Based on surface molecule self-assembly and photocatalytic lithography techniques, superhydrophilic/superhydrophobic micropatterns were fabricated on TiO₂ films. Micropatterned calcium phosphate (CaP) films were successfully fabricated by the as-prepared superhydrophilic/superhydrophobic template combined with the electrochemical deposition method. Scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) indicated that micropatterned CaP films with a high spatial resolution could be constructed using the superhydrophilic/superhydrophobic micropatterns as templates. In vitro MG-63 cell tests of the micropatterned CaP films showed that the cells selectively adhered to the tiny CaP film units, which is promising for the control of the adherent growth of the cells on the tiny units and to achieve a high throughput evaluation of the cell behavior.

Intrinsically disordered proteins (IDPs) are a new class of proteins which lack a unique tertiary structure under native conditions while possessing essential biological functions. They take part in various physiological processes such as signal transduction, transcription and translation regulation, and protein modification. The discovery of IDPs challenges the conventional protein “sequence-structure-function” paradigm. In this review, we first overview the history of the conventional protein paradigm and the discovery of IDPs. Then we discuss the characteristics of IDPs in terms of sequence, structure, and biological function. Taking molecular recognition processes as an example, we further introduce current opinions on the advantages of IDPs in binding. Finally, we analyze possible applications of the study of IDPs such as further understanding the protein folding mechanism, improving protein structure determination, providing new clues for protein design and new targets for drug design. The current status of IDPs study in China is also briefly presented.

Graphene, a recently discovered carbon nanomaterial with carbon atoms tightly packed into a two dimensional honeycomb lattice, possesses many novel and unique physical and chemical properties because of its unusual monolayer atomic structure. Graphene has received a great deal of attention in fundamental and applied research. This review presents the current status of graphene synthesis, functionalization, and applications in chemistry. Specifically, the use of graphene for the fabrication of chemically modified electrodes, the preparation of chemical power sources, catalyst and medicinal matrices, and in gas sensors are summarized. Finally, further applications based on graphene are briefly introduced.

The influence of water-soluble macromolecules on the crystallization of calcium carbonate is reviewed combining with our work. The mechanisms are interpreted based on the analysis of calcium carbonate crystallization in the presence of biomacromolecules, synthetic polymers, or mixtures of the polymer and surfactants. This paper provides not only the methods for the crystallization of calcium carbonate consisting of different resultant morphologies, polymorphs, and sizes, but also a theoretical guide for industrial production.

Caffeine, theophylline, and aminophylline are important methyl-substituted xanthines and are widely used in clinics. In this work, the thermodynamic characteristics of the three drugs were studied by adiabatic calorimetry, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The low temperature molar heat capacities of caffeine (in the β crystal form), theophylline and aminophylline were measured by heating the system from 80 to 370 K using an adiabatic calorimeter. The results indicate that the molar heat capacity of aminophylline is the largest while that of theophylline is the smallest. The experimental molar heat capacities of the three drugs were fitted to a polynomial of C_{p, m} vs the reduced temperature (t) by means of the least fitting square method from 80 to 370 K. Their molar heat capacities at 298.15 K were calculated to be 226.49 J·K^-1·mol^-1 (for caffeine), 218.13 J·K^-1·mol^-1 (for theophylline), and 554.78 J·K^-1·mol^-1 (for aminophylline) using the polynomial C_{p, m}-t. Thermodynamic parameters (such as enthalpies and entropies relative to 298.15 K) were calculated for these drugs based on the polynomial C_{p, m}-t. The results of thermal analysis show that the order of thermal stability for these drugs is aminophylline＜caffeine＜theophylline. The temperatures, enthalpies and entropies of the phase transitions for caffeine and theophylline were obtained by DSC. The stabilities of the molecular structures for caffeine and theophylline were calculated by a first-principles calculation based on density functional theory. The results imply that the stability of the caffeine molecule is lower than that of theophylline and this is in od agreement with the experimental results.

The enthalpies of mixing for model protein compounds (glycine, alanine, N,N-dimethyl formamide (DMF) and N,N-dimethyl acetamide (DMA)) with diols (1, 3-butanediol and 2, 3-butanediol) and their respective enthalpies of dilution in aqueous solutions at 310.15 K were determined by flow microcalorimetric measurements. Heterotactic enthalpic interaction coefficients (h_xy, h_xxy, h_xyy) were obtained by analyzing these experimental results according to McMillan-Mayer theory. The results indicated that the hxy values were all positive with a dominant endothermic effect and the coefficients decreased according to the order of h_xy(DMA)>h_xy(Ala)>h_xy(Gly)>h_xy(DMF) and h_xy(2,3-butanediol)>h_xy(1,3-butanediol). Based on these results, we discussed solute-solute and solute-solvent interactions with regards to the influence of the relative position of the diol functional groups on the value of hxy. We found that the hydrogen bonds between DMF or DMA and the diols were strong, and because of the od polarizability of DMF's resonance structure, hydrogen bonds between DMF and the diols were further strengthened.

