Synthesis and characterization of mesoporous zinc layered hydroxide-isoprocarb nanocomposite

The ion exchange method was used to intercalate a poor water-soluble insecticide, isoprocarb into zinc layered hydroxide (ZLH). PXRD analysis indicated the successful intercalation with good crystallinity for the resulting nanocomposite, with a basal spacing of 33.1 Å. FTIR analyses showing the resemblance of an absorption peak of the nanocomposite with the host and the guest anion. The thermal analysis confirmed that the nanocomposite had better thermal stability compared to the pristine isoprocarb. The nanocomposite also characterized by elemental and surface morphology analysis. The surface analyses of the host and nanocomposite showed mesoporous-type material characteristics. On the whole, the intercalation process decreased the pore size of the nanocomposite compared to the pristine host, layered zinc layered hydroxide-sodium dodecyl sulphate (ZLH-SDS). The obtained material is believed has a great potential as an environmentally friendly insecticide.     

Synthesis and characterization of a novel layered zinc phosphate

The syntheses and crystal structures of a novel layered zinc phosphate and its high temperature variant are described. Both structures were solved from powder diffraction data using both synchrotron and conventional X-ray radiation. The as-synthesized material (UiO-27-as) with composition [C₆H₁₇N₃]²⁺[Zn₃(HPO₄)(PO₄)₂]²⁻·H₂O crystallizes in the space group P2₁/c with a=12.67072(15), b=8.24293(8), c=18.48425(19) Å, β=109.1346(7)° and V=1823.904(35) ų. The zinc phosphate layers are built from corner sharing hexameric secondary building units. In the interlamellar space there are organic cations and water molecules. A high temperature variant exists around 200°C (UiO-27-200). This compound [C₆H₁₇N₃]²⁺[HZn₃(PO₄)₃]²⁻ crystallizes in the monoclinic space group P2₁/c with a=12.29010(23), b=8.39995(13), c=18.49914(30) Å, β=114.2504(11)° and V=1741.261(51) ų. The transformation to UiO-27-200 involves removal of the interlamellar water molecules. The atomic arrangement within the zinc phosphate layers is maintained; however, the layers are brought closer which leads to inter-layer hydrogen bonding interactions.     

Synthesis and characterization of chromia-pillared layered tetratitanate

The first chromia-pillared layered tetratitanate was prepared by the reaction of layered tetramethy-lammonium tetratitanate with chromium(Ⅲ) acetate [Cr(OAc)3] aqueous solution and subsequent calcination of the resultant solid product in air at 400℃. The obtained chromia-pillared layered tetratitanate has an interlayer distance of 1.06 nm and a high thermal stabih'ty up to 600℃. It was also found that calcination in N2 led to the chromia-pillared layered tetratitanate with relatively higher Brunauer-Emmett-Teller (BET) specific surface area (93.9 m2·g-1) and smaller average pore diameter (4.44 nm) than that in air (82.0 m2·g-1, 7.61 nm) . Both Bronsted and Lewis acid sites (mainly Lewis type) are present on the chromia-pillared layered tetratitanate (500℃, N2, 8 h) and strong enough to still remain a small proportion of pyridine upon outgassing at 250℃. Moreover, ammonia temperature-programmmed desorption (NH3-TPD) result showed that there were three NH3 desorption peaks at 160, 200and315℃, resp     

Synthesis and characterization of zinc oxide nanoparticles

The research is aimed at synthesis and characterization of nanoscaled zinc oxide particles and their application on linen fibrous supports, for thermal properties. To impart thermal activity to the fibrous nanocomposites, nanoparticles as well as fibrous nanocomposites were produced in different hydrothermal conditions of temperature (90 °C). To characterize the nanoparticles composition, their shape, size, and crystallinity, investigations technique, such as Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray powder diffractometry were used. Differential scanning calorimetry analysis profiles were also revealed. The thermal treatment of linen fabrics with nanosized ZnO does not modify significantly their thermal stability.     

Synthesis and characterization of a new layered lead borate

A new lead borate, Pb[B₈O₁₁(OH)₄], has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, FTIR, powder X-ray diffraction and thermogravimetric analysis. The compound crystallizes in the monoclinic system, space group P2₁/n (No. 14), , , , β=90.327(2)°, , and Z=4. The structure consists of layers of 9-membered borate rings enclosing Pb²⁺ cations. Adjacent borate layers are interconnected via ionic Pb-O bonds and hydrogen bonding to form a 3D supramolecular network.     

Synthesis and characterization of N-doped zinc oxide nanotetrapods

Nitrogen-doped (N-doped) self-assembled nanotetrapods ZnO were synthesized via chemical vapor deposition process using N₂O as a dopant source via vapor-solid (VS) growth. The decomposition of N₂O gas giving NO and NO₂ during the synthesis provided successful N-doping of the sample. All samples (N-doped and undoped) were characterized by XRD, SEM, TEM, EDX, photoluminescence (PL), Fourier transform infrared (FT-IR), and diffuse reflection spectra. After nitrogen-doping process, N-doped ZnO samples show the change in structural and optical properties. The detailed structure and the growth mechanism of individual ZnO tetrapod is characterized by TEM and SEM investigations. The TEM study gives the direct assumption about the formation of zincblende (sphalerite) structure on the initial stage of growth of N-doped tetrapods. Besides, SEM observation indicated that tetrapods have perfect tetrahedral symmetry. N-Doped ZnO samples exhibit a broad orange-red PL emission band, peaking near 2.1 eV, in good agreement with the deep-acceptor model for the nitrogen impurity. An IR absorption peak at 3146 cm^–1 at room temperature was observed for N-doped sample. This peak has been unambiguously assigned to N–H complex.     

