A mixed-ligand metal-organic complex [Cd(C7H3N3O2)(C12H8N2)] n was synthesized by cadmium(II) nitrate, 1,10-phenanthroline(phen) and benzotriazole-5-carboxylate acid(H2btca). Single crystal X-ray analysis indicates that complex 1 has a two-dimensional layer structure and crystallizes in an orthorhombic space group(Pbca), with cell parameters, a=1.7422(6) nm, b=0.9264(3) nm, c=2.0729(7) nm, α=90°, β=90°, γ=90°, V=3.346(2) nm3, Z=8. Each central Cd(II) is six-coordinated by four N atoms, two of which are from 1,10-phenanthroline, and the other two from two different triazole nitrogen atoms and two O atoms from benzotriazole-5-carboxylate, forming a distorted octahedral geometry. Adjacent Cd(II) centers are bridged by benzotriazole-5-carboxylate molecules to form a one-dimensional chain, which is further connected by the nitrogen atoms of btca2− to form an extended two-dimensional wave-like layer, with OFF(offset face-to-face) stacking interactions between phen ligands in adjacent layers, which are helpful to forming the three-dimensional supramolecular structure.
Ternary solid complex was synthesized via hybridization of curcumin(Cur), hydroxyapatite(HAP), lanthanum( La) and acetic acid(HAc). The nano-scale hybrid composite of La-Cur/HAP was directly prepared by the wet method. The morphologies and structures of the composite were characterized by scanning electron microscopy (SEM), infrared(IR) spectroscopy, X-ray diffraction(XRD), transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy. The antibacterial activities were tested by methods of minimum inhibitory concentration (MIC) and minimum bactericidal concentration(MBC). The results show that the size of the La-Cur/HAP composite is less than 100 nm, and the composite exhibits strong bacteriostatic activity against Escherichia coli(E. coli) and Staphylococcus aureus(S. aureus) at low concentrations(in the range of 26–92 μg/mL). The composite can exhibit both of the bacteria and shows higher antibacterial activity against S. aureus than against E. coli. At the same time, La-Cur/HAP shows stronger antibacterial efficiency than ampicillin/HAP.
We reported a dripping solvothermal method for synthesizing metal-organic framework-5(MOF-5). It started from separately dissolving Zn(NO3)2 and terephthalic acid(H2BDC) in dimethyl formamide(DMF), and then dripping one solution into the other. Results of SEM, XRD and laser particle size distribution show that regular cubic-shaped and micro-crystallite powder of MOF-5 can be obtained. The d 0.5(volume-median-diameter) values are 4.32 μm for particles prepared by dripping Zn(NO3)2 into H2BDC(ZH) and 9.32 μm for those prepared by dripping H2BDC into Zn(NO3)2(HZ), much smaller than 22.7 μm that of particles prepared by the traditional adding water solvothermal method(L). The standard deviations of the particle size distributions fitted by the GaussAmp model are 2.49, 4.38 and 15.4 respectively for ZH, HZ and L, further revealing narrower size distributions of particles prepared by the dripping method. In addition, the Langmuir specific surface areas are 923 m2/g for ZH and 868 m2/g for HZ. The TGA results present mass losses of 4.18% and 3.62% at 105 °C, 17.19% and 14.78% at 245 °C, 39.04% and 34.85% at 600 °C separately for ZH and HZ, which correspond to the removal of H2O, DMF and the decomposition of MOF-5. This indicates that MOF-5 has a strong adsorption ability for small molecules. Besides, the mass loss of 48.39%(ZH) and 41.02%(HZ) between 400 °C and 600 °C are less than the theoretical value of 57.81% for MOF-5 decomposition to ZnO, suggesting that an impure phase with an extra amount of ZnO may exist in the cavities of MOF-5.
