Au@Pt core-shell nanoparticles were successfully synthesized via the seed-mediate growth method and were self-assembled to be a monolayer film at the water/hexane interface. After being carefully transferred onto a glassy carbon (GC) electrode, a monolayer film electrode was fabricated with high Au@Pt surface-to-volume ratio. It was found that good dispersion of Au@Pt core-shell nanoparticles on the surface of GC electrode was achieved, resulting in the uniform monolayer film electrode. It was resulted that the as-prepared monolayer film electrode exhibited high electrocatalytic activity for methanol oxidation. Moreover, the monolayer film exhibited excellent surface enhanced Raman spectroscopic (SERS) activity due to the long-range enhancement effect from the Au nanoparticles core, which was well recognized as a good SERS substrate. Therefore, it can be served as a SERS substrate for investigating the surface adsorption and reactions at the molecular level. According to these advantages of the monolayer film electrode, the reaction process of methanol oxidation was monitored by in situ SERS detection via combining the strong SERS activity and the high electrocatalytic activity of the monolayer film electrode. The data supplies the basis on analyzing the mechanism of methanol oxidation on Au@Pt film/GC electrode.

Extraction and derivatization in single drop (EDSD) coupled to matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS) was utilized to determine small molecular aldehydes in single puff smoke. Through employing Girard's reagent T as derivatization reagent, small molecular aldehydes (SMAs) transformed into quaternary ammonium salt, and the sensitivity of analysis for SMAs was significantly improved. Using this method, acetaldehyde and acrolein in single puff smoke were easily determined. This approach with an automatic potential provided a simple, rapid, and accurate procedure for the determination of SMAs in smoke.

Density functional calculations with UB3LYP functional and an extended ECP basis set are employed to Calculate the geometries and energies for all possible reactants, intermediates, transition states and products on sextet, quartet and doublet surfaces in four pathways of addition (oxidative addition and [2+2]cycloaddition)-elimination, abstraction-rebound and oxene-insertion for investigating the mechanisms of oxidative activation of dihydrogen by osmium oxide cation. From the results calculated, the titled reaction is spin-forbidden, which starts on the quartet surface and ends on sextet surface, the overall reaction is exothermic by 21.0 kJ·mol^-1. Oxene-insertion process is unfavorable thermodynamically due to more positive Gibbs free energy for the reactant complexes. The other three mechanisms proposed exhibit multiple-state-reactivity (MSR) or two-state-reactivity (TSR). Individually the surfaces in three spin states for the two addition-elimination pathways may cross over three times, while the sextet and quartet surfaces for abstraction-rebound may cross once, respectively. The abstraction-rebound mechanism starts on the H-abstraction process with uphill potential surfaces and high endothermicity, followed by a barrierless and highly exothermic rebound of H atom, thus it cannot take place at normal temperature. While the two addition-elimination processes have the same rate-determining step, where each barrier is about 156.9 kJ·mol^-1,which is a little higher than that for the usual reactions in liquid, however it is possible to take place due to coupling with the highly exothermic steps before. Furthermore, the concerted [2+2] cycloaddition step has a lower barrier of only 28.7 kJ·mol^-1, which is 113.7 kJ·mol^-1 lower than that for the step of the reductive elimination of the first hydride in oxidative addition-elimination process. Thus, [2+2] cycloaddition process is more favorable than oxidative addition process kinetically.

The structures of 2-(3'-hydroxy-2'-pyridyl)benzoxazole (HPyBO) with alkali (or alkaline earth) metal ions (Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺ and Ca²⁺) were fully optimized at the 6-311++G(d,p) level by using B3LYP density functional theory and the binding energies were calculated at the same level. The result shows that the cation-π interaction between alkali (or alkaline earth) metal ions and HPyBO complexes are very strong, some of the interactions are even comparable to chemical bonding. The relative energies show that cation-π interaction can change the energy barrier of intramolecular proton transfer. When considering the solvent effect of water, the relative energies of isomers and the energy barrier of intramolecular proton transfer are changed to some extent. In addition, the properties at the BCPs (bond critical points) of intramolecular hydrogen bond in the complexes are also discussed.