We used the potentiometric titration technique to study the deprotonation reactions at aqueous mesoporous silica surfaces. The concentration of surface proton binding sites was obtained by the Gran plot method using the acid-base titration data. The relevant equilibrium constants of the surfaces in terms of the constant capacitance model (CCM) were determined based on the experimental results using the FITEQL 4.0 program. The results indicate that the surface deprotonation behavior of the mesoporous silica suspensions is significantly different from that of amorphous silica. This behavior can be described by two surface reactions with surface bidentate and monodentate deprotonation constants of pK_a1=6.78±0.15 and pK_a2=10.25±0.22, respectively. Using these deprotonation constants, we established a surface speciation diagram for mesoporous silica in aqueous suspensions as a function of pH and discussed the effect of surface capacitance on surface speciation.

We designed an oxidation reactor for abietic acid and rosin oxidation under ultraviolet light irradiation. The oxidation process of abietic acid and rosin were determined by UV spectrophotometry and the rate constants (k_b) and activation energy (E_a) of the oxidation process were calculated. The kinetic effect of the quantum efficiency (Φ) and the light intensity (I) on the photooxidation reaction were also investigated. The experimental results showed that the photooxidation kinetics of abietic acid and rosin were pseudo first order. The relationship between the natural logarithm of rate constant (lnk_b) and the natural logarithm of the light intensity (lnI) is linear. When the reaction temperatures were 20, 25, and 35 ℃, the apparent reaction rate constants of abietic acid were: lnk_b=0.9911lnI-8.860, lnk_b=0.8786lnI-8.069, and lnk_b=0.8364lnI-7.690, respectively. At 20 ℃, the apparent reaction rate constant of rosin was lnkb=1.204lnI-10.49. The initial quantum efficiency of abietic acid is 0.471 and the relationship between the activation energy (E_a) of abietic acid and the natural logarithm of the light intensity (lnI) is also linear: E_a=-7.549lnI+60.02.

The effect of carbon monoxide addition on soot formation in an acetylene/air premixed flame was investigated by detailed numerical simulation. This work focused on both the temperature effect and chemical effect of carbon monoxide addition on soot formation by comparing the results of flames with different CO contents. We find that the addition of carbon monoxide consistently reduces the formation of soot. The soot volume fraction and nucleation rate increase until a threshold temperature is reached and then decrease as the temperature increases. Considering that soot formation took place at the active site by H-abstraction mechanism, the addition of CO promotes the formation of soot. The concentration of H radicals increases and the concentration of OH radicals decreases because of the increased forward rate of the reaction OH+CO=CO₂+H. For soot formation to occur by the C-addition mechanism, the degradation rates of C₂H₂ tends to decrease and this promotes the formation of soot along with CO addition. On the other hand, the addition of CO may greatly reduce the volume fraction of C₂H₂ in fuel resulting in a lower surface growth rate.

Sub-micron LiNi_0.5Mn_1.5O₄ with excellent high rate performance was synthesized by a polyvinylpyrrolidone-assisted gel-combustion method. Thermogravimetric and differential thermal analyses (TG/DTA) were used to determine the nature of the combustion process of the gel. The structure and morphology of the as-prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and cyclic voltammetry (CV). The results showed that the LiNi_0.5Mn_1.5O₄ powders were single-phase spinel and consisted of uniform secondary particles (5 μm), which were formed by small primary particles (500 nm). Galvanostatic charge-discharge tests indicated that the LiNi_0.5Mn_1.5O₄ had an excellent rate capability and cyclic performance. When discharged at a rate of 0.5C, 1C, 4C, 8C,and 10C between 3.5 and 4.9 V, the discharge capacity is 131.9, 127.6, 123.4, 118.4, and 113.7 mAh·g^-1, respectively. Upon long cycling under a high discharge rate of 10C, the capacity retentions after 100, 500, and 1000 cycles were 91.4%, 80.9%, and 73.5%, respectively.

Using sodium citrate as a stabilizer, sodium borohydride as a reductant, 20%(w) Pt₆₀Ru₃₀Co₁₀/C catalyst was prepared by impregnating reduction. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the catalysts. We studied the catalytic activity and stability in a methanol solution at different pH values and pre-adsorbed CO monolayer stripping was used to investigate its anti-poisoning ability. The results showed that PtRuCo/C had the highest catalytic activity toward methanol at pH 8, and its catalytic activity and stability were much higher than that of commercial Pt₅₀Ru₅₀/C. Compared with Pt₅₀Ru₅₀/C, the pre-adsorbed CO monolayer oxidation potential showed a significant negative shift.

