Fourier Transform Infrared Spectroscopy Data Research Articles

Enhancing surface characteristics of Ti-6Al-4V for bio-implants using integrated anodization and thermal oxidation.

Modifications of Ti-6Al-4V surface roughness, wettability and composition are increasingly studied to improve cellular viability on biomedical implants involving Ti-6Al-4V. In this study, it is shown that modification of Ti-6Al-4V samples using anodization (for the formation of titania nanotubes) combined with thermal oxidation (TO) results in superior surface characteristics to those of a smooth, rough, anodized-smooth or anodized-rough surface alone. Surface characterization is performed using water contact angle (WCA) measurements, white-light interferometry, Fourier transform infrared spectroscopy (FTIRS), field emission scanning electron microscopy and grazing incidence X-ray diffraction (GIXRD). WCA measurements before TO indicate that anodized-smooth and anodized-rough samples are super-hydrophilic (WCA less than 5°); WCA of non-anodized smooth and rough surfaces are 57 ± 6° and 86 ± 7°, respectively. After TO at 450 °C for 3 hours, all samples become super-hydrophilic; however, three weeks after TO, smooth and rough surfaces become hydrophobic, while anodized-smooth and anodized-rough surfaces remain hydrophilic. FTIRS and GIXRD data show that the TO of anodized and non-anodized smooth samples results in anatase and rutile TiO2, of which anatase is favorable for cellular attachment. Micro-/nano-scale roughness and TO are discussed in the context of enhanced Ti-6Al-4V surface characteristics for improved cellular response.

STUDIES ON NEPHRITE AND JADEITE JADES BY FOURIER TRANSFORM INFRARED (FTIR) AND RAMAN SPECTROSCOPIC TECHNIQUES

The mineralogical properties of black nephrite jade from Western Australia are studied by Fourier transform infrared (FTIR) spectroscopy using both transmission and specular reflectance techniques in the 4000–400 cm-1 wavenumber region. The infrared absorption peaks in the 3700–3600 cm-1 region which are due to the O – H stretching mode provides a quantitative analysis of the Fe /( Fe + Mg ) ratio in the mineral composition of jade samples. The Fe /( Fe + Mg ) percentage in black nephrite is found to be higher than that in green nephrite, but comparable to that of actinolite (iron-rich nephrite). This implies that the mineralogy of black nephrite is closer to actinolite than tremolite. The jade is also characterized using Raman spectroscopy in the 1200–200 cm-1 region. Results from FTIR and Raman spectroscopic data of black nephrite jade are compared with those of green nephrite jade from New Zealand and jadeite jade from Myanmar. Black nephrite appears to have a slightly different chemical composition from green nephrite. Spectra from FTIR and Raman spectroscopic techniques were found to be useful in differentiating black nephrite, green nephrite, and green jadeite jades. Furthermore, data on refractive index, specific gravity, and hardness of black nephrite jade are measured and compared with those of green nephrite and of jadeite jade.

Low-temperature solution combustion synthesis of high performance LiNi0.5Mn1.5O4

High-voltage LiNi0.5Mn1.5O4 spinels were synthesized by a low temperature solution combustion method at 400°C, 600°C and 800°C for 3h. The phase composition, structural disordering, micro-morphologies and electrochemical properties of the products were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and constant current charge–discharge test. XRD analysis indicated that single phase LiNi0.5Mn1.5O4 powders with disordered Fd-3m structures were obtained by the method at 400°C, 600°C and 800°C. The crystallinity increased with increasing preparation temperatures. XRD and FTIR data indicated that the degree of structural disordering in the product prepared at 800°C was the largest and in the product prepared at 600°C was the least. SEM investigation demonstrated that the particle size and the crystal perfection of the products were increased with increasing temperatures. The particles of the product prepared at 600°C with ~200nm in size are well developed and homogeneously distributed. Charge/discharge curves and cycling performance tests at different current density indicated that the product prepared at 600°C had the largest specific capacity and the best cycling performance, due to its high purity, high crystallinity, small particle size as well as moderate amount of Mn3+ ions.