A fluorescent probe with a coumarin moiety bound to rhodamine 6G hydrazide(1) was synthesized. Its sensing behavior toward various metal ions was investigated with fluorescence methods. Compound 1 displays different fluorescence emission responses to Al3+ and Ca2+ at the same excitation wavelength in the visible light region, while no changes occur after the addition of other metal ions. The binding ratios of the complexs of 1-Al3+ and 1-Ca2+ are both 2:1 according to the Job plot and high resolution mass spectrometer(HRMS) experiments. Moreover, emission spectrum of 1-Ca2+ complex and absorption spectrum of the rhodamine dyes overlap largely. When Al3+ was added to the 1-Ca2+ system, calcium in complex 1-Ca2+ can be displaced by Al3+, resulting in the output of another ratiometric sensing signal, which demonstrates that the 1-Ca2+ complex can be served as a new and effective fluorescence resonance energy transfer(FRET) donor for rhodamine derivatives.
A simple and rapid sample preparation method of dispersive liquid-liquid microextraction(DLLME) was applied in the simultaneous determination of six parabens in the aqueous cosmetics. The analysis was performed on gas chromatography coupled with a flame ionization detection(GC-FID). The mixed solution containing 30 μL of chloroform(extraction solvent) and 300 μL of tetrahydrofuran(dispersive solvent) was rapidly injected into the sample solution for the purpose of microextraction. After that, the solution mentioned above was centrifuged at 4000 r/min for 10 min, and then the organic sediment phase was detected by GC-FID. The effects of experimental parameters, such as the extraction solvent and the volume of it, and the dispersive solvent and the volume of it, on the yield of the extraction were studied in detail. Under the optimum conditions, the enrichment factors of the target analytes range from 87 to 214. Linearity ranges are 0.05–10.0 μg/mL for methylparaben and 0.025–5.0 μg/mL for the other five parabens. The relative standard deviations(RSDs) are lower than 8.2%(n=6). The proposed method was applied to the analysis of six parabens in eleven aqueous cosmetics. The recoveries of the target analytes in the spiked real samples are in the range of 81.0%–103%.
Organic-inorganic hybrid and carbaryl-imprinted capillary monolith was synthesized via methacrylic acid(MAA) as functional monomer, γ-methacryloxypropyltrimethoxysilane(γ-MAPS) as crosslinker and carbaryl as template molecule in an acetonitrile/dichloromethane mixture(1:4, volume ratio). With the capillary column obtained from this monolith, three carbamates(carbaryl, fenobucarb and metolcarb) were separated effectively by electrochromatography with the k MIP/k NIP values of 7.57, 1.27 and 1.64, respectively. In 20 mmol/L phosphate buffer solution (pH=3.5) with 30% (volume fraction) of acetonitrile, carbaryl was separated directly from the three-carbamate mixture (carbaryl, fenobucarb and metolcarb) with an effective 15 cm-length imprinted column.
A novel water-soluble porphyrin[5,10,15,20-tetra(3-ethoxy-4-hydroxy-5-sulfonate)phenyl porphyrin, H2TEHPPS]_was designed and synthesized, which could be used as a potential fluorescence sensor to detect temperature changes. The studies were performed in solution phase and the concentration of H2TEHPPS was 2.0×10−5 mol/L. The optical properties of H2TEHPPS were investigated based on the UV and fluorescence spectra. The results show that the fluorescence intensity of H2TEHPPS is directly proportional to temperature in the range of 293–353 K. So H2TEHPPS can be used as a molecular temperature sensor in biomedical and other fields.
Several novel Schiff base macrocyclic compounds containing thiophene were synthesized from diethyl 3,4-dialkoxythiophene-2,5-dicarboxylate, cyanuric chloride, diethylamine and p-nitrophenol by reduction, oxidation, substitution and cyclization, and their structures were characterized by IR, NMR and electrospray ionization-mass spectrometer(ESI-MS). The studies on their UV-Vis absorption spectra show that Schiff base macrocycles 6–10 have selective recognition for Fe3+.
Methyl propiolate, formaldehyde, and various acyclic amines were assembled in one-pot into a series of 1,5-diaza-2,6-cyclooctadiene-3,7-dicarboxylates in moderate to good yields. This multiple-component reaction benefits from operational simplicity as well as good material economy.