A novel chiral stationary phase was synthesized via the combination of atom transfer radical polymerization (ATRP) and click chemistry. In the synthesis, the silane coupling agent 3-(2-bromoisobutyryl)- propyl triethoxysilane (BPE) was chosen as the ATRP initiator and immobized on the porous silica gel. The polymer chains of poly(2-methyl-3-butyn-2-ol methacrylate) (pMBMA) were grafted on the silica substrates by surface-initiated ATRP. This “grafting-from” technique was used to synthesize polymers with controllable molecular weight and narrow molecular weight distributions. For immobilizing the chiral selector, azide-modified β-cyclodextrin (β-CD) was synthesized and bounded on the pMBMA by click chemistry, which can avoid the side-reactions in the preparation. The materials with different pMBMA chain density and length on the silica gel surface were prepared. Several pharmaceuticals were used to evaluate the enantioseparation ability of the materials under reversed-phase high performance liquid chromatography. The results demonstrate that ATRP can well design the polymer structure, and click chemistry can provide an effective route in the β-CD immobilization for chiral discrimination. It was found that the retention and separation factors of chiral compounds could be improved by adjusting the pMBMA chain density and length on the surface of silica gel.

Silver doped hydroxyapatite (HA) antimicrobial powders were synthesized by hydrothermal method using Ca(NO₃)₂?4H₂O, AgNO₃, (NH₄)₂HPO₄ as raw materials. The effects of addition of AgNO₃, reactive temperature and time on the microstructure and constituent of Ag-HA were investigated. The XRD patterns indicate that HA and Ag-HA have the same crystal structure. The calculation results of energy dispersive spectrometer (EDS) and X-ray fluorescence spectrum (XRF) indicate that Ca²⁺ in HA crystals is displaced by Ag⁺ and Ag_xCa_10－x(PO₄)₆(OH)₂ was produced at hydrothermal condition. The antibacterial test results indicate that Ag-HA have favourable antibiotic property and MIC≤50 μg/mL against Escherichia coli and Staphylococcus aureus.

The recent development of new gold(I) catalytic methods has opened the door to the total synthesis of natural products and bioactive complex molecules. We describe a convenient, straightforward, efficient and environmentally benign protocol to synthesize the 5-(3-indolyl)oxazole. The new synthetic route was finished in five steps including iodization, N-Boc protection, Sonogashira cross-coupling, gold catalyzed reaction, deprotection using indole as the starting material. The key step was generation of α-oxo carbene via gold-catalyzed intermolecular oxidation of alkynes (2).

The time development of morphologies and structures of symmetric and asymmetric polystyrene- b-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer thin films after annealing in acetone vapor was investigated by tapping mode atomic force microscopy (AFM). Film thickness played an important role in the morphology evolution of symmetric PS-b-PMMA (f_PS≈f_PMMA, f_PS is the volume fraction of the PS in PS-b-PMMA, f_PMMA is the volume fraction of the PMMA) thin film. When film thickness was controlled according to their equilibrium bulk lamellar period, all the investigated thin films of PS-b-PMMA with different molecular weights can change from disordered pattern to nanoscale depression and at last to striped structures. In the case of asymmetric PS-b-PMMA systems, when the content of PS segment was low (25%, 36%), film morphology changed from disordered state to regularly packed spheres and directly to stripes, respectively; when the content of PS segment was high (70%), film morphology changed from disordered pattern to relatively flat state. The formation mechanisms of different film morphologies have been discussed in detail.

Interaction of Sunset yellow (SY) and β-carotene (BC) with bovine serum albumin (BSA) was investigated under simulated physiological conditions by spectroscopic approaches (fluorescence, UV-Vis, FT-IR and CD). Both SY and BC quenched the intrinsic fluorescence of BSA through static quenching mechanism. The thermodynamic parameters (DH, DS, and DG) obtained from the fluorescence data measured at three different temperatures indicated that the binding of SY to BSA involved electrostatic force, and that of BC to BSA mainly by hydrogen bonding and van der Waals forces. The binding sites number n and binding constants K_a were also obtained. The result of FT-IR spectra and CD showed that the binding of SY to BSA induced conformational changes in BSA.