Tailoring odorant-binding protein coatings characteristics for surface acoustic wave biosensor development

In this study, wild type bovine odorant-binding proteins (wtbOBPs) were deposited by matrix-assisted pulsed laser evaporation (MAPLE) and utilized as active material on surface acoustic wave (SAW) biosensors. Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) were used to determine the chemical, morphological characteristics of the protein thin films. The FTIR data demonstrates that the functional groups of wtbOBPs do not suffer significant changes in the MAPLE-deposited films when compared to the reference one. The topographical studies show that the homogeneity, density and the roughness of the coatings are related mainly to the laser parameters (fluence and number of pulses). SAW biosensor responses to different concentrations of R-(–)-1-octen-3-ol (octenol) and R-(–)-carvone (carvone) were evaluated. The obtained sensitivities, achieved through the optimization of deposition parameters, demonstrated that MAPLE is a promising deposition technique for SAW biosensor implementation.

New investigation of distribution imaging and content uniformity of very low dose drugs using hot-melt extrusion method

The content uniformity of low dose drugs in dosage forms is very important for quality assurance. The aim of this study was to prepare uniformly and homogeneously distributed dosage forms of very low-dose drugs using twin screw hot-melt extrusion (HME) and to investigate the distribution of drugs using instrumental analyses. For the feasibility of HME method, a very low amount of coumarin-6, a fluorescent dye, was used to visualize distribution images using confocal laser scanning microscope (CLSM). Limaprost, tamsulosin and glimepiride were then used as low-dose model drugs to study the applicability of HME for content uniformity and distribution behaviors. Hydrophilic thermosensitive polymers with low melting point, such as Poloxamer188 and polyethylene glycol (PEG) 6000, were chosen as carriers. The melt extrusion was carried out around 50°C, at which both carriers were easily dissolved but model drugs remained in solid form. The physicochemical properties of the hot-melt extrudates, including differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FT-IR), were measured. Content uniformity of the drugs was also checked by HPLC. CLSM imaging showed that model drugs were well distributed throughout the hot-melt extrudate, giving better content uniformity with low batch-to-batch variations compared with simple physical mixtures. DSC, PXRD and FT-IR data showed that there was no interaction or interference between model drugs and thermosensitive polymers. The current HME methods could be used to prepare uniformly distributed and reproducible solid dosage forms containing very low dose drugs for further pharmaceutical applications.

Preformulation studies of itraconazole associated with benznidazole and pharmaceutical excipients

Recent studies have shown that the antifungal itraconazole (ITZ), when in associations with benznidazole (BNZ), is a potential treatment for Chagas disease. Therefore, the objective of the present study was to evaluate the compatibility of ITZ with BNZ and with selected pharmaceutical excipients. Differential scanning calorimetry (DSC), derivative thermogravimetry (DTG), Fourier transform infrared spectroscopy (FTIR), optical microscopy and kinetic analyses under isothermal conditions were performed. The results showed thermal interactions between ITZ and the excipients hydroxypropyl methylcellulose and polyvinylpyrrolidone. The FTIR data together with complementary tests revealed signs of drug decomposition in the presence of these materials. Thus, these excipients were considered incompatible with ITZ and should be avoided in solid dosage forms containing this drug. Moreover, it was found that associations between ITZ and BNZ are potentially unstable. Therefore, it is necessary to develop a pharmaceutical dosage form that avoids the processing of these drugs together and allows a stable pharmaceutical formulation to be obtained.

Crystal structure transformation and dielectric properties of polymer composites incorporating zinc oxide nanorods

Zinc oxide (ZnO) nanorods were synthesized using a modified wet chemical method. Poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), nanocomposites with different ZnO nanorods loadings were prepared via a solution blend route. Field emission scanning electron microscopic (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) were used to investigate the structure and morphology of the nanocomposites. XRD and FTIR data indicate that the incorporation of ZnO nanorods promote the crystalline structure transformation of P(VDF-HFP). As the content of ZnO nanorods increases, the β phase structure increases while the α phase decreases. In addition, the dielectric properties of the P(VDF-HFP) and its composites were systematically studied.