A series of novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole ring was designed and synthesized. Their structures were confirmed by IR, 1H NMR, high resolution mass spectrometer(HRMS) and electrospray ionization-mass spectrometer(ESI-MS) combined with melting points and elemental analysis. Preliminary bioassays indicate that these compounds exhibit good insecticidal activity against Aphis laburni at 100 μg/mL, especially compound 6b shows mortality of no less than 95%. Most of the compounds show good activities against tobacco mosaic virus(TMV) with different modes in vivo at 100 μg/mL. Compound 6d standed out, showing a good insecticidal activity and very high induction effects against TMV in vivo. Collectively, our data demonstrate a new strategy for insect and virus control.
“Amano” lipase AS(lipase from Aspergillus niger), which naturally hydrolyzes triglycerides, was found promiscuously to catalyze multi-component reactions of aromatic aldehydes with malononitrile and β-naphthol to prepare naphthopyran derivatives in anhydrous organic solvents in moderate to good yields.
In order to find novel protoporphyrinogen oxidase inhibitors with high efficacy, broad-spectrum activity, and safety to crops, nine title compounds(4a–4i) were designed and synthesized by introducing pyrimidine moiety into the uracil skeleton with commercially herbicide butafenacil as the lead compound. Their structures were confirmed by 1H NMR, IR, mass spectroscopy and elemental analysis. The bioassay results indicate that most of compounds 4 tested exhibit good to excellent herbicidal activities against B. campestris, A. retroflexus, E. crusgalli and D. sanguinalis in pre-emergence treatment at a dose of 1.5 kg/ha(1 ha=104 m2), for example, compound 4i showed 100% inhibition against the four plants tested in pre-emergence treatment at a dose of 1.5 kg/ha. So, this type of skeleton can be used as a valuable lead compound for the further development of a pre-emergent herbicide.
Some 1-(6-chloroquinoxalin-2-yl)-2-[4-(trifluoromethyl)-2,6-dinitrophenyl]_hydrazine derivatives have been synthesized via both conventional and microwave assisted organic synthesis(MAOS) methods. The MAOS method is more effective on synthesizing these compounds than the conventional method in regard to the higher chemical yields of products(76%–98%) and the shorter reaction time(1–15 min).
A series of novel 3-bromo-1-(3-chloropyridin-2-yl)-N-hydroxy-N-aryl-1H-pyrazole-5-carboxamides was synthesized by the reaction of pyrazole carbonyl chloride with each of substituted phenylhydroxyamines. The latter ones were prepared in good yields by reducing substituted nitrobenzene compounds with Zn/NH4Cl reductant system in alcohol. Structures of the title compounds were determined by IR, 1H NMR, and HRMS. Their insecticidal and fungicidal activities were evaluated by larvicidal test against oriental armyworm and the mycelium growth rate method, respectively.
A series of p-tert-butylcalix[4]arene 1,3-distal and monosubstituted semicarbazones and thiosemicarbazones was preparedd by acid catalyzed condensation reaction of active calixarene aldehydes with semicarbazide and thiocarbazide in methanol. One representative single crystal was determined by X-ray dirraction method, which shows that calixarene exists in cone configuration and intramolecular hydrogen-bands exist in the crystal.
We designed and synthesized a 7-azaindole derivative(TH1082), which was characterized by 1H NMR and 13C-NMR. We investigated its antitumor effects on human melanoma A375 cells, human liver cancer SMMC cells and human breast cancer MCF-7 cells in vitro via 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and also explored the mechanism of antiproliferation of them. The results show that TH1082 significantly inhibited the proliferation of these cells to different extent. The IC50 values for A375 cells, SMMC cells and MCF-7 cells were 25.38, 48.70 and 76.94 μg/mL at 24 h, respectively. To observe cell morphological changes, acridine orange/ethidium bromide(AO/EB) staining and Hoechest33342/PI staining were carried out. These results indicate that TH1082 could induced the apoptosis of A375 cells. The apoptotic rates were (9.5±2.09)%, (18.9±2.25)% and (39.5±2.02)%(5, 10 and 20 μg/mL) for A375, SMMC and MCF-7 cell lines, respectively. Further, we determined the activities of caspase-3 and caspase-9 in A375 cells treated with TH1082 at different concentrations(0, 5, 10 and 20 μg/mL) or Z-VAD-FMK(20 μmol/L), a pan-caspase inhibitor for 24 h. The results show that TH1082 activated caspase-3 and caspase-9, and the activation could be blocked by Z-VAD-FMK. Taken together, these findings indicate that TH1082 could inhibit the proliferation of A375 cells via activating caspase-3 and caspase-9.
