Longer Synthesis Time Research Articles

Steering the reaction kinetics of the MgO-V2O5 system toward selective synthesis of magnesium vanadates

Magnesium vanadates (MgV2O6, Mg2V2O7 and Mg3V2O8) are common redox catalysts for organic reactions and excellent energy storage materials. However, due to the diversity of magnesium vanadates and their interconvertibility, it is difficult to accurately synthesize a species of magnesium vanadate or control its stability during functioning. Herein, the reaction kinetics of MgO-V2O5 system was studied for controllable synthesis of magnesium vanadates. The MgO-V2O5 diffusion couples were prepared to explore the interface reaction characteristics of the MgO-V2O5 system at different reaction time. During reaction, the thickness of the diffusion layer and diffusion coefficient gradually increased and reached a maximal value of 29.55 μm and 6.06×10-11 cm2·s−1 at 10 h, which diffusion is faster than that of CaO-V2O5 system. Additionally, the interconvertible mechanisms of different magnesium vanadates were investigated using XRD and SEM/EDS techniques. MgV2O6 was produced during the synthesis of Mg2V2O7 in the initial 4 h, which converted into Mg2V2O7 at a longer synthesis time. Mg2V2O7 was found during the generation process of Mg3V2O8; with abundant MgO, Mg2V2O7 converted into Mg3V2O8. These findings provide important insights into the accurate control of magnesium vanadate synthesis and even the vanadium extraction process.

LDH-Indomethacin Nanoparticles Antitumoral Action: A Possible Coadjuvant Drug for Cancer Therapy.

Indomethacin (INDO) has a mechanism of action based on inhibiting fatty acids cyclooxygenase activity within the inflammation process. The action mechanism could be correlated with possible anticancer activity, but its high toxicity in normal tissues has made therapy difficult. By the coprecipitation method, the drug carried in a layered double hydroxides (LDH) hybrid matrix would reduce its undesired effects by promoting chemotherapeutic redirection. Therefore, different samples containing INDO intercalated in LDH were synthesized at temperatures of 50, 70, and 90 °C and synthesis times of 8, 16, 24, and 48 h, seeking the best structural organization. X-ray diffraction (XRD), vibrational Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), spectrophotometric analysis in UV-VIS, and differential thermogravimetric analysis (TGA/DTA) were used for characterization. Our results indicate that higher temperatures and longer synthesis time through coprecipitation reduce the possibility of INDO intercalation. However, it was possible to establish a time of 16 h and a temperature of 50 °C as the best conditions for intercalation. In vitro results confirmed the cell viability potential and anticancer activity in the LDH-INDO sample (16 h and 50 °C) for gastric cancer (AGP01, ACP02, and ACP03), breast cancer (MDA-MB-231 and MCF-7), melanoma (SK-MEL-19), lung fibroblast (MRC-5), and non-neoplastic gastric tissue (MN01) by MTT assay. Cell proliferation was inhibited, demonstrating higher and lower toxicity against MDA-MB-231 and SK-MEL-19. Thus, a clinical redirection of INDO is suggested as an integral and adjunctive anticancer medication in chemotherapy treatment.

Fast and Facile Microwave Synthesis of Cubic CuFe2O4 Nanoparticles for Electrochemical CO2 Reduction

Nanoparticles of cubic CuFe2O4 are obtained in a fast microwave‐assisted hydrothermal synthesis. By adjusting the pH value and solvent ratio (ethylene glycol to water), phase purity and high crystallinity is achieved at very short reaction times of 1 min, or low temperatures of 120 °C, without the need for subsequent heat treatment steps. The influence of the synthesis time or temperature on material properties and performance in electrochemical CO2 reduction to CO are investigated. While particle size and crystallinity are not changed significantly with longer synthesis times at 175 °C, prolonged heating results in a decrease of the degree of inversion, which leads to a decrease in the CO2 reduction ability. The best performance is observed for CuFe2O4 with an intermediate degree of inversion of approx. 0.75, together with the largest crystallite size and micro‐strain, as revealed by Rietveld refinement. For CuFe2O4 synthesized under these conditions, a CO evolution rate of 0.2 μmol h−1 g−1 is obtained at a Faradaic efficiency of 20%. The CO to H2 ratio is 1:3, which makes it a promising candidate for a sustainable production of syngas.