Temperature responsive functional polymeric thin films obtained by matrix assisted pulsed laser evaporation for cells attachment–detachment study

Multifunctional thin films used as thermoresponsive substrate for engineering cell sheets represent an important area in tissue engineering. As the morphology and the chemical characteristics of the thin films directly control their interaction with cells, it is important to correlate these characteristics with the biological answer. In this study, thermally sensitive poly(N-isopropylacrylamide), (pNIPAAm) thin films were prepared by matrix assisted pulsed laser evaporation and utilized in L929 cell adhesion and detachment studies. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to determine the pNIPAAm thin films chemical and morphological characteristics. The FTIR data demonstrated that the functional groups in the MAPLE-deposited films remained intact for fluences in the range of 200–600mJcm−2. Within this fluence range, the AFM topographical studies showed that the roughness of the coatings was dependent on laser fluence and the obtained surfaces were characterized by a granular aspect. L929 cell viability studies onto the pNIPAAm coatings showed little or no toxic effect for fluences below 600mJcm−2, while for higher fluences, viability was decreased with more than 50%. The adhesion and detachment of the cell was found to be mainly dependent on the film surface morphology.

Analysis of the Self-Association of Aliphatic Alcohols Using Fourier Transform Infrared (FT-IR) Spectroscopy

A number of industrially important systems contain molecules, such as alcohols, that form hydrogen bonds. To correlate the thermodynamic properties of such systems, assumptions must be made in modeling the chemical equilibrium. It has been found that the data can be fit to a high degree of accuracy if it is assumed that the system contains monomers, dimers, and trimers or tetramers. Alcohols are often modeled by an infinite equilibrium model that takes into account associated species of all sizes. In this model and in others as well, an additional assumption must be made concerning the values of the various equilibrium constants; it usually is assumed that all of the equilibrium constants for a given species are equal. In this work, Fourier transform infrared (FT-IR) spectroscopy has been used to study the chemical association of aliphatic alcohols. Analysis of FT-IR spectroscopic data was used to determine the species present in a mixture and the corresponding equilibrium constants and also to evaluate t...

Characterisation of phosphate coacervates for potential biomedical applications

In this study, amorphous (Na2O)x(CaO)0.50−x(P2O5)0.50·yH2O (where x = ∼0.15 and y = ∼3) samples were prepared by a coacervate method. Thermal analysis showed that two types of water molecules were present in the coacervate structures: one type loosely bound and the other part of the phosphate structure. Structural studies using Fourier transform infrared spectroscopy (FTIR) and X-ray total diffraction revealed the samples to have very similar structures to melt-quenched glasses of comparable composition. Furthermore, no significant structural differences were observed between samples prepared using calcium nitrate as the calcium source or those prepared from calcium chloride. A sample containing ∼1 mol% Ag2O was prepared to test the hypothesis that calcium phosphate coacervate materials could be used as delivery agents for antibacterial ions. This sample exhibited significant antibacterial activity against the bacterium Psuedomonas aeruginosa. FTIR data revealed the silver-doped sample to be structurally akin to the analogous silver-free sample.

EFFECT OF TiO2 ON STRUCTURE AND DIELECTRIC PROPERTIES OF RO-Al2O3-B2O3-SiO2(R = Ca, Mg) GLASSES

RO - Al 2 O 3- B 2 O 3- SiO 2( R = Ca , Mg ) glasses containing different concentrations of TiO 2 (ranging from 0 to 9 mol.%) were prepared by conventional melting method. When TiO 2 was present in lower concentrations (≤ 6 mol.%), Fourier-transform infrared spectroscopy (FTIR) indicated that titanium ions took part in network forming positions. However, for further increase in the concentration of TiO 2 (> 6 mol.%), FTIR data indicated the formation of TiO 4 tetrahedrons and TiO 6 octahedrons. The glass transition temperatures (Tg) were determined using a differential scanning calorimetry (DSC). The Tg variation with the concentration of TiO 2 showed an increasing trend up to 6 mol.% of TiO 2 and beyond this concentration, Tg was found to decrease. The dielectric constant εr and loss tan δ continued to decrease with the concentration of TiO 2 up to 6 mol.% and beyond that εr and tan δ were found to increase. This behavior was mainly explained in terms of the rigidity of glass network.