Two new 1,3-dithiole derivatives, 4,4′-{9-[4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-9H-fluorene-2,7-diyl} dipyridine(2a) and 3,3′-{9-[4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-9H-fluorene-2,7-diyl} dipyridine(2b) were synthesized and characterized by Fourier transform infrared(FTIR), 1H NMR, 13C NMR and mass spectroscopies. The crystal structure of compound 2b was also studied. The optimized conformations and molecular orbital diagrams of compounds 2a and 2b were illustrated via density functional theory(DFT). By the time-dependent DFT(TD-DFT) method, electronic absorption spectra of compounds 2a and 2b were predicted and the results achieved were in good agreement with the experimental data. The formation of the cationic radical during the electrochemical oxidation process was also proposed.
A novel kind of time-temperature indicator, SiO2-coated 2,4-hexadiyn-1,6-bis(ethylurea) microcapsules, has been fabricated by coating SiO2 on 2,4-hexadiyn-1,6-bis(ethylurea). This kind of microcapsules is a model hydrophilic indicator, its stability is improved. And temperature-induced color change is irreversible even under varying irradiation. The influences of ammonia, tetraethyl orthosilicate(TEOS) and temperature on the product have been investigated. 2,4-Hexadiyn-1,6-bis(ethylurea) and the coated particles have been characterized by means of elemental analysis, mass spectrum, FTIR and Raman spectra and DSC, SEM, TEM and DLS analyses. The results indicate that 2,4-hexadiyn-1,6-bis(ethylurea)/SiO2 ratios, ammonia concentration and temperature could modulate the monodispersity and size of the microcapsules. The experiments indicate that when the molar ratio of 2,4-hexadiyn-1,6-bis(ethylurea)/SiO2/ammonia is 1:3:3.5 and temperature is 40 °C, the obtained microcapsules are well coated with the best monodispersity. Such sustained-release and hydrophilic microcapsules have very good prospects as a novel time-temperature chromatic indicator.
Multidrug resistance(MDR) is a main factor to make the failure of chemotherapy. It is closely related to the over-expression of P-glycoprotein(P-gp), multidrug resistance protein(MRP) and breast cancer resistance protein( BCRP). Herein we reported a novel method to characterize MDR, taking advantage of the electrochemical property of chemotherapeutic drugs. Meanwhile, the definition of accumulation phase and retention phase has been improved. Furthermore, with specific modulators introduced to inhibit the relevant efflux pumps, the exact protein that mainly works in the cells employed in this study can be identified.
The activated carbon fiber(ACF) was prepared from polyacrylonitrile-based pre-oxidized fiber(PANOF) by KOH direct activation. The influence of activation conditions including impregnation ratio(the mass ratio of PANOF to KOH), activation temperature and activation time on the pore structure and electrochemical properties of ACF was investigated, and the corresponding activation mechanism was proposed. The ACF prepared at an activation temperature of 800 °C and an impregnation ratio(the mass ratio of PANOF to KOH) of 1:2 for an activation time of 1 h in 6 mol/L KOH solution exhibits a specific surface area of 3029 m2/g, a mesoporosity of 84.2% and a specific capacitance of 288 F/g, and shows a good capacitive performance. The prepared ACF can be used as the electrode material for supercapacitors.