Galvanic-Cell Deposition Enables the Exposure of Bismuth Grain Boundary for Efficient Electroreduction of Carbon Dioxide.

Metallic bismuth (Bi) holds great promise in efficient conversion of carbon dioxide (CO2 ) into formate, yet the complicated synthetic routes and unobtrusive performance hinder the practical application. Herein, a facile galvanic-cell deposition method is proposed for the rapid and one-step synthesis of Bi nanodendrites. Compared to the traditional deposition method, it is found that the special galvanic-cell configuration can promote the exposure of low-angle grain boundaries. X-ray absorption spectroscopy, in situ characterizations and theoretical calculations indicate the electronical structures can be greatly tailored by the grain boundaries, which can facilitate the CO2 adsorption and intermediate formation. Consequently, the grain boundary-enriched Bi nanodendrites exhibit a high selectivity toward formate with an impressively high production rate of 557.2 µmol h-1 cm-2 at -0.94V versus reversible hydrogen electrode, which outperforms most of the state-of-the-art Bi-based electrocatalysts with longer synthesis time. This work provides a straightforward method for rapidly fabricating active Bi electrocatalysts, and explicitly reveals the critical effect of grain boundary in Bi nanostructures on CO2 reduction.

Effect of synthesis time on plasmonic properties of Ag dendritic nanoforests.

The effects of synthesis time on the plasmonic properties of Ag dendritic nanoforests on Si substrate (Ag-DNF/Si) samples synthesized through the fluoride-assisted galvanic replacement reaction were investigated. The Ag-DNF/Si samples were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, reflection spectroscopy, X-ray diffraction and surface-enhanced Raman spectroscopy (SERS). The prolonged reaction time led to the growth of an Ag-DNF layer and etched Si hole array. SEM images and variations in the fractal dimension index indicated that complex-structure, feather-like leaves became coral-like branches between 30 and 60 min of synthesis. The morphological variation during the growth of the Ag DNFs resulted in different optical responses to light illumination, especially those of light harvest and energy transformation. The sample achieved the most desirable light-to-heat conversion efficiency and SERS response with a 30 min growth time. A longer synthesis time or thicker Ag-DNF layer on the Si substrate did not have superior plasmonic properties.

Anti-Cancer and Anti-Bacterial Effects of Terfezia boudieri-Derived Silver Nanoparticles.

The use of nanoparticles has markedly increased in biomedical sciences. The silver nanoparticles (AgNPs) have been investigated for their applicability to deliver chemotherapeutic/antibacterial agents to treat cancer or infections disease. However, the existing chemical and physical methods of synthesizing AgNPs are considered inefficient, expensive and toxic. Natural products have emerged as viable candidates for nanoparticle production, including the use of Terfezia boudieri (T. boudieri), a member of the edible truffle family. Accordingly, our goal was to synthesize AgNPs using an aqueous extract of T. boudieri (green synthesized AgNPs). Since certain infectious agents are linked to cancer, we investigated their potential as anti-cancer and antibacterial agents. The synthesis of AgNPs was confirmed by the presence of an absorption peak at 450nm by spectroscopy. The physico-chemical properties of green synthesized AgNPs were analyzed by UV-Vis, FT-IR, XRD, SEM, and TEM. In addition, their potential to inhibit cancer cell (proliferation and the growth of infectious bacteria were investigated. The size of nanoparticles ranged between 20-30nm. They exerted significant cytotoxicity and bactericidal effects in a concentration and time-dependent manner compared to T. boudieri extract alone. Interestingly, the synthesis of smaller AgNPs was correlated with longer synthesis time and enhanced cytotoxic and bactericidal properties.

Room-temperature prepared bimetallic nanocrystalline MOF-74 as catalysts in the aerobic oxidation of cyclohexene