A new cationic host molecule was synthesized by reaction of the di-amide based macrocycle with methyl iodide and the structure was confirmed by NMR, ESI-MS spectra. The complexation behavior of the di-amide based macrocycles with pyridine N-oxide guests was investigated by means of ESI-MS and ¹H NMR. The results showed that the cationic host can not only bind the pyridine N-oxide hosts to form 1∶ 1 pseudorotaxane-like complexes but also have much stronger binding ability than the corresponding neutral hosts.

PEG4000-based polymer nanocomposites filled with a series of PEG functionalized graphene (GO-PEG) have been prepared by solvent blending. The structure and properties of these nanocomposites could be studied by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TG) in detail. The results indicate that functionalized graphene is dispersed on a molecular scale and the corresponding composites show the layer-aligned structures. The thermal stability of polymer nanocomposites could be improved significantly by the strong interfacial interactions between both components mainly. At last, the schematic illustration of the synthesis of layer-aligned polymer nanocomposites has been provided.

We report herein a new guanine sensor for the determination of guanine based on a photoelectrochemical effect of poly(thionine) photoelectrode to hydrogen peroxide (H₂O₂). The photoelectrode was fabricated by electropolymerizing thionine on the surface of ITO electrode. And then xanthine oxidase was immobilized on the photoelectrode via the aid of chitosan enwrapping, forming an enzyme-modified photoelectrode. The photoelectrode was employed as an electron acceptor, and H₂O₂ from the catalytic reaction of enzyme was employed as an electron donor, the guanine can be detected due to photoelectrochemical effect between photoelectrode and H₂O₂. In the paper, photoelectrochemical effects of photoelectrode to H₂O₂ and guanine were studied. Effects of bias voltage, illumination intensity and electrolyte pH on the photocurrent were investigated. The linear response of guanine concentrations ranged from 1.00～200 μmol/L was obtained with a detection limit of 0.55 μmol/L. The guanine sensor was successfully applied to detect the disorganization of DNA mediated by heating acid solution and active ingredient of aciclovir. The relative standard deviation (RSD) was less than 5.37% and the recovery was in the range of 96.8%～106% for the determination of samples. The preparation of the sensor and the detection of guanine have the advantages of economy and simpleness due to without peroxidase and deoxygenated.

A novel borosilazane monomer terminated with Si-Cl groups: B,B',B"-tris[(trichlorosilyl)- methyl] borazine (TSMB) was synthesized through one-step route by reacting boron trichloride (BCl₃), chloromethyl trichlorosilane (CH₂ClSiCl₃) with hexamethyldisilazane (HMDZ) as the starting materials. From functionalizing TSMB by 2-hydroxethyl acrylate and 2-hydroxyethyl vinyl ether, two UV-curable single source precursors a-TSMB and e-TSMB were obtained, respectively. Then ceramic materials C1 and C2 can be prepared with a-TSMB and e-TSMB through UV-curing and cracking under 1400 ℃ for 2 h. The chemical composition, structure, photo-curing performance and ceramic yield of the TSMB, a-TSMB and e-TSMB were investigated using infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), differential photocalorimetry (DPC), real time infrared spectroscopy (RT-IR) and thermo gravimetric analyzer (TGA). The content and high temperature performance of the ceramic C1 and C2 were studied by element analysis, X-ray photoelectron spectroscopy analysis (XPS) and X-ray diffraction (XRD). Results show that both the two ceramic precursors molecules, a-TSMB and e-TSMB, contain the B-N six-member ring structure, and are terminated with acrylate or vinyl ether functional groups, which matches well with the theoretical design. The photo polymerization of the a-TSMB and e-TSMB can finish 82% and 67% in 25 s, the final conversion of the double bond can reach 90.0% and 74.0%, and the corresponding ceramic yield at 1300 ℃ is 57.9% and 48.5%, respectively. There are five elements, Si, B, C, N, and O in the C1 and C2 ceramic materials, and the contents of B are 4.4% and 4.9%, respectively, which can achieve the requirement for the high temperature ceramic material on the B element. Both the ceramic materials C1 and C2 can preserve amorphous states at 1400 ℃ and have excellent high-temperature resistance properties.