A model is proposed to rapidly evaluate the individual hydrogen bonding energies in linear water chains. We regarded the two O-H bonds of a water molecule as two dipoles. The magnitude of the O-H bond dipole moment can be varied due to the other water molecules’ presence. An analytic potential energy function, which explicitly contains the permanent dipole-dipole interactions, the polarization interactions, the van der Waals interactions and the covalent interactions, was therefore established. The individual hydrogen bonding energies in a series of linear water chains were evaluated via the analytic potential energy function and compared with those obtained from the CP-corrected MP2/aug-cc-pVTZ calculations. The results show that the analytic potential energy function not only can produce the individual hydrogen bonding energies as accurately as the CP-corrected MP2/aug-cc-pVTZ method, but is very efficient as well, demonstrating the model proposed is reasonable and useful. Based on the individual hydrogen bonding energies obtained, the hydrogen bonding cooperativity in the linear water chains was explored and the natures of the hydrogen bonding in these water chains were discussed.
Theoretical calculations were carried out to predict the aqueous-phase acidities of a series of drug 1-phenyl-4-propylpiperazine and its derivatives. The performances of the density functional theory(DFT) methods B3LYP and B3P86, solvation models[the polarized continuum model(PCM) and the conductor-like polarized continuum model(CPCM)], and the basis set effect were tested. A comparison between the theoretical and experimental pK a values for para-substituted 1-phenyl-4-propylpiperazines reveals that the accuracy of B3LYP is better than that of B3P86, and the basis set 6-31++G(d,p) and the CPCM model are suitable for calculating pK a values of the substituted 1-phenyl-4-propylpiperazine. For the investigated compounds, a reasonable agreement between the experimental and calculated pK a values was also observed.
The interactions between two trinuclear Ru(II) complexes and calf thymus DNA(CT DNA) were studied via absorption spectroscopy, reverse salt titrations, binding stoichiometry, DNA melting experiments, as well as viscosity measurement. The results indicate that complexes 1 and 2 bind to DNA via the interaction of the planar π-delocalized system of the complexes with intrinsic binding constants of 4.18×105 and 3.85×106 L/mol, respectively, and non-electrostatic binding free energy makes a predominant contribution to the binding free energy. The in vitro cytotoxic activity of complexes 1 and 2 was evaluated by the MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide]_method. Complex 1 shows higher anticancer potency than complex 2 against four tumor cell lines. Further mechanism study indicates that complexes 1 and 2 can cause cell cycle arrest in the G2/M phase.
A novel energetic combustion catalyst, 1,8-dihydroxy-4,5-dinitroanthraquinone manganese salt (DHDNEMn), was synthesized by virtue of the metathesis reaction in a yield of 91%, and its structure was characterized by IR, element analysis and differential scanning calorimetry(DSC). The thermal decomposition reaction kinetics was studied by means of different heating rate DSC. The results show that the apparent activation energy and pre-exponential factor of the exothermic decomposition reaction of DHDNEMn obtained by Kissinger’s method are 162.3 kJ/mol and 1011.8 s−1, respectively. The kinetic equation of major exothermic decomposition reaction of DHDNEMn is $\frac{{d\alpha }}{{dT}} = \frac{{10^{11.8} }}{\beta }\frac{2}{5}(1 - \alpha )[ - \ln (1 - \alpha )]^{3/5} \exp ( - 1.623 \times 10^5 /RT)$. The entropy of activation(ΔS ≠), enthalpy of activation(ΔH ≠) and free energy of activation(ΔG ≠) of the first thermal decomposition are −24.49 J·mol−1·K−1, 185.20 kJ/mol and 199.29 kJ/mol(T=575.5 K), respectively. The self-accelerating decomposition temperature(T SADT) and critical temperature of thermal explosion(T b) are 562.9 and 580.0 K, respectively. The above-mentioned information on the thermal behavior is quite useful for analyzing and evaluating the stability and thermal safety of DHDNEMn.
Wastewater discharged from chemical oxygen demand(COD) testing instrument was generally difficult to treat due to its high content of heavy metals and very low pH. In this study, a kind of cysteine-functionalized magnetic nanoparticles(MNPs-Cys) was synthesized and used to treat the wastewater. The synthesized MNPs-Cys as the adsorbent for heavy metal removal from aqueous solutions were systematically investigated. The adsorption dynamic process fit the Langmuir isotherms well with a maximum adsorption capacity of 76.92 mg/g for Cu(II). The adsorbent could be easily regenerated by 0.1 mol/L HNO3, which exhibited a high adsorption performance within 10 cycles. This adsorbent, combined with a developed pretreatment approach, could make Cr(III), Hg(II) and Ag(I) in the wastewater discharged from COD testing instrument effectively removed and the removal efficiency is more than 99%. This work gave a new insight into the design and synthesis of high-performance materials for treating wastewater with heavy metals.