MOF-74 is probably the MOF material that best combine three key features for catalytic applications: compositional versatility, the presence of open metal sites and the possibility of becoming nanocrystalline, thus avoiding or minimizing any reactants/products diffusion problems within their pores. This work describes, for the first time, the room-temperature preparation of bimetallic nanocrystalline MOF-74 materials and their catalytic performance in the solvent-free oxidation of cyclohexene using oxygen as oxidant. Although the preparation of oligo-metallic MOF-74 has been already published and even certain catalytic and adsorption metallic synergism has been made clear, this work shows that the room temperature synthesis approach provides some further possibilities for controlling the metal distribution by two different strategies: (i) changing the order of metal addition and/or (ii) by synthesis time. The nanocrystalline Me-MOF-74 catalysts based on metal with redox behavior (Mn, Co, Cu) are significantly active in the aerobic oxidation of cyclohexene, whereas Zn is rather an inhibitor. In spite of such inhibitor role of Zn-MOF-74, the bimetallic Zn-M2-MOF-74 samples (M2 = Mn, Co, Cu) show catalytic performance similar to that of the monometallic counterparts M2-MOF-74, and therefore their turnover is considerably increased. The system Cu-Mg-MOF-74 was selected to study effect of different metal distribution within the crystal on their catalytic activity: Longer synthesis time and consecutive addition of Cu and then Mg (the reverse order did not lead to pure MOF-74 phase) favors the catalytic activity of the resultant materials. Finally, the CoMn combination of two of the three most active metals (samples CuMn, CoMn and CuCo) lead to a bimetallic catalyst with higher catalytic performance than the corresponding monometallic samples.

Tracking the crystallization behavior of high-silica FAU during AEI-type zeolite synthesis using acid treated FAU-type zeolite.

During AEI zeolite synthesis using acid treated FAU (AcT-FAU), we found the recrystallization of high-silica FAU with high crystallinity and Si/Al ratio of 6.1 using N,N-dimethyl-3,5-dimethylpiperidinium hydroxide (DMDMPOH) after 2 h, followed by the crystallization of AEI via FAU-to-AEI interzeolite conversion at a longer synthesis time. In order to understand the formation mechanism of high-silica FAU and generalize its direct synthesis, we have investigated this synthesis process. An analysis of the short-range structure of AcT-FAU revealed that it has an ordered aluminosilicate structure having a large fraction of 4-rings despite its low crystallinity. The changes in the composition of the products obtained at different synthesis times suggested that DMDMP+ plays a certain role in the stabilization of the FAU zeolite framework. Moreover, the results of thermogravimetric analysis showed that the thermal stability of DMDMP+ changed with the zeolite conversion. To the best of our knowledge, this is the first study to clarify the structure-directing effect of DMDMP+ on FAU zeolite formation.

Pseudocapacitive behaviour of FeSx grown on stainless steel up to 1.8 V in aqueous electrolyte

Abstract Iron sulfide was synthesized for 4 h, 7 h and 12 h by a hydrothermal process directly on stainless steel current collectors. The synthesis time determined the material morphology and electrochemical response. The shortest synthesis time promoted the formation of randomly oriented nanowires that evolved to nanosheets decorated with nanoflakes, organized in a cuboidal-like morphology upon longer synthesis times. XRD, Raman, FTIR and XPS investigations confirmed the formation of FeSx. The electrochemical activity was studied in a potential window ranging from −0.95 to 0 V and the material obtained after 7 h of synthesis stored the maximum specific capacitance of 730 mF cm−2 at the current density of 1 mA cm−2. This material also retained approximately 34% of its initial capacitance at 10 mA cm−2 and showed very good cycling stability, keeping around 95% of the specific capacitance after 2000 galvanostatic charge-discharge (GCD) cycles. The kinetic analysis of the electrochemical results revealed the predominance of diffusional controlled processes. An asymmetric cell was assembled using FeSx as negative electrode and carbon nanofoam (CNF) as positive electrode. The FeSx||CNF cell showed enhanced capacitive response in a potential window of 1.8 V in 1 M Na2SO4 electrolyte and delivered specific capacitance of 236 mF cm−2 at 0.5 mA cm−2 with good rate capability. The FeSx||CNF cell stored maximum energy density of 0.11 mW h cm−2 at the power density of 0.45 mW cm−2. The cell showed very good stability by retaining 83% of the initial capacitance after 2000 cycles of consecutive charge discharge.

Mechanism of Zr Incorporation in the Course of Hydrothermal Synthesis of Zeolite BEA.