Thorn-like Pd nanoparticles (Pd_n^thorn000) were synthesized at room temperature by a reduction of PdCl₂ with L-ascorbic acid and with choline chloride as a stabilizer. Characterization of Pdthornn000 by transmission electron microscopy and cyclic voltammetry indicated that the synthesized Pdthornn000 has a relatively high density of surface step sites. By comparison with the commercially available Pd black catalyst, P_n^dthorn000 exhibits better catalytic activity towards ethanol oxidation. The oxidation current density on Pd_n^thorn000 was 1.2 times (-0.40 - -0.30 V) - 1.5 times (-0.65 - -0.40 V) as that on Pd black, and the onset potential and the peak potential of ethanol oxidation both shifted 50 mV in the negative direction. The oxidation potential of ethanol on Pdthornn000 is lower at the same current density.

To obtain low-Co AB₅ type hydrogen storage alloys with high discharge capacity and od cycling stability, the effects of substituting Cu with Fe on the phase structure and electrochemical performance of low-Co AB₅ type hydrogen storage alloys were investigated in detail. A series of low-Co type LaNi_3.55Mn_0.35Co_0.20Al_0.20Cu_0.85-xFe_x (x= 0.10, 0.20, 0.25, 0.40, 0.60) hydrogen storage alloys containin Cu and Fe were prepared by vacuum induction melting. X-ray diffraction (XRD) indicates that the alloys consist of a single LaNi₅ phase with a hexa nal CaCu₅ structure and the bulk phase structure of the alloy is not changed by the partial substitution of Fe for Cu. The parameters a, c, and the cell volume (V) increase with increasing Fe content. Electrochemical tests show that the maximum discharge capacity and the high rate dischargeability decrease but that the cycling stability of the alloy electrodes enhances significantly with increasing x. The capacity retention of the alloy electrodes at the 200th cycle (S₂₀₀) increases from 77.6% (x=0.10) to 89.9% (x=0.60). Substituting Cu with Fe enhances the cycle stability of the alloys because of an increase in cell volume which results in a lower expansion rate and a better anti-pulverization capability.

Activated carbon/manganese oxide (MnOx) composites were prepared by the thermal decomposition of Mn(NO₃)₂ that was impregnated on the surface of activated carbon XC-72 with a specific surface area of 250 m²·g^-1 and on YEC-8 with a specific surface area of 1726 m²·g^-1 at 200 ℃. The surface morphology and crystalline structure of the composites were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The electrochemical properties of the composites were tested by cyclic voltammetry, galvanostatic charge-discharge, and impedance spectroscopy. We found that α-Mn₂O₃ and α-Mn₃O₄ were formed when the composites were annealed at 200 ℃. At mass ratios of C and MnOx of 2∶1 and 9∶1, the specific capacitance of MnO_x in the composites of XC-72/MnO_x was 499 and 435 F·g^-1 and the specific capacitance of MnOx in the composites of YEC-8/MnO_x was 554 and 606 F·g^-1, respectively. This suggests a significant contribution of pseudocapacitance from MnOx to the specific capacitance of the electrode.

We present the synthesis, optical and electrochemical properties of three ethynyl-bridged ferrocenes with electron donor groups, Fc—C≡C—Ph-(p-OMe) (3a), Fc—C≡C—Ph-(p-NMe₂) (3b) and Fc—C≡C—Ph—(p-NPh₂) (3c). All three compounds show a Fe(II)Cp—C≡C—Ph—(p-R) (Cp=cyclopentadienyl) metal to ligand charge transition (MLCT) in 400-550 nm. Upon oxidation, 3a and 3c show a Cp—C≡C—Ph—(p-R)Fe(III) ligand to metal charge transition (LMCT) in the near-IR range (946 and 1044 nm). A reversible Fc⁺/Fc potential for 3a-3c and an irreversible Ph—NR⁺₂/Ph—NR₂ potential for 3b and 3c are observed by in the cyclic and differential pulse voltammetry. Finally, 3b shows an optical and electrochemical response upon protonation, with a red shift of the MLCT transition, an anodic shift of the Fc⁺/Fc potential, and disappearance of the Ph—NR⁺₂/Ph—NR₂ peak.

We synthesized a new imidazoline compound, 1-(2-amido-thioureaethyl)- 2-pentadecyl-imidazoline (IM-S). The corrosion inhibition performance and adsorption behavior for mild steel corrosion under H₂S and CO₂ coexistence were investigated by weight loss method, polarization curve, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results indicated that IM-S had excellent corrosion inhibition performance, and both cathodic and anodic processes of mild steel corrosion were suppressed. The highest inhibition efficiency was 92.74%. We found that the adsorption of IM-S on mild steel could be fitted to a Langmuir isotherm equation, and it belonged to a mix-type adsorption, which was mainly dominated by chemisorption. The relationship between the molecular structure of IM-S and the inhibition efficiency was investigated using quantum chemical calculations.