Synthesis, Surface Modification and Characterisation of Biocompatible Magnetic Iron Oxide Nanoparticles for Biomedical Applications

Superparamagnetic iron oxide nanoparticles (MNPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. These applications required that the MNPs such as iron oxide Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) having high magnetization values and particle size smaller than 100 nm. This paper reports the experimental detail for preparation of monodisperse oleic acid (OA)-coated Fe3O4 MNPs by chemical co-precipitation method to determine the optimum pH, initial temperature and stirring speed in order to obtain the MNPs with small particle size and size distribution that is needed for biomedical applications. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe2+ and Fe3+ solutions and steering speed. The monodisperse Fe3O4 MNPs coated with oleic acid with size of 7.8 ± 1.9 nm were successfully prepared at optimum pH 11, initial temperature of 45 °C and at stirring rate of 800 rpm. FTIR and XRD data reveal that the oleic acid molecules were adsorbed on the magnetic nanoparticles by chemisorption. Analyses of TEM show the oleic acid provided the Fe3O4 particles with better dispersibility. The synthesized Fe3O4 nanoparticles exhibited superparamagnetic behavior and the saturation magnetization of the Fe3O4 nanoparticles increased with the particle size.

Attenuated Total Reflectance-FT-IR Spectroscopy for Gunshot Residue Analysis: Potential for Ammunition Determination

The ability to link a suspect to a particular shooting incident is a principal task for many forensic investigators. Here, we attempt to achieve this goal by analysis of gunshot residue (GSR) through the use of attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR) combined with statistical analysis. The firearm discharge process is analogous to a complex chemical process. Therefore, the products of this process (GSR) will vary based upon numerous factors, including the specific combination of the firearm and ammunition which was discharged. Differentiation of FT-IR data, collected from GSR particles originating from three different firearm-ammunition combinations (0.38 in., 0.40 in., and 9 mm calibers), was achieved using projection to latent structures discriminant analysis (PLS-DA). The technique was cross (leave-one-out), both internally and externally, validated. External validation was achieved via assignment (caliber identification) of unknown FT-IR spectra from unknown GSR particles. The results demonstrate great potential for ATR-FT-IR spectroscopic analysis of GSR for forensic purposes.

Surface modification of TiO2 nanoparticles with AHAPS aminosilane: distinction between physisorption and chemisorption

This paper addresses the surface modification of TiO2 nanoparticles with n-(6-aminohexyl)aminopropyltrimethoxysilane (AHAPS) using various initial aminosilane concentrations. The main objective of this article is to show experimentally the importance of the physisorption during the grafting process. The distinction between chemisorbed and physisorbed aminosilane molecules on TiO2 is thoroughly analyzed. The surface of bare and modified TiO2 particles has been characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to gain a better understanding of the adsorption mechanism of AHAPS on TiO2. Quantitative information on surface energy of TiO2, in terms of adsorption energy sites and heterogeneity, has been investigated by quasi-equilibrium low-pressure adsorption technique using nitrogen and argon as probe molecules. The FTIR and XPS data are combined to estimate and discuss the chemisorbed and physisorbed contribution. The results demonstrate that both physisorption and chemisorption occurs but they display a different behavior. The physisorbed amounts are much higher than the chemisorbed amounts. This shows that the main part of the adsorbed layer is composed of physisorbed molecules. The physisorbed uptake depends highly on the AHAPS concentration while the chemisorbed amount remains constant. Quasi-equilibrium Ar derivative adsorption isotherms reveal that the AHAPS molecules are mostly located on the {101} and {001} faces of titania and that the two faces display the same reactivity toward AHAPS sorption. Nitrogen adsorption experiments show that the sorption takes place on the three polar surface sites of high energy. The molecules are chemisorbed onto the site displaying the highest energy while they are physisorbed on the two lower energy sites.