The mechanism of Zr-BEA hydrothermal synthesis in fluoride media has been investigated through the detailed characterization of samples obtained at different synthesis times by XRD, XRF, TGA, multinuclear solid-state NMR, FTIR, SEM, TEM with EDS, XAS, and nitrogen sorption. The synthetic procedure involved hydrothermal crystallization of the gel with the following composition: 1SiO2:0.54TEAOH:0.54HF:0.005ZrO2:5.6H2O. The formation of open and closed Lewis acid sites was monitored by FTIR spectroscopy of adsorbed CO, while coordination of Zr was studied by XAS. The results show that the formation of Zr-BEA proceeds by two steps. In the first step, pure silica BEA is crystallized via a solid-solid hydrogel rearrangement mechanism. Zirconium species are occluded in Si-BEA crystals in the form of Zr-rich silicate particles. These particles do not provide for any appreciable Lewis acidity. In the second step, Zr incorporation into T positions of the zeolite structure takes place, leading to the formation of closed Zr sites, which are partially converted into open sites at longer synthesis times. It is demonstrated that the content of open and closed sites can be tuned by variation of the synthesis time.

Time Dependent Structural Evolution of Porous Organic Cage CC3

Herein we followed the structural evolution of a prototypical type of porous organic cage, CC3, as a function of synthesis time. Three distinctive crystal formation stages were identified: at short synthesis times, a rapid crystal growth stage in which amorphous agglomerates transformed into larger irregular particles was observed. At intermediate synthesis times, a decrease in crystal size over time was observed presumably due to crystal fragmentation, redissolution, and/or homogeneous nucleation. Finally, at longer synthesis times, a regrowth process was observed in which particles coalesced through Ostwald ripening leading to a continuous increase in crystal size. Molecular simulation studies, based on the construction of in silico CC3 models and simulation of XRD patterns and nitrogen isotherms, confirm the samples at different synthesis times to be a mixture of CC3α and CC3-amorphous phases. The CC3α phase is found to contract at different synthesis times, and the amorphous phase is found to essentia...

Radiolabeling of DOTA-like conjugated peptides with generator-produced (68)Ga and using NaCl-based cationic elution method.

Gallium-68 (68Ga) is a generator-produced radionuclide with a short half-life (t½ = 68 min) that is particularly well suited for molecular imaging by positron emission tomography (PET). Methods have been developed to synthesize 68Ga-labeled imaging agents possessing certain drawbacks, such as longer synthesis time because of a required final purification step, the use of organic solvents or concentrated hydrochloric acid (HCl). In our manuscript, we provide a detailed protocol for the use of an advantageous sodium chloride (NaCl)-based method for radiolabeling of chelator-modified peptides for molecular imaging. By working in a lead-shielded hot-cell system, 68Ga3+ of the generator eluate is trapped on a cation exchanger cartridge (100 mg, ∼8 mm long and 5 mm diameter) and then eluted with acidified 5 M NaCl solution directly into a sodium acetate-buffered solution containing a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) or DOTA-like chelator-modified peptide. The main advantages of this procedure are the high efficiency and the absence of organic solvents. It can be applied to a variety of peptides, which are stable in 1 M NaCl solution at a pH value of 3–4 during reaction. After labeling, neutralization, sterile filtration and quality control (instant thin-layer chromatography (iTLC), HPLC and pH), the radiopharmaceutical can be directly administered to patients, without determination of organic solvents, which reduces the overall synthesis-to-release time. This procedure has been adapted easily to automated synthesis modules, which leads to a rapid preparation of 68Ga radiopharmaceuticals (12–16 min).

Synthesis of surface bound silver nanoparticles on cellulose fibers using lignin as multi-functional agent

Lignin has proven to be highly effective “green” multi-functional binding, complexing and reducing agents for silver cations as well as capping agents for the synthesis of silver nanoparticles on ultra-fine cellulose fibrous membranes. Silver nanoparticles could be synthesized in 10min to be densely distributed and stably bound on the cellulose fiber surfaces at up to 2.9% in mass. Silver nanoparticle increased in sizes from 5 to 100nm and became more polydispersed in size distribution on larger fibers and with longer synthesis time. These cellulose fiber bound silver nanoparticles did not agglomerate under elevated temperatures and showed improved thermal stability. The presence of alkali lignin conferred moderate UV absorbing ability in both UV-B and UV-C regions whereas the bound silver nanoparticles exhibited excellent antibacterial activities toward Escherichia coli.