The influence of the alkaloid extract of Kopsia singapurensis on the corrosion behavior of mild steel (MS) in 1 mol·L^-1 HCl and 1 mol·L^-1 H₂SO₄ was studied using electrochemical techniques, viz., potentiodynamic polarization and AC impedance. The experimental results clearly show that the plant extract effectively inhibits corrosion in both acid media and the inhibition efficiency obtained from the electrochemical techniques is in od agreement. Furthermore, the polarization technique indicates that the extract acts as an anodic type inhibitor in HCl and as a mixed type in H₂SO₄. Scanning electron microscopy (SEM) was carried out to examine the surface morphological changes of metal specimens in both the inhibited and uninhibited solutions. SEM images show the formation of an adsorbed layer over the metal surface by the inhibitor molecule. The presence of alkaloidal constituents in the plant extract was confirmed by Fourier transform infrared (FTIR) spectroscopy and chemical analysis.

A novel strategy involving the combination of soft-templating and the solid-liquid method (CSSL) is presented for the synthesis of mesoporous nanocrystalline zirconia with a high specific surface area. The mesostructured zirconia hybrid is firstly synthesized by the soft-templating method using 1-hexadecyl-3-methylimidazolium bromide (C₁₆mim⁺Br^-) as the structure-directing agent and zirconium sulphate as an inorganic precursor. It is then ground in the presence of solid copper nitrate followed by heat-treatment in air. The resulting zirconia material, after calcination at 600 ℃, possesses a wormlike arrangement of mesopores surrounded by tetra nal ZrO₂ nanocrystallites of ca 2.50 nm diameter. The Brunauer-Emmett-Teller (BET) surface area is 240.0 m²·g^-1 and the pore size is 4.10 nm. However, no mesoporous structure exists in the obtained zirconia material that was produced using the simple soft-templating method at the same calcination temperature. The BET surface area is only 9.5 m²·g^-1 for this material.

The aim of this study was to determine the behaviors and mechanism of three hypercrosslinked polymers during the adsorption of nonylphenol ethoxylated decylether (NPEO-10) from aqueous solutions. The polymers were characterized to determine their specific surface areas, pore sizes, and elemental contents. The adsorption isotherms of NPEO-10 on the three polymers fit the Langmuir and double Langmuir models better than the Freundlich model, and the isotherm curves had similar shapes on a lg-lg scale. The amount of adsorbed NPEO-10 depends on the specific surface area, the pore size of the polymer, and the temperature of the solution. Thermodynamic analysis indicated that the adsorption process was characterized by an interaction of the hydrophobic part of the surfactant molecule with the surface of the polymer and by the formation of micelle-like aggregates on the surface of the polymer. A two-dimensional mixture consists of singly dispersed surfactant molecules and monolayered or bi-layered aggregates on the surface of the polymers. Adsorption dynamics confirmed that the adsorption process involved two plateaus which were related to the formation of a monolayer and a bi-layer. Finally, the elution processes were investigated to further establish the appropriate adsorption conditions for the purification of water containing NPEO-10.

Poly(N,N-diethylacrylamide-co-N-acryloxysuccinimide) (P(DEAM-co-NAS)) was synthesized by free radical solution polymerization and copolymerization ratios of 7.9∶1, 3.5∶1, 2.5∶1, 2∶1, 1.5∶1 were used. The copolymer structures were characterized by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance (¹H NMR). The copolymer compositions and the properties of the medium environment largely influence the temperature sensitivities of the P(DEAM-co-NAS) aqueous solutions. The lower critical solution temperature (LCST) of the P(DEAM-co-NAS) aqueous solution increased with an increase in the NAS content. The addition of salts resulted in a linear decrease in the LCST of the P(DEAM-co-NAS) aqueous solution and this depended on the anion valence of the salts. The addition of organic acids can reduce the LCST of the P(DEAM-co-NAS) aqueous solution. Moreover, the addition of NaOH, ethylenediamine, and putrescine leads to an increase in the LCST of the P(DEAM-co-NAS) aqueous solution. The effects of ethylenediamine and putrescine on the LCST of the P(DEAM-co-NAS) aqueous solution were greater than that of NaOH.

It is well known that DNA (including oli nucleotide) and cationic surfactant can form insoluble complex. In this study, by turbidity measurement and TEM image, we found that the single-chained cationic surfactant could transform the oli nucleotide/single-chained cationic surfactant precipitates into vesicles and the vesicles coexist with the insoluble complex. The hydrophobic interaction between the cationic surfactant and the precipitates plays a key role in vesicle formation. Moreover, when the temperature reaches a specific value where the oli nucleotide begins to melt, the oli nucleotide/single-chained cationic surfactant vesicles form far easier. Thus, the more extended the oli nucleotide, the much easier for vesicle formation. As far as we know, the study about the oli nucleotide/cationic surfactant vesicle formation is very limited. Therefore, considering the growing importance and significance of DNA (including oli nucleotide)/amphiphile systems in medicine, biology, pharmaceutics, and chemistry, this study should provide some helpful information in further understanding these systems.

