novelty of the present work lies in the association of the synthesis of zeolite membranes with the adhesion of the cells. The skill to grow isolated human cells outside of the body has led to advances in fields ranging from the materials science to tissue engineering and nanomedicine [1]. Recently, methods to step up human cells from progenitor and stem cells ex vivo have been developed and this approach holds out great therapeutic promise. A huge effort has been directed at the development of synthetic substrates that can provide biomimetic signals to cells, encouraging them to attach and behave as they would in their natural environment [2-4]. Evaluation of novel materials such as components of substrates for cell growth remains an important research goal [5,6]. Page 2 of 16 Accepted Manuscript ?The adhesion and the subsequent cell activities (spreading, focal adhesion, migration, and proliferation) are highly sensitive to the surface chemistry and its physical environment including the chemical composition (atom ratio, Bro?nsted's and Lewis's acidity, hydrophobic/hydrophilic properties), structure, porosity, crystallinity of the materials, morphology and topography of the surfaces to which cells adhere [7-10]. For many years polymeric membranes have attracted the interest of researchers for their potentialities [11,12]. However, they are affected the same drawbacks that up to now have limited the wide utilization of these materials [13]. Indeed, the accessibility to using an inorganic material that marries specific performances of membranes and properties of zeolites has an edge over the other scaffolds [14]. Their peculiar physicochemical characteristics and the relatively simple possibility of preparing highly reproducible large-area zeolite membranes has placed these inorganic materials to the forefront of scientific interest correlated to the preparation of designed and synthesized materials for innovative applications in the past decade [15]. For years, zeolite crystals have been used in various technological fields of great industrial interest such as catalysts, ion-exchangers, and adsorbents in chromatographic applications. Today, the preparation of crystalline inter-grown zeolite membranes plays a central role in many new applicative fields such as catalytic zeolite membrane reactors, gas mixture separations, and pervaporation of aqueous solutions and drug delivery [16,17]. The design, synthesis and selection of inorganic materials useful as functional scaffolds for cell adhesion is a complex question based both on the understanding of the chemical behavior of the individual cells and materials, and on their interactions. Since it is well known that initial interactions of foreign materials with the living cells begins with adsorption of proteins onto non-living surfaces, to Page 3 of 16 Accepted Manuscript ?understand how the physicochemical parameters of these innovative zeolite materials can influence biological performances and, then, to rationalize their behaviour with regard to both desired and undesired effects, we have just reported the immobilization of proteins like Bovine Serum Albumin and cytochrome c on zeolite crystals and membranes [18,19]. In this study, pure structure zeolite membranes have been synthesized and utilized, without surface functionalization, for the adhesion and growing of fibroblasts.

In few years, graphene has become a revolutionary material, leading not only to applications in various fields such as electronics, medicine and environment, but also to the production of new types of 2D materials. In this work, Liquid Phase Exfoliation (LPE) was applied to natural graphite by brief sonication or mixer treatment in suitable solvents, in order to produce Few Layers Graphene (FLG) suspensions. Additionally, zeolite 4A (Z4A) was added during the production of FLG flakes-based inks, with the aim of aiding the exfoliation process. Conductive films were obtained by drop casting three types of suspensions over Al2O3 substrates with interdigitated electrodes, with total channel surface of 1.39 mm2. The morphology characterization resulted in the verification of the presence of thin self-assembled flakes. Raman studies gave evidence of 4 to 10 layers graphene flakes. Electrical measurements were performed to state the Low-Frequency Noise and Thermal-Electric characteristics of the samples. We observe interesting relations between sample preparation procedures and electrical properties.

Composite zeolite catalytic tubular membranes containing rhodium(0) and ruthenium(0) in and on alumina tubes were prepared using the hydrothermal synthesis method termed “multi in situ crystallization” (MISC). The membranes were tested in the partial oxidation of methane to investigate membrane activities. Transition metal-dispersed zeolitic catalytic tubular membranes exhibit a high catalytic surface area, large membrane surface area and high chemical and thermal stabilities. The applicability of these membranes to the partial oxidation reaction is demonstrated.

An LTA membrane has been crystallized inside a porous ceramic tube and applied to synthesis of methanol from carbon dioxide and hydrogen in a zeolite membrane reactor (ZMR). The results obtained with the ZMR were compared with those gained from one traditional reactor (TR) used under the same operating conditions. CO 2 conversion obtained with the ZMR at 210 °C reached 17% under conditions where the equilibrium value without zeolite membrane (TR) is equal to about 6%.