半导体硫化锌纳米微粒的合成与表征

采用液相均沉淀法,用不同原料(采用不同硫源或金属离子螯合剂)从3个途径合成了不同粒径的半导体ZnS纳米粒子,并用透射电子显微镜、X射线粉末衍射仪对粒子进行表征.     

Synthesis and performance evaluation of novel cobalt hydroxychlorides for electrochemical supercapacitors

Co₂(OH)₃Cl has been prepared by a facile one pot sol-gel process. Two different solvents, ethylene glycol and glycerol, are used for the synthesis. The resulting samples are studied for their morphology, structure, and electrochemical stability upon cycling. The sample with ethylene glycol as solvent exhibits three-dimensional porous interconnected xerogel morphology, whereas that with glycerol shows a crystalline and non-porous nanoparticulate structure. The specific capacitance of the Co₂(OH)₃Cl prepared with ethylene glycol is 434 F/g, when the electrodes are cycled in 3 M KOH at a specific current 2 A/g, and with that of glycerol, it is 252 F/g. Interestingly, at a high current density of 25 A/g, Co₂(OH)₃Cl with ethylene glycol and glycerol showed 143 and 72 F/g, respectively. Ethylene glycol significantly modified the structure and morphology so as to attain a mesoporous Co₂(OH)₃Cl with high surface area, which in turn influenced its remarkable electrochemical behavior. With a significant specific capacity and electrochemical stability, the synthesized material is a novel potential candidate for supercapacitors.     

Synthesis and characterization of layered tetravalent metal terphenyl mono- and bis-phosphonates

The syntheses of p-terphenylphosphonic acid and p,p″-terphenyl-bis-phosphonic acid have been developed, and the resulting products were used to prepare layered Th(IV) and Zr(IV) phosphonates. The monoacidic terphenyl species formed a bilayered structure while the diacid created a pillared geometry. Mixed component phases were also produced. Synthesis, characterization, X-ray and thermal properties of these materials are discussed.     

Synthesis and characterization of a UV absorbent-intercalated Zn-Al layered double hydroxide

Zn-Al-layered double hydroxides (LDHs) containing the organic anion of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (HMBA), a highly efficient UV absorber, have been synthesized by reaction in air of HMBA with an LDH-carbonate precursor obtained by a process involving separate nucleation and aging steps. The structural properties, photo- and thermal stability of the resulting Zn-Al-HMBA-LDHs were characterized by PXRD, FT-IR and UV-visible spectroscopy and laser particle-size analysis. The results obtained indicated that Zn-Al-HMBA-LDHs synthesized by this method were relatively highly crystalline and had a narrow distribution of particle size. Intercalation of HMBA in the LDH interlayer galleries resulted in an enhanced photo- and thermal stability without affecting its UV absorption capacity; this shows that the hybrid HMBA-LDH phase has potential applications as a UV absorber.     

Synthesis and characterization of 5-fluorocytosine intercalated Zn-Al layered double hydroxide

In this paper, the intercalation of 5-fluorocytosine (5-FC) into a layered inorganic host, Zn-Al layered double hydroxide (LDH), has been carried out using coprecipitation method to obtain 5-FC/LDH nanohybrids. The intercalated amount (A_In) of 5-FC into the LDH is remarkably dependent on the molar ratio (R_F/M) of 5-FC to metal ions and the pH of coprecipitation system. The morphology of 5-FC molecules in 5-FC/LDH nanohybrids is dependent on the A_In. It is interestingly found that the morphology of the nanohybrid particles may be changed with the increase of R_F/M from hexagonal plate particles to threadlike particles. The in vitro drug release from the nanohybrids is remarkably lower than that from the corresponding physical mixture and pristine 5-FC at either pH 4.8 or pH 7.5. In addition, the release rate of 5-FC from the nanohybrid at pH 7.5 is remarkably lower than that at pH 4.8, this is due to a possible difference in the release mechanism. The obtained results show these drug-inorganic nanohybrids can be used as a potential drug delivery system.     

Synthesis and characterization of zinc titanate fibers by sol-electrospinning method

A facile and economic electrospinning approach has been developed for the synthesis of zinc titanate-rutile composite fibers as a nanofibrous mat at the first time. The composite fibers with different morphologies were obtained by calcination of the PVP/Ti(OC₄H₉)₄–Zn(CH₃COO)₂ fibers. The reaction mechanism was characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infraction spectroscopy (FT-IR) spectra techniques. According to the thermal analysis, the phase of ZnTiO₃ occurred at 450 °C and it decomposed at 885 °C. FE-SEM micrographs indicated that the as-spun fibers were round and had a rather uniform and smooth surface with the diameters in the range of 300–800 nm over its length. Its morphology is greatly affected by the calcination temperatures.     