The critical micelle concentration (cmc) and the concentration reducing 20 mN·m^-1 of water surface tension (pC₂₀) by the Gemini surfactant series (m-6-m) and the corresponding monomers (C_mTABr) were determined using surface tension measurements. Comparison between the active parameters indicates that the Gemini surfactants have a stronger micellization and adsorption ability than C_mTABr, which is attributed to the hydrophobic synergism between the alkyl tails of the Gemini surfactants. The effects of dissymmetry in the Gemini surfactants (12-6-m) on the micellization and adsorption were also discussed. The results showed that the Gemini surfactant with a symmetric structure is more effective in association and adsorption than that with a dissymmetric structure.

Surfactants p-octyl polyethylene glycol phenyl ether (Triton X-100) and bis(2-ethylhexyl)sulfosuccinate sodium salt (AOT) were mixed to prepare reverse micelles with n-hexane, n-hexanol, and water. The effects of surfactant mass ratio, concentration of co-surfactant, volume ratio of water to oil, and temperature on the conductivity of the reverse micelles were studied. The electrochemical behavior of potassium ferricyanide (K₃Fe(CN)₆)/potassium ferrocyanide (K₄Fe(CN)₆) in the mixed reverse micelles was investigated by cyclic voltammetry. The results indicate that the conductivity of the mixed reverse micelles is much higher than that of the single surfactant reverse micelles and it changes with the surfactant mass ratio w (w=m_AOT∶m_{Triton X-100}). When w changed from 0 to 0.4, the conductivity σ increased linearly. The conductivity then increased slowly and stabilized at 576 μS·cm^-1 when w was 0.96. Simultaneously, the increase in water content and temperature enhanced the conductivity while the addition of co-surfactant decreased the conductivity obviously. In the mixed micelle system, the redox peak potentials of Fe(CN)^3-₆ /Fe(CN)^4-₆ were almost constant with a change in scan rate, and the redox potential gaps were about 75 mV. Furthermore, the ratio of the redox peak current for all scan rates was close to 1. The oxidation peak current increased linearly with the square root of scan rate. The results indicate that the Fe(CN)^3-₆ /Fe(CN)^4-₆ electrochemical reaction is reversible and is controlled by diffusion in the mixed reverse micelle system.

A theoretical study on the surface potential of alkanethiol self-assembled monolayers (SAMs) with different alkyl chain lengths on a ld substrate was carried out in terms of the Helmholtz model. The influences of molecular dipole moment, relative permittivity of the SAMs, and angle between the molecular chain and the substrate normal on the surface potential were systematically investigated using quantum chemical softwares Gaussian 03 and MOPAC. We found that the variation of surface potentials for the alkanethiol SAMs with different alkyl chain lengths mainly resulted from regular changes in the angles between the molecular chains and the substrate normal. We propose a new explanation for the variation in surface potentials of the alkanethiol SAMs with different alkyl chain lengths by considering the SAM formation mechanism.

Carboxyl functionalized SBA-15 type mesoporous molecular sieves synthesized via co-condensation process were characterized by small-angle X-ray scattering (SAXS). Correlation function and chord length distribution theory were used to analyze the pore structure, interface, and periodic information. The pore structure parameters calculated from chord length distribution theory were compared with the Barrett-Joyner-Halenda (BJH) model cal-culation results, which are based on conventional nitrogen adsorption-desorption tests. The results showed that the samples preserved the structure order of their mesostructures since no significant degradation occurred with an increase in carboxyl group loading, except for the samples with a high carboxyl loading of 50% (molar fraction, versus inorganic silica source). There are no significant deviations in the porod curves of all of the samples. The carboxyl groups may become internally embedded within the framework walls of the mesostructure, as opposed to being externally linked to the pore channels via condensation on surface Si—OH sites. Individual pore size and pore wall thickness distribution data were obtained from the chord length distribution theory calculation without modeling. The pore wall thickness distribution data, which are inaccessible by other method, are very helpful for a further understanding of the mesostructure materials.

The addition of sodium phosphate monobasic (NaH₂PO₄) to a synthetic mixture allows a one-step synthesis of mesoporous Beta zeolite. Aggregation of the nanosized Beta zeolites allows the filtration difficulties to be overcome while the intercrystalline mesopores reduce the diffusion limitation and thus enhance the catalytic activity. The obtained Beta zeolite samples were characterized by X-ray diffraction, scanning electron microscopy, N₂ adsorption-desorption, and temperature-programmed desorption of ammonia. The amount of phosphate strongly influenced the mesopore volume of the Beta zeolites. When the molar ratio of NaH₂PO₄/SiO₂ was 0.1, the sample had od textural and acidic properties and exhibited the best catalytic activity for the alkylation of phenol with tert-butanol.