A detailed mechanism covering 545 species and 3105 reactions for high-temperature combustion of n-propylcyclohexane(n-PCH), generated via a mechanism generation program(ReaxGen) developed by our research group, was validated in this study. A semi-detailed mechanism involved with 195 species and 573 reactions and a skeletal mechanism concerned with 108 species and 393 reactions were obtained by means of rate-of-production analysis and path flux analysis(PFA), respectively. In order to validate the reliability of these mechanisms, ignition delay time, laminar flame speed and concentration profiles of important species were simulated with the help of CHEMKIN software. Numerically predicted results of our mechanisms are in very good agreement with available experimental data. Finally, major reaction pathways of n-PCH combustion and important reactions during the combustion process were investigated by reaction pathway analysis and sensitivity analysis, respectively. The results indicate that these mechanisms are reliable for describing the auto-ignition characteristics of n-PCH. These mechanisms would also be helpful to computational fluid dynamics(CFD) for engine design. Moreover, this systematic approach used in our study, which combines mechanism construction, simplification, validation and analysis for n-PCH, may also be employed to construct mechanisms for the high-temperature combustion of other cycloalkanes with one ring.
The electrochemical properties of CeCl3, dissolved in LiCl-KCl eutectic melt, were investigated by electrochemical techniques, such as cyclic voltammetry and square wave voltammetry on Mo electrode. It was shown that Ce(III) is reduced to Ce(0) based on a three-step mechanism. In a temperature range of 833–923 K, the diffusion coefficient of Ce(III) is lgD Ce(III)= −2.49–1704/T determined by means of the Berzins-Delahay equation with two different expressions under reversible and irreversible conditions. The apparent standard potential of a Ce(III)/Ce(0) red-ox system is $E_{Ce^{3 + } /Ce^0 }^{0*} $=3.551+0.0006132T(K) vs. Cl2/Cl−. Some thermochemical properties of CeCl3 solutions were also derived from the electrochemical measurements, such as the enthalpy, entropy, Gibbs free energies and the activity coefficients of Ce(III). The Gibbs free energy of a dilute solution of CeCl3 in this system was determined to be $\Delta G_{CeCl_3 }^{0*} $/(kJ·mol−1)= −1027.9+0.178T(K) And the activity coefficients, $\gamma _{CeCl_3 } $, range between (7.78–9.14)×10−3. Furthermore, the standard rate constant of kinetic reaction was calculated to be (4.94–9.72)×10−3 cm2/s and the reaction was regarded as a quasi-reversible reaction under the present experimental conditions at 833 K.
The interactions of each of three phenanthroline derivatives 1, 2 and 3 with the human telomeric i-motif DNA were investigated. The results suggest these compounds are potent binders. The compounds could stabilize the structure of i-motif DNA by π-π stacking. Moreover, the binding constants of the compounds with i-motif DNA were (2.71–8.12)×104 L·mol−1, and the binding stoichiometry ratio was 1:1. CD studies reveal that the binding by phenanthroline compounds perturbs the conformation of i-motif DNA.
The influences of temperature and CO2 pressure on the corrosion of nickel-based alloy G30 in the stratum water containing H2S/CO2 were investigated with the aid of electrochemical impedance spectroscopy(EIS), Mott-Schottky analysis and scanning electron microscopy(SEM). The results indicate that alloy G30 is in the passive state in the stratum water, which is related to the formation of the passive film on its surface. This passive film can significantly protect the substrate from further corrosion. And the film protection is enhanced with decreasing temperature and CO2 pressure. Auger electron spectrometry(AES) and X-ray photoelectron spectrometry(XPS) results reveal that the passive film shows the double-layer structure, i.e. the inner chromium oxide and the outer iron/nickel spinel oxides or hydroxides with Mo oxides dispersing throughout the inner and outer scale.