Doxorubicin hydrochloride (DOX), is a class I anthracycline antibiotic (FDA approved in the 1970s) widely used as an effective chemotherapeutic drug for the treatment of many human neoplasms. Like most anticancer drugs, DOX can provoke severe toxicity to the body when it is administered at high doses systemically. Here we report the results of an investigation of drug adsorption on graphene oxide (GO) materials prepared by the Improved Hummer's method. High-purity GO has been prepared, characterized by XPS, UV-vis, FTIR-ATR, FESEM, UV- vis analyses, Zero Point Charge determinations and applied in the immobilization of doxorubicin, via simple noncovalent method. The adsorption percentage of the drug at pH 7 on GO was observed to be higher (equal to 90 %) than that obtained at acidic pH 3 (equal to 85%). Experimental result of adsorption of DOX on GO, obtained by FTIR-ATR spectroscopy analysis indicate that the inorganic material and the drug form and adduct by π-π stacking interactions.

In this work we use graphene oxide (GO) produced by improved Hummer's method, for adsorption of acridine orange dye (AO) in water. GO is a material containing functional groups such as carboxyl, epoxy, ketone, and hydroxyl, that can adsorb cationic dyes. Factors such as initial concentration of dye, the amount of GO, temperature and contact time were evaluated. Results show that the adsorption equilibrium, with the removal of 40% of the dye, is reached in approximately 1 hour, and that the adsorption capacity increases at higher initial concentrations. The highest value of AO adsorbed was 229.8 mg/g equivalent to 92% removal percentage by using AO initial concentration 0.10 mg/mL. FT-IR analysis of GO with adsorbed AO shows changes in the stretching vibrational bands, which corroborate the AO/GO interaction due to the functional groups present in GO. Furthermore, AO adsorbed on GO does not desorb back into water. Our results show that GO is an effective adsorbent and could be used to treat effluents contaminated with dyes.

Vanadium-silicalite-1 samples are readily prepared at 170 °C from fluoride-containing gels. The amounts of vanadium and fluoride salts were varied in gels of initial composition 10SiO 2 : x VO 2 :1.25TPABr: y MF:330H 2 O with the vanadium source=VOSO 4 , V 2 O 5 , VO(acac) 2 and 0.0 5 ⩽ x ⩾ 3.0 ; M=NH 4 , Na, K and y = 1 , 3, 5, 7, 10 and TPABr=tetrapropylammonium bromide. The influence of synthesis parameters (Na/Si, MF/Si, Si/V, the vanadium source) on the preparation of well-formed crystals was systematically investigated. Sodium and potassium cations show different behaviours with respect to ammonium ions on the crystallization rates and crystal aspect ratios. Crystal morphologies are strongly influenced by the nature of the fluoride salt added to the reaction mixture. The vanadium incorporation in zeolite crystals increases regularly with the initial transition metal and fluoride content in the reaction batch. Moreover, the vanadium incorporation is similar for the various salts used. The kinetic data show that the vanadium fluoride amount not only influences the reaction rates, but also the induction periods.

The Zero Valent Iron (ZVI) is the material most commonly used for permeable reactive barriers (PRB). For technical and economic reasons, hoter reactive substances usable in alternative to ZVI are investigated. The present study takes into account a vegetable fibers, the cabuya, investigating its capacity to retain heavy metals. The capacity of the cabuya fibers to adsorb heavy metals was verified in laboratory, by batch and column tests. The batch tests were carried out with cabuya and ZVI, using copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb). The results obtained by the cabuya fibers showed a very high adsorption capacity of heavy metals and resulted very similar to those obtained for the broom fibers in a previous study. The high value of the absorption capacity of the cabuya fibers was also confirmed by the analogous comparison made with the results of the batch tests carried out with ZVI. Column tests, using copper, zinc and cadmium, allowed to determine for the cabuya fibers the maximum removal percentage of the heavy metals considered, the corresponding times and the time ranges of the release phase. For each metal considered, for a given length and three different times, the constant of degradation of cabuya fibers was determined, obtaining values very close to those reported for broom fibers. The scalar behavior of heavy metal removal percentage was verified. An electron microscope analysis allowed to compare, by SEM images, the characteristics of the cabuya and broom fibers. Finally, to investigate the chemical structure of cabuya and broom fibers, the FTIR technique was used, obtaining their respective infrared spectra.