Highly active and stable Pt-SO^2-₄ /ZrO₂-Al₂O₃ solid superacid catalysts were prepared by simultaneously introducing appropriate amounts of Pt and Al2O3 into a SO^2-₄ /ZrO₂ catalyst. The effect of Al content on the performance of the catalysts was studied using n-pentane isomerization as a probe reaction and the catalysts were characterized by X-ray diffraction (XRD), specific surface area measurements (BET), infrared (IR) spectroscopy, temperature-programmed reduction (TPR), thermogravimetry-differential thermal analysis (TG-DTA), and NH₃ temperature-programmed desorption (NH₃-TPD). The results show that Al can increase the crystallization temperature of ZrO₂ and inhibit the decomposition of sulfur. Al can also increase the surface area of the catalyst, strengthen the combination between S and O, improve the redox performance of the catalyst and increase the acid strength and the acidity of the catalyst. The catalytic activity of the Pt-SO^2-₄ /ZrO₂-Al₂O₃ solid superacid catalyst with a Al₂O₃ mass fraction of 5.0% was found to be the best. The isopentane yield was stable above 52.0% and the selectivity was higher than 98.2% within 100 h.

Novel chromium-free Cu-Al-Ba catalysts were prepared by co-precipitation and were calcined at different temperatures. Their performance during the hydrogenation of palm oil esters to higher alcohols was evaluated in an autoclave. Results showed that the catalytic properties of the catalysts were greatly influenced by the calcination temperatures. The yield of higher alcohols showed three steps when the calcination temperature of the catalysts was raised from 150 to 750 ℃. The thermogravimetric (TG-DTG) curves of the precursor also exhibited three steps related to mass loss. X-ray power diffraction (XRD), X-ray fluorescence (XRF), transmission electron microscopy-energy dispersive spectrometry-selected area electron diffraction (TEM-EDS-SAED), N₂-physisorption, and temperature- programmed reduction (TPR) characterization revealed that the catalysts were obtained from a malachite-boehmite-BaCO₃ precursor. After calcination at 300 or 550 ℃, the catalysts were found to be composed of crystalline CuO and BaCO₃ as well as amorphous Al₂O₃. Amorphous Al₂O₃ has a large surface area which results in a high dispersion of CuO. Rod-like BaCO₃ helps in the provision of micropores. The formation of BaAl₂O₄ at a calcination temperature of 750 ℃ destroys the amorphous structure and causes a sharp decline in the surface area and pore volume of the catalyst and this causes CuO aggregation. An optimal higher alcohol yield of 92.3% was obtained over the Cu-Al-Ba catalyst that was calcined at 550 ℃ due to its larger surface area, larger pore volume, and higher degree of CuO dispersion.

A series of nanoscale HZSM-5 zeolites modified with different amounts (0-8%, w) of magnesium were prepared by an impregnation method and characterized by X-ray diffraction (XRD), Al solid state magic angle spinning nuclear magnetic resonance (²⁷Al MAS NMR), N₂-adsorption/desorption, temperature-programmed desorption of NH₃ (NH₃-TPD), and pyridine adsorption Fourier transform infrared (FT-IR) methods. The conversion of methanol to propylene was tested in a continuous flow fixed-bed microreactor at atmospheric pressure, 500 ℃, and a methanol space velocity (WHSV) of 1.0 h^-1. The results indicated that with an increase in the amount of Mg, the selectivity of propylene and butene increased but those of methane, ethylene and aromatics decreased consistently. With an increase in the amount of Mg the stability of the catalyst was found to increase initially, pass through a maximum at 2% and then decrease with higher amounts of Mg. The effect of modification with magnesium oxide on the catalytic performance of the nanoscale HZSM-5 zeolite for the conversion of methanol to propylene can be attributed to the resultant changes in acidity and texture of the modified nanoscale HZSM-5 zeolites.

The complete oxidation of ethanol (COE) was studied over Cu_0.1Ce_0.9O_x and Cu_0.1Ce_0.6Zr_0.3O_x catalysts prepared by the sol-gel method. Samples were characterized by X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET) adsorption, Raman spectroscopy, hydrogen temperature-programmed reduction (H₂-TPR), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). Results show that for fresh samples, the activity of COE is found to be superior over Cu_0.1Ce_0.9O_x than over Cu_0.1Ce_0.6Zr_0.3O_x whereas this is reversed for aged samples. The thermal stability improves after the introduction of Zr. Furthermore, the relationship between the active species and the activity for COE was investigated.

A novel process to prepare well-dispersed Pt nanoparticles on poly(N-acetylaniline) functionalized multiwalled carbon nanotubes (Pt/PAANI-MWCNTs) using chemical in situ polymerization and reduction is reported. Scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), UV-Vis absorption spectroscopy as well as Raman spectroscopy were used to characterize the catalyst. We found that PAANI can easily immobilize onto the MWCNTs because of a strong interaction with the basal plane of graphite via π-stacking. The Pt particles supported on the PAANI-MWCNTs are uniformly dispersed with a narrow particle size distribution. The electrocatalytic activity of the Pt/PAANI-MWCNTs towards the oxidation of methanol was investigated using cyclic voltammetry and chronoamperometry. The results indicate that the Pt/PAANI-MWCNTs catalysts exhibit higher electrocatalytic activity, better anti-poisoning ability, and od stability during methanol oxidation in comparison to the Pt/MWCNTs for acid oxidation (Pt/AO-MWCNTs).