Improvement of SiC nanopowder synthesis by sol–gel method via TEOS/resin phenolic precursors

In the present study, silicon carbide powder with the particle size lower than 50 nm has been synthesized by sol–gel method using the four-component system of alcohol–alkoxide–dispersant–resin in acidic conditions. The most significant parameters investigated in the current research include: pH, APC (ammonium polycarboxylate) dispersants, process temperature and soaking time. Sol–gel processing was performed in an alcoholic system as the averaged particle size in acidic pH ranges was found to be lower than 10 nm. Adding ammonium polycarboxylate resulted in stability of precursors within the sol via rendering electrosteric mechanisms. Powder properties were characterized using various analyses as: nuclear magnetic resonance, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). XRD analysis revealed the presence of cubic β-SiC phase, while the FE-SEM images confirmed that a longer synthesis time could lead to a morphological variation from spherical shapes to whisker. TEM/HRTEM images as well as their diffraction pattern verified the synthesis of carbide crystalline particles with size of less than 50 nm. HRTEM images of synthesized particles demonstrated ABCABC atomic arrangement, verifying their cubic structure in the form of β-SiC.

탄화규소 결정상의 종류가 탄화규소 표면에 ZSM-5가 형성되는데 미치는 영향

<TEX>${\alpha}$</TEX>-상 과 <TEX>${\beta}$</TEX>-상 두 가지 종류의 탄화규소(SiC) 입자 표면에 수열 합성 방법으로 ZSM-5 결정을 형성하였다. SiC는 <TEX>$50{\mu}m$</TEX> 이상이 되는 크기의 입자를 사용하였으며, ZSM-5 결정이 SiC 표면에서부터 성장하도록 유도하기 위하여 합성 단계에 앞서 SiC 표면에 산화층을 형성하였으며, 수열합성 온도와 시간을 변화시켜 보았다. 그 결과 <TEX>${\beta}$</TEX>-SiC는 <TEX>$900^{\circ}C$</TEX> 조건에서도 산화막이 형성되었으며, 특히 <TEX>$150^{\circ}C$</TEX> 합성 조건에서 ZSM-5가 <TEX>${\beta}$</TEX>-SiC 표면에서부터 성장하였음이 뚜렷이 관찰되었다. <TEX>$200^{\circ}C$</TEX> 조건에서는 ZSM-5의 결정의 크기가 성장할 뿐 아니라, 시간의 증가에 따라 결정의 형태가 뚜렷해지고 SiC 표면에 도포되는 양이 증가하는 것을 확인할 수 있었다. ZSM-5 crystals grew on the surface of <TEX>${\alpha}$</TEX>-SiC and <TEX>${\beta}$</TEX>-SiC particles by hydrothermal synthesis method. SiC particles which were > <TEX>$50{\mu}m$</TEX> of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on <TEX>${\beta}$</TEX>-SiC at <TEX>$900^{\circ}C$</TEX> in air, and it was controlled to grow ZSM-5 grew from the <TEX>${\beta}$</TEX>-SiC surface with <TEX>$150^{\circ}C$</TEX> synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of <TEX>${\beta}$</TEX>-SiC. When the synthesis temperature was <TEX>$200^{\circ}C$</TEX>, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.

Microwave-assisted modulated synthesis of zirconium-based metal–organic framework (Zr-MOF) for hydrogen storage applications

Abstract Zirconium-based metal–organic framework (Zr-MOF) was synthesized using a microwave-assisted modulated method in a short reaction time of 5 min. The Zr-MOF material was highly crystalline with well-defined octahedral shaped crystals, and it exhibited comparable hydrogen storage capacity to Zr-MOF of similar specific surface area synthesized using conventional methods with much longer synthesis time.

Synthesis and nucleation-growth mechanism of almost catalyst-free carbon nanotubes grown from Fe-filled sphere-like graphene-shell surface