Simple organocatalytic route for the synthesis of starch esters

Starch acetates and starch butyrates with degree of substitution (DS) in the range of 0.06–1.54 were prepared by a simple direct solvent-free organocatalytic methodology of starch acylation. The starch esters synthesized have important applications in the food and pharmaceutical industries, among others. The acylation methodology used involves a non-toxic biobased α-hydroxycarboxylic acid as catalyst, and proceeds with high efficiency in absence of solvents. The effect of reaction time on the advance of starch modification was studied as a simple way to control the level of substitution achieved, when all other reaction parameters were kept constant. Starch esters were characterized by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). FTIR spectroscopy qualitatively confirmed the esterification of starch by the appearance of bands which are associated with esters groups. Scanning electron microscopy showed that the granular structure of the polysaccharide was preserved upon acylation, although acylated granules had rougher surfaces; and wrinkles, grooves and deformed zones appeared in some granules at high DS. Thermogravimetric analysis showed a gradual reduction in the water content of acylated starches, as well as noticeable changes in their thermal properties at increasing DS. X-ray diffraction analysis showed that the acetylation treatment led to lower crystallinity at increasing DS, although characteristic corn starch A-type patterns could be identified even at the highest DS achieved (DS=1.23). Specific bands and weight losses derived from FTIR and TGA data could be very well correlated with the substitution degree achieved in acetylated starches at DS lower/equal than 0.6. The organocatalytic methodology described for the synthesis of starch acetates and butyrates has the potential to be easily extended to the synthesis of other starch esters using a variety of anhydrides or carboxylic acids as acylating agents

Rapid collection and identification of a novel component from Clausena lansium Skeels leaves by means of three-dimensional preparative gas chromatography and nuclear magnetic resonance/infrared/mass spectrometric analysis

The present research reports the use of a three-dimensional preparative gas chromatography (prep GC) system, equipped with three Deans-switch devices and 5%diphenyl/wax/mid-polarity ionic liquid stationary phases, for the isolation of volatile components from a complex natural source, namely wampee essential oil (derived from Clausena lansium Skeels leaves). Collection was performed by using a simple and effective lab-constructed trapping device.Initially, an unknown (and abundant) wampee oil constituent was erroneously identified as α-sinensal, through an MS database search (a low similarity match was attained), performed after a GC-quadMS experiment., The unknown compound was then the isolated by using the novel prep GC system, in a highly pure form (at the mg level), and was correctly identified by using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectrometry (MS). Both FTIR and MS data were used to confirm the NMR information. The name given to the molecule was (2E,6E)-2-methyl-6-(4-methylcyclohex-3-enylidene)hept-2-enal.The results herein described will demonstrate the need for a high-resolution GC step, prior to analyte collection, in the prep GC analysis of complex samples.

Synthesis and Characterization of Low-Generation Polyamidoamine (PAMAM) Dendrimer–Sodium Montmorillonite (Na-MMT) Clay Nanocomposites

Polymer-inorganic nanocomposites are a recently developed class of materials that have altered physical or chemical properties with respect to the pure polymer, inorganic host, or their micro- and macrocomposites. Lower generation (G0.0-2.0) polyamidoamine (PAMAM) dendrimer/sodium montmorillonite (Na-MMT) nanocomposites were synthesized in a solution-phase exfoliation adsorption reaction. These are the first reports of the G0.0/ and G1.0/Na-MMT nanocomposites and of a structurally-ordered G2.0/Na-MMT. The materials were characterized using powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). PAMAM characteristics at acidic and basic aqueous media were studied using capillary zone electrophoresis (CZE). Pseudospherical PAMAM dendrimers in aqueous medium attain a highly flattened conformation within the confined space between MMT sheets upon nanocomposite formation. The nanocomposite structure depends on the PAMAM generation and the starting dendrimer/organic composition. G0.0 always forms monolayer structures (d = 0.42 nm), while G2.0 forms monolayer structure, mixed phase, and bilayer structures (d = 0.84 nm) at lower, intermediate, and higher organic content, respectively, showing an interesting monolayer to bilayer transition. G1.0 showed an intermediate behavior, with monolayer to mixed-phase transition at the reactant ratios studied. This monolayer arrangement of PAMAM/clay nanocomposites is reported for the first time. Maximum organic contents of G0.0 monolayer and G2.0 bilayer nanocomposites were ∼7% and ∼14%, respectively. Gallery expansions were similar to those observed with linear polymer intercalates, but the packing fractions (0.31-0.32) were 2-3 times lower. At acidic pH, the nanocomposites forming only monolayer structures are obtained, indicating a stronger electrostatic attraction between MMT and protonated PAMAM, and these nanocomposites formed more slowly and were more ordered. Na(+) ions play a significant role in nanocomposite formation. At high pH, PAMAMs show high mobility, ζ potential, and surface charge densities due to Na(+) complexation in solution. FTIR data indicates that both Na-MMT and PAMAM structural units are preserved in the nanocomposites obtained.