Visible-light photoactive Ag/TiO2 catalysts were successfully prepared by a solvothermal method. The samples were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption isotherm (BET), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-visible (UV-Vis) spectroscopy. The photodegradation of methylene blue (MB) solution was used to evaluate the photocatalytic activity of the catalyst under UV and visible light irradiation (λ>400 nm). XRD results showed that the TiO₂ was in the pure anatase phase. Ag nanoparticles were loaded onto the TiO₂ nanoparticle surface and this had little influence on the crystal phase and the particle size of TiO₂. The specific surface area of the samples was far higher than that for the samples prepared by the sol-gel method and the sample with Ag molar fraction of 5% had the highest value of 151.44 m²·g^-1. The absorption spectrum of the Ag-modified TiO₂ increased greatly and the adsorption edge was extended into the visible region. The photodegradation of MB solution followed a pseudo-first-order kinetic expression. The photocatalytic activities of the Ag/TiO₂ composites prepared by the solvothermal method were remarkably higher than those prepared by the sol-gel method. Under UV or visible light irradiation, the optimal photoactivity was obtained for the sample with a Ag molar fraction of 5%.

We report on density functional theory (DFT) total-energy calculations within the generalized gradient approximation for the adsorption of hydrogen onto Be(0001) surface. To investigate the atomic geometries and stability with different hydrogen coverages for this system, we changed the atomic hydrogen coverage from 0.06 to 1.33 monolayer (ML) using various surface supercell geometries. The calculations showed that the adsorption sites have a strong dependence on hydrogen coverage. The adsorbates mainly occupied fcc and hcp hollow sites below 0.67 ML. At 0.78 ML the hydrogen atoms were adsorbed on hollow and bridge sites while for the higher coverage range (ca 0.89-1.00 ML) the hydrogen atoms were adsorbed onto the tilted bridge sites, i.e., a bridge site with a small deviation towards the hollow position. From 1.11 to 1.33 ML, the adsorbed hydrogen atoms were located at hcp and bridge sites, and some Be surface atoms were expanded. All these adsorption configurations were found to be energetically favorable with a H₂ reference point fixed on H2 molecule. Further total-energy calculations based on a p(3×3) geometry did not revealed any stable or energetically favorable adsorption geometry versus the H2 molecule beyond a hydrogen coverage of 1.33 ML.

A series of covalently bound albumin (bovine serum albumin (BSA) and human serum albumin (HSA)) conjugates of phthalocyanines functionalized with carboxyls were prepared and resulted in amide bonds. The phthalocyanines are tetra-α-(4-carboxyl phenoxy) phthalocyanine zinc (1) and tetra-α-[4-(2-carboxyl-ethyl) phenoxy] phthalocyanine zinc (3) as well as their corresponding tetra-β-substituted counterparts (compounds 2 and 4). The spectroscopic properties of these phthalocyanines and their bioconjugates in phosphate buffer saline solution (PBS) were investigated. The phthalocyanines that are covalently bound to the albumins have a more obvious monomeric absorption characteristic than the corresponding free phthalocyanines. Moreover, the spectroscopic characteristics of the phthalocyanines in the bioconjugates are not affected by solution pH. The substitution position of the carboxyl moieties on the phthalocyanine ring has an effect on the spectroscopic transformation of these macromolecules after conjugation with the albumins. Substitution at the α-position of the phthalocyanine ring leads to more prominent spectroscopic changes than that at the β-position. Both 1-albumin and 3-albumin in PBS show monomeric phthalocyanine spectra with Q-band maxima at about 697 nm and 706 nm, respectively.

Steady state fluorescence and fluorescence decay of a series of monosubstituted biphenyl containing side- chain liquid crystalline polyacetylenes with different lengths of spacers were investigated. For comparison, a monomer was selected as a model compound. Steady state fluorescence spectra elucidated that the polymers and the monomer showed single fluorescence emission arising from the biphenyl group on the side chain. With decreasing the length of the spacer, the fluorescence intensity of the polymer decreased accordingly. The fluorescence decay showed that the decay of the monomer could be fitted to be a single-exponential decay, while that of the polymers should be fitted to be a triple-exponential decay, which may be originated from the local high concentration induced quenching and the rotational restriction of the side-chain biphenyl groups. Solvent effects illustrated that the interaction between the solvents and the biphenyl groups strengthened with increasing the polarity of the solvents.

Intermolecular complexes of silicane with AB-type interhalogen compounds (ClF, BrF, IF, ICl, IBr, BrCl) were examined using ab initio calculations performed at the second-order MΦller-Plesset perturbation approximation with the 6-311++G(3d,3p) basis set. Frequency calculations were also run using the same level of theory. Inverse hydrogen bonds were formed in the complexes of silicane with AB-type interhalogen compounds as determined by the geometrical criteria and the natural bond orbital (NBO) net charge transfer number as well as the molecular graphs. The calculated binding energies of the complexes using MP2/6-311++G(3d,3p) methods and corrected by the basis-set superposition error (BSSE) were -5.113 to -9.468 kJ·mol^-1. Decomposition of the interaction energies was carried out using symmetry adapted perturbation theory (SAPT). The results indicate that the contribution of the induction energy to the total attractive energy ranges from 55.0% to 72.2%, which are the primary contribution to the total attractive energy. The contribution of electrostatic energy and dispersion energy to the total attractive energy are less than 25.0%.