We synthesized various zeolite nanocrystals and composite membranes with mordenite (MOR), ZSM-5, and B-silicalite (MFI) structures under hydrothermal conditions and we demonstrated their ability to immobilize famotidine. Ion-exchange experiments using metal salt solutions were carried out to obtain Cu(II)- and Zn(II)-containing nanosized crystals. All zeolite particles were synthesized obtaining high purity, as evidenced by powder X-ray diffraction (XRD) analysis performed on the zeolite crystals and scraped films. The crystal and membrane morphologies and sizes were determined by scanning electron microscopy (FESEM). The equilibrium and kinetic characteristics of the drug on these materials were studied by varying the incubation time, the famotidine concentration and the pH values. The adsorption percentage of the drug at pH 7.4 in both Cu-MOR and B-MFI crystals was observed to be higher than that obtained with Cu-ZSM-5, Zn-ZSM-5, and Zn-MOR. The desorption behavior of B-silicalite after 1 h is remarkable and has important implications for biomedical applications. © 2012 Elsevier Inc. All rights reserved.

Thermal analysis of crystalline Metallosilicalite-1 precursors with various heteroatoms was carried out in a nitrogen atmosphere. Different interactions between tetrapropylammonium species and the zeolitic environment were evidenced, depending on the type of metallic complexes in the reaction medium. The results support the mechanism of Metallosilicalite-1 formation through a condensation process from the liquid phase.

The adsorption of cytochrome c on to zeolite crystals and membranes with different chemical composition and structure was studied. The structure and texture of zeolite materials were identified by X-ray diffraction (XRD) and scanning electron microscopy (FESEM), while the variation of protein conformation was studied by Fourier transform infrared attenuated total reflectance (FTIR-ATR) analysis. In order to separate the influence of zeolite structures from the effect of composite membranes, a through analysis of the cytochrome c adsorption was performed on different crystals by varying several experimental parameters such as: pH value, protein amount, zeolite structures and chemical compositions. It is shown that the electrostatic type of interaction seems to be of the utmost importance to govern the immobilization, while the zeolite Bronsted acidity of the support is the subordinate parameter which differentiates the adsorption performances of different zeolite structures (that distinct for chemical composition of the framework).

Zeolites due to their low toxicity and high compatibility are considered new biomaterials for medical applications. The surface adsorption behaviour of zeolite crystals and composite membranes was discussed in this research. The zeolite materials were synthesized by hydrothermal syntheses using different reaction gels to modulate the Brönsted acidity of the microporous structures. Spectrophotometric analyses were used to evaluate protein adsorption on these surfaces. This study revealed that zeolite chemical composition and structure influenced the kinetics of protein adsorption. Zeolite Y surface adsorbed greater amount of BSA than the other structures. The percentage of adsorption increases with temperature and depends on the pH of the solution, being highest at the pI of the protein. The influence of the membrane configuration on the protein adsorption was studied using different zeolite structures and crystallization types. It seems that the observed differences could depend on the type of hydrothermal crystallization inside the inorganic support.

The present paper reports the in situ hydrothermal synthesis of a composite mordenite membrane. In this process, mordenite forms at the surface and within the pores of a porous ceramic alumina support by nucleation and crystallization from a mixture containing alumina and silica species. The structure and texture of the composite membrane were identified by XRD and SEM, as well as by single gas permeation at room temperature with H2, N2, O2, Ar, CO, He and CH4. The permeation resulting as a function of transmembrane pressure revealed a small viscous flow contribution for gas transport through the MOR composite membrane. Furthermore, these preliminary results (order of gas permeance and ideal selectivities) suggest that Knudsen diffusion is the dominant transport mechanism for the investigated series of gases, although an ideal selectivity slightly higher than the Knudsen selectivity was obtained, namely α = 1.6 at Δp = 0.6 bar for CH4/N2.

Ferrisilicate analogs of zeolite beta have been investigated as catalysts for benzene isopropylation. Activity, selectivity, reaction kinetics and catalyst deactivation have been examined. Results have been compared with those obtained over Al-beta catalysts. Mixed Fe-Al-beta catalysts showed remarkably high activity and selectivity to cumene and diisopropylbenzene.

This work has been performed to test pure membranes of two zeolites as effective adsorbents for the removal of the cationic dye acridine orange (AO) from aqueous solution. The membranes were made through fast and easy method without additional reagents. Membrane made by 5A and 13X zeolites were called m-5A and m-13X, respectively. Adsorption of AO was studied in a batch system in conjunction with UV-visible analyses to determine de efficiency of m-13X and m-5A. Both membranes exhibited good adsorption performance. The influence of contact time on the amount of dye adsorbed onto membranes was investigated, showing high reduction in the first hours of contact. The adsorption efficiency after 18h was 85 % for m-13X, and 55% for m-5A. The kinetics of adsorption showed good agreement with the pseudo-second order model, giving an adsorbed amount of 1,73 and 2,36 mg/g for m-5A and m-13X, respectively. This study shows that m13X is a more effective adsorbent than m-5A for removal of AO from aqueous solutions.