This finding focuses on the optimization of synthesis time for the transformation of Fe-filled spherical-like graphene shell (GS) to almost catalyst-free carbon nanotube (CNT) structure using two-stage catalytic chemical vapor deposition apparatus. The camphor oil and ferrocene were used as carbon precursor and catalyst respectively, following the variety growth of graphene-family nanomaterials for 2, 4, 6, 8, 10, 30, and 60 min at 800°C synthesis temperature. The graphene-family nanomaterial properties were characterized using field emission scanning electron microscope, high resolution transmission electron microscope, micro-Raman spectrometer, thermogravimetric, and carbon-hydrogen-nitrogen-sulfur/oxygen (CHNS/O) analyzer. The result of field emission scanning electron microscopy analysis reveals that the CNTs were observed with high aspect ratio at 60-min synthesis time. The dependence of integrated intensity ratio of D-band and G-band (ID/IG) presented that ID/IG ratio sharply decreases with longer synthesis time. At higher synthesis time, thermogravimetric and CHNS/O analysis of CNT can obviously improve with decreases of non-carbonaceous material and transition metal catalyst. The nucleation-growth model of Fe-filled spherical-like GS to almost catalyst-free CNT has been highlighted to explain the change in growth mode.

Synthesis and Characterization of Ceramic Membranes (W‐Type Zeolite Membranes)

In this article, effects of synthesis parameters (synthesis temperature, synthesis time, and number of layers) on W‐type zeolite membranes synthesized over flat SUS supports for O2/SF6 gas separation were experimentally investigated. Experiments were carried out at these levels of synthesis temperature: 165°C, 185°C, and 200°C; synthesis time: 6, 12, and 18 h and number of layers: 1 and 2. Permeation measurements, XRD and SEM analysis were used for characterization of the synthesized membranes. The results showed that increasing synthesis temperature from 165°C up to 185°C increases separation factor of O2/SF6, however, further increasing decreases the separation performance. The same trend was observed for synthesis time for the single layer synthesized zeolite W membrane, although for the double layer synthesized zeolite W membrane, separation factor increased with increasing synthesis time. Repetition of layering has a net positive effect on separation factor of O2/SF6, and negative effect on permeation flux through the membranes. This behavior was attributed to the dual effect of synthesis temperature and synthesis time on selectivity. More zeolite crystals are deposited and larger crystals are formed at higher synthesis temperatures and longer synthesis times. Well W‐type zeolite membrane was synthesized at 185°C for 18 h with two repeating layers with a high separation factor of 20.1.

Microfluidic labeling of biomolecules with radiometals for use in nuclear medicine

Radiometal-based radiopharmaceuticals, used as imaging and therapeutic agents in nuclear medicine, consist of a radiometal that is bound to a targeting biomolecule (BM) using a bifunctional chelator (BFC). Conventional, macroscale radiolabeling methods use an excess of the BFC-BM conjugate (ligand) to achieve high radiolabeling yields. Subsequently, to achieve maximal specific activity (minimal amount of unlabeled ligand), extensive chromatographic purification is required to remove unlabeled ligand, often resulting in longer synthesis times and loss of imaging sensitivity due to radioactive decay. Here we describe a microreactor that overcomes the above issues through integration of efficient mixing and heating strategies while working with small volumes of concentrated reagents. As a model reaction, we radiolabel 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated to the peptide cyclo(Arg-Gly-Asp-DPhe-Lys) with (64)Cu(2+). We show that the microreactor (made from polydimethylsiloxane and glass) can withstand 260 mCi of activity over 720 hours and retains only minimal amounts of (64)Cu(2+) (<5%) upon repeated use. A direct comparison between the radiolabeling yields obtained using the microreactor and conventional radiolabeling methods shows that improved mixing and heat transfer in the microreactor leads to higher yields for identical reaction conditions. Most importantly, by using small volumes (~10 µL) of concentrated solutions of reagents (>50 µM), yields of over 90% can be achieved in the microreactor when using a 1:1 stoichiometry of radiometal to BFC-BM. These high yields eliminate the need for use of excess amounts of often precious BM and obviate the need for a chromatographic purification process to remove unlabeled ligand. The results reported here demonstrate the potential of microreactor technology to improve the production of patient-tailored doses of radiometal-based radiopharmaceuticals in the clinic.

Synthesis of mordenite using kaolin as Si and Al source

The main purpose of this work was to study mordenite synthesis using kaolin as a Si and Al source. The influence of crystallization time and seed addition were studied. The obtained zeolites were characterized by: XRD, SEM, nitrogen adsorption and chemical analysis. Kaolin showed to be a promising source of Si and Al for mordenite synthesis. Seed addition led to more highly crystalline phases. Kaolin yielded mordenite whereas ZSM-5 was obtained from calcined kaolin. Longer synthesis times and seed addition favored mordenite formation.