Protein-resistant polymer coatings obtained by matrix assisted pulsed laser evaporation

Adsorption of proteins and polysaccharides is known to facilitate microbial attachment and subsequent formation of biofilm on surfaces that ultimately results in its biofouling. Therefore, protein repellent modified surfaces are necessary to block the irreversible attachment of microorganisms. Within this context, the feasibility of using the Poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether (PEG-block-PCL Me) copolymer as potential protein-resistant coating was explored in this work. The films were deposited using Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique that allows good control of composition, thickness and homogeneity. The chemical and morphological characteristics of the films were examined using Fourier Transform Infrared Spectroscopy (FTIR), contact angle measurements and Atomic Force Microscopy (AFM). The FTIR data demonstrates that the functional groups in the MAPLE-deposited films remain intact, especially for fluences below 0.5Jcm−2. Optical Microscopy and AFM images show that the homogeneity and the roughness of the coatings are related to both laser parameters (fluence, number of pulses) and target composition. Protein adsorption tests were performed on the PEG-block-PCL Me copolymer coated glass and on bare glass surface as a control. The results show that the presence of copolymer as coating significantly reduces the adsorption of proteins.

Mineral stress affects the cell wall composition of grapevine (Vitis vinifera L.) callus

Grapevine (Vitis vinifera L.) is one of the most economically important fruit crops in the world. Deficit in nitrogen, phosphorus and sulfur nutrition impairs essential metabolic pathways. The influence of mineral stress in the composition of the plant cell wall (CW) has received residual attention. Using grapevine callus as a model system, 6 weeks deficiency of those elements caused a significant decrease in growth. Callus CWs were analyzed by Fourier transform infrared spectroscopy (FT-IR), by quantification of CW components and by immunolocalization of CW epitopes with monoclonal antibodies. PCA analysis of FT-IR data suggested changes in the main components of the CW in response to individual mineral stress. Decreased cellulose, modifications in pectin methyl esterification and increase of structural proteins were among the events disclosed by FT-IR analysis. Chemical analyses supported some of the assumptions and further disclosed an increase in lignin content under nitrogen deficiency, suggesting a compensation of cellulose by lignin. Moreover, polysaccharides of callus under mineral deficiency showed to be more tightly bonded to the CW, probably due to a more extensive cross-linking of the cellulose–hemicellulose network. Our work showed that mineral stress impacts the CW at different extents according to the withdrawn mineral element, and that the modifications in a given CW component are compensated by the synthesis and/or alternative linking between polymers. The overall results here described for the first time pinpoint the CW of Vitis callus different strategies to overcome mineral stress, depending on how essential they are to cell growth and plant development.

Simplified Synthesis of Swelling Na-4-Mica from Diatomite

A swelling Na-4-mica (a highly charged fluorophlogopite) has recently attracted much attention because of its unique combination of high charge (four charges per unit cell) and swelling and cation exchange properties. Synthetic mica (ideal composition of Na4Mg6Al4O20F4.xH2O) was prepared by a simplified single-step synthetic process (NaCl-melt method) from diatomite at 900 0 C for 5 h. The obtained micas were characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and 29 Si and 27 Al magic-angle-spinning nuclear magnetic resonance (MAS-NMR) spectroscopy. Powder XRD and FT-IR data showed that the swelling Na-4-mica was obtained from diatomite (which serves as a cost-effective aluminosilicate source) with a small particle size (mean 2 µm) as revealed by SEM. The 29 Si and 27 Al MAS-NMR revealed the Si and Al nearest neighbor environment as well as the presence of impurities such as glassy phase.