Transparent conductive boron-doped ZnO thin films were prepared by sol-gel spin coating method. The effect of doped boron concentration on the properties of the films was systematically discussed. The films were characterized by X-ray diffraction, atomic force microscopy, spectrophotometry, and Hall effect measurement system. All the doped and undoped ZnO films were of a single hexagonal structure, and showed a preferred orientation of (002). The particle size and surface roughness of the films decreased with increased doped boron concentration. All the films exhibited an average transmittance of approximate 90% in visible-light region and an energy gap of about 3.3 eV. The maximum carrier concentration, the highest carrier mobility and the lowest resistivity were observed at a doped boron concentration of 0.5%(molar fraction). Based on these results, we suggested that the saturation concentration of doped boron in ZnO film is 0.5%(molar fraction).
The basic photophysical characteristics of low bandgap polymer poly{2,7′-9,9-dioctylfluorene-alt-5-diethylhexyl-3,6-bis(5-bromothiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione}(PDPP-F) have been systematically investigated by means of theoretical and experimental methods. The quantum chemical calculations clarify the molecular structure and electronic transition properties of PDPP-F. The transient absorption data were used to compare the relaxation dynamics of PDPP-F in chlorobenzene and solid film. It is observed that the dynamics process of simulated emission relaxes much faster in comparison with that of excited state absorption in both the solution and solid film. Moreover, the excitation intensity-dependent dynamics of PDPP-F confirms that the interaction among intrachain excitons may occur under photoexcitation in the solution and solid film.
When the superamphiphobic meshes are immersed in water, the rough structures on steel wires are filled with air. The nanostructured superamphiphobic surfaces were prepared on the stainless-steel mesh. By adjusting the mesh size of the surface, the continuity of trapped air layer on the superamphiphobic surface underwater could be controlled. Then the underwater oil-wetting behavior on the prepared superamphiphobic mesh was investigated. The oil droplet spread out on the superamphiphobic surface without mesh and exhibited an oil contact angle of about 0° under water. But the oil contact angle formed on the superamphiphobic mesh surfaces and extended with increasing mesh size. We thought the discontinuity of trapped air layer on the surface and the entry of water into interval between the steel wires should be responsible for these behaviors.
A facile method was successfully developed to prepare a “pine needle-like” nanocomposite of carbon nanotubes/polythiophene(CNTs/PTh) in ethanol with the assistance of supercritical CO2(SC CO2). The experiment conditions such as mass ratio of thiophene monomer to carbon nanotubes, reaction temperature, and reaction time were optimized, and the morphology and thickness of PTh layers on CNTs were hence effectively controlled. The results of Fourier transform infrared(FTIR) spectra, X-ray photoelectron spectra(XPS) and Raman spectra indicate the π-π interactions between PTh and CNT. A possible formation mechanism about the unique microstructure was suggested by virtue of the morphological evolution of the nanocomposite. As a facile, environment benign, and adjustable method, the proposed method holds great potential in the preparation of functional hybrid nanocomposites with the help of SC CO2, which will be promising in the fields of nanofabrication and electrochemical device preparation.
In order to improve the efficiency of new adsorbent, grafting-allylamine bacterial cellulose(al-BC), response surface methodology(RSM) was used for the optimization of preparation process. Three factors affecting the yield of grafting reaction are the amount of allylamine, the concentration of ceric ammonium nitrate(CAN) and the concentration of nitric acid. Based on the regression coefficient analysis in the Box-Behnken design, a relationship between the preparation variable and grafting yield was obtained. Square error analysis on main factors, and multi-variable interactions were employed for studying grafting yield. The results show that at the conditions of CAN of 23.00 mmol/L CAN, 0.17 mol/L nitric acid, adding an amount of grafting-allylamine bacterial cellulose of 26.49 mL/L made grafting rate reach maximum of 24.25% at 40 °C after the reaction for 4 h. The experimental results are in good agreement with the calculation values via proposed regression equation, indicating that the equation could be used to predict and optimizate the preparation of grafting al-BC.