The molecular geometries, electronic structures, reorganization energies, and charge transfer integrals of three anthracene derivatives {2,6-bis[2-(4-pentylphenyl)vinyl]anthracene, DPPVAnt; 2,6-bis-thiophene anthracene, DTAnt; 2,6-bis[2-hexylthiophene]anthracene, DHTAnt} were investigated by density functional theory at the B3LYP/6-31G(d) level. Their mobilities at room temperature were estimated using Einstein relations and compared with the calculated mobility of anthracene. DPPVAnt is a od hole-transporting material with a hole mobility as high as 0.49 cm2·V^-1·s^-1; DHTAnt is an electron-transporting material with an electron mobility of about 0.12 cm2·V^-1·s^-1; DTAnt is a bipolar material with its hole and electron mobilities being 0.069 and 0.060 cm2·V^-1·s^-1, respectively. The calculated mobilities were of the same magnitude as those obtained by experimental measurements. The reorganization energies for the electrons of the three derivatives are almost the same as that for anthracene but the reorganization energies for the holes of the three derivatives are larger than that of anthracene and they follow the order: anthracene

Density functional theory within the generalized gradient approximation (GGA) was used to investigate the electronic structures and optical properties of the BeO crystal in wurtzite (WZ), zinc blende (ZB), and rocksalt (RS) phases under high pressure. Results indicated that with an increase in pressure for all three structures, the BeO bond became shorter, the charge transfer decreased, the conduction band shifted to higher energy and consequently the width of bandgap became wider. Compared to BeO at 0 GPa, the curves of the dielectric functions, absorption coefficients, and electron energy-loss functions of the three high pressure phases showed finer structures. With an increase in pressure, the absorption coefficient spectra and the energy-loss functions expanded while the absorption edges and the absorption peaks of the absorption curves as well as the peaks of the energy-loss functions showed a blue shift to some extent.

Mn doped SnO₂ one-dimensional nanostructures (nanowires and nanobelts) were fabricated using catalyst assisted chemical vapor deposition (CVD). X-ray diffraction revealed a rutile structure of SnO₂ in all the products. The morphology and the growth mechanism of the products were sensitive to the fabrication temperature and the concentration of the gaseous source materials. The growth mechanisms of the nanowires and nanobelts can be ascribed to vapor-liquid-solid (VLS) and vapor-solid (VS) processes, respectively. Four new peaks appeared at 500, 543, 694, and 720 cm^-1 in the Raman spectra were attributed to the active infrared mode and the surface mode. A photolumines-cence peak was observed at 520 nm and the intensity of the peak was closely dependent on the concentration of oxygen vacancies.

Hydrogenated amorphous silicon carbide (a-Si_1-xC_x:H) films were prepared by microwave electron cyclotron resonance (MW-ECR) plasma enhanced unbalance magnetron sputtering with a silicon target and CH₄ as Si and C sources, respectively. The influence of CH₄ flow rate and the deposition temperature on the chemical structure, stoichiometry, and hardness were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and nano-indentation. The results indicated that, as the CH4 flow rate increased from 5 to 45 cm³·min^-1 (standard state), the amount of Si—CH₂ groups and C—H groups increased constantly, but the number of Si—H groups did not change. The atomic concentration of C increases from 28% to 76% while Si decreases from 62% to 19%. The amount of Si—H and C—H groups in the deposited films decreases dramatically while the Si—C bonds and the hardness of the resultant films increase with an increase in deposition temperature at a constant CH4 flow rate. The atomic concentrations of Si and C remain almost constant at about 52% and 43%, respectively. The hardness of the deposited films with a constant CH₄ flow rate of 15 cm³·min^-1 increases to 29.7 GPa at a deposition temperature of 600 ℃. We propose a growth mechanism for the a-Si_1-xC_x:H films at room temperature (25 ℃) and at high temperature based on the characterization results.

Undoped TiO₂ and Cu-doped TiO₂ (Cu-TiO₂) nano-structured thin films were prepared by a sol-gel process on glass substrates. We investigated their structures, surface morphologies, and tribological properties by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray diffraction (XRD), and friction and wear testing using a UMT-3 tester. We found that the prepared Cu-TiO₂ films were smoother and more uniform than the undoped TiO₂ films and they had better friction-reducing and anti-wear properties. The amount of Cu dopant directly affects the tribological performance of the doped TiO₂ film. The 5%(mole fraction) Cu-TiO₂ film possesses the longest wear life and the lowest friction coefficient.