Synthesis pretreatment and characterization of a magnetic layered double hydroxides fluorescent probe

Using magnetic layered double hydroxide （MLDH） as carrier of fluorescein （FLU）, a fluorescent composite of MLDH-FLU was prepared via intercalation reaction of ion change. The crystal properties of MLDH-FLU were investigated through XRD, IR, TEM and TG-DSC characterization. It is shown that the crystal type of MLDH-FLU composite matched well with R-hexagonal crystal system of MLDH, with crystal cell parameters of a, c and channel height h equal to 0.3199, 2.411 and 0.3267 nm respectively. The superabundant pigment adsorbed outside the composite should be cleared before interference with cells, but excessive wash would decrease stability and cause crystal phase transformation of MLDH.     

Synthesis and characterization of layered double hydroxides with a high aspect ratio

A new route for synthesis of Mg/Al layered double hydroxide (Mg₆Al₂(OH)₁₆(CO₃)·4H₂O) has been introduced, which can be considered as a modified calcination-rehydration method. Under the hydrothermal conditions, LDHs with a high aspect ratio were synthesized and characterized by inductively coupled plasma-atom emission spectrometer (ICP-AES), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermal measurement (TG-DTG) and scanning electron microscopy (SEM). XRD patterns display the crystalline enhanced with the increase of hydrothermal temperature and aging time. TG-DTG curves show the more stable LDHs were synthesized at higher temperature. SEM images indicate the lateral size of the synthesized LDHs locates at ca. 1-6 μm and the thickness at ca. 35-60 nm. And the particle size depends strongly on the treatment temperature and aging time. A buffer solution consisted of HCO₃⁻ and CO₃²⁻ keeps the pH of reaction system in a certain range and offers a low supersaturated reaction circumstance. This is of high importance for the formation of LDHs with a high aspect ratio.     

Synthesis,characterization and fungicidal activity of zinc diethyldithiocarbamate and phosphate

Monolayers of amphiphilic di-block copolymer, PEO₄₀-b-PMA(Az)₁₉ on water surface and solid surfaces, such as silicon wafer and quartz glass, were analyzed by surface pressure — molecular area (π-A) isotherm, UV-Vis spectroscopy, atomic force microscopy (AFM) and total X-ray reflectivity (TXR). The monolayer prepared at 22 mN m-1 consisted of H aggregated azobezene (Az) moieties, which orientated perpendicular to the solid surface. The monolayer structure, including H aggregated Az and orientation of Az, was stable after annealing at 98°C, at which temperature the hydrophilic PEO domain was the liquid phase and the hydrophobic PMA(Az) was in the smectic A phase.     

Organically pillared layered zinc hydroxides

The two organically pillared layered zinc hydroxides [Zn₂(OH)₂(ndc)], CPO-6, and [Zn₃(OH)₄(bpdc)], CPO-7, were obtained in hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc) and zinc nitrate (CPO-6) and 4,4′biphenyldicarboxylate (bpdc) and zinc nitrate (CPO-7), respectively. In CPO-6, the tetrahedral zinc atoms are connected by two μ₂-OH groups and two carboxylate oxygen atoms, forming infinite layers extending parallel to the bc-plane. These layers are pillared by ndc to form a three-dimensional structure. In CPO-7, the zinc hydroxide layers are containing four-, five- and six coordinated zinc atoms, and the layers are built like stairways running along the [001] direction. Each step is composed of three infinite chains running in the [010] direction. Both crystal structures were solved from conventional single crystal data. Crystal data for CPO-6: Monoclinic space group P2₁/c (No. 14), a=11.9703(7), b=7.8154(5), c=6.2428(4) Å, β=90.816(2)°, V=583.97(6) Å³ and Z=4. Crystal data for CPO-7: Monoclinic space group C2/c (No. 15), a=35.220(4), b=6.2658(8), c=14.8888(17) Å, β=112.580(4)°, V=3033.8(6) Å³ and Z=8. The compounds were further characterized by thermogravimetric- and chemical analysis.     

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (^DippL)ZnEt (3, ^DippL = [(2,6-ⁱPrC₆H₃)NC(CH₃)]₂CH⁻), a product assigned as the zinc-phosphide (^DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (^TolL)ZnEt (2, ^TolL = [(p-CH₃C₆H₄)NC(CH₃)]₂CH⁻) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (^TolL)₂Zn (5), an apparent product of comproportionation. (^MesAI)ZnEt (1, ^MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.     

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (^DippL)ZnEt (3, ^DippL = [(2,6-ⁱPrC₆H₃)NC(CH₃)]₂CH^?), a product assigned as the zinc-phosphide (^DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (^TolL)ZnEt (2, ^TolL = [(p-CH₃C₆H₄)NC(CH₃)]₂CH^?) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (^TolL)₂Zn (5), an apparent product of comproportionation. (^MesAI)ZnEt (1, ^MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.