Mg-Al hydrotalcite-like compound (HTlc), calcined HTlc (CHTlc) and dodecylsulfate anionintercalated Mg-Al HTlc (DS·HTlc) were prepared. The sorption behavior of o-cresol on the HTlc, CHTlc and DS·HTlc was investigated. The sorption kinetics and sorption isotherms of o-cresol on the HTlc, CHTlc and DS·HTlc can all be well fitted with the pseudo-second order kinetic and Freundlich equation, respectively. The results indicated that the sorption rate and sorption amount of o-cresol on the DS·HTlc is much higher than that on the CHTlc, which is little higher than that on the HTlc. The sorption amount of o-cresol on the HTlc and CHTlc increased firstly and then decreased with increasing pH in the initial pH range of 5.00～13.00 and increased with increasing temperature. The sorption amount of o-cresol on the DS·HTlc decreased gradually with increasing initial pH and temperature. The sorption amount of o-cresol on the HTlc, CHTlc and DS·HTlc increased with the increasing electrolyte (NaCl) concentration. The sorption mechanism was discussed in detail and the DS·HTlc will be a new kind of highly effective adsorbent for phenolic pollution.

CdS-pillared K₂La₂Ti₃O₁₀ photocatalysts were synthesized via ion-exchange reaction, butylamine pillaring and sulfuration processes under the assistance of the microwave irradiation. The structure of the photocatalysts was determined by means of powder X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet-visible diffuse reflection spectra (UV-Vis). The photocatalytic activities of these composite compounds for hydrogen production were also investigated under UV and visible light irradiation. The results revealed that the CdS-pillared K₂La₂Ti₃O₁₀ photocatalysts prepared under the assistance of microwave irradiation possess the similar crystal structures with that prepared via a traditional waterlogging method. At the same time, microwave irradiation can greatly decrease the preparation time, resulting in less destruction of the layered structure and improve the absorption for visible light. The photocatalytic activities for hydrogen production of the CdS-pillared K₂La₂Ti₃O₁₀ photocatalyst prepared via a microwave assisted procedure were 221.53 mmol/(g cat.) and 3.23 mmol/(g cat.) under UV light and visible light irradiation, respectively, after 3 h irradiation. At last, the photocatalysis mechanism was deduced.

The effects of chemical substitution on the ground and excited state intramolecular proton transfer (ESIPT) of 2-(2'-aminophenyl)benzimidazole (APBI) have been theoretically studied when a hydrogen atom of the amino group was replaced by CH₃ (E-C), SiH₃ (E-OSi), NH₂ (E-N), COH (E-CO), NO₂ (E-NO₂), CF₃ (E-F), CN (E-CN₃), OMe (E-OMe), COCH₃ (E-CC), Ts (E-S), p-CH₃C₆H₄CO (E-C＝O) and p-CH₃C₆H₄NHCO (E-NH). The results show that in ground state the most stable configuration is the enolic form E; sub-stable configuration is the rotational isomer R. The keto form K only exists in the ground state when substituents is E-CN₃, E-F, E-NO₂, E-N or E-OMe. The results of nucleus independent chemical shifts (NICS) show that substituents affect electron delocalization of the APBI ring. Excited state proton transfer potential energy surface studies have shown that intramolecular proton transfer of all the derivatives could occur in excited state. The ESIPT of the APBI is barrierless process in S₁ state when introducing the substituents E-CN₃, E-N, or E-OMe. There is almost no effect on ESIPT when introducing the substituents E-C,E-C＝O or E-OSi. The K^* configuration become more stable than E^* in S₁ state when substitutent is E-CC, E-NH, E-CO, E-F, E-NO₂, or E-S.

Binodal data for the 1-ethyl-3-methylimidazolium dimethyl phosphate ([Emim]DMP)+salt (K₃PO₄, K₂HPO₄, and K₂CO₃)+H₂O systems were experimentally determined at 298.15 K. Three empirical equations were used to correlate binodal data. The Merchuk equation is an uncomplicated one for fine accuracy. The ability of different salts studied for phase separation are in the order of K₃PO₄>K₂HPO₄>K₂CO₃, which may be related to the Gibbs free energy of hydration of the ions (Δ_hydG). The reliability of the calculation method and the corresponding tie-line data was described by the Othmer-Tobias equation and Bancroft equation, as well as the two-parameter equation. [Emim]DMP is a familiar ionic liquid, which is extensively used for extractive desulfurization of fuel oils. This is the first time to report the data for phase diagrams of [Emim]DMP+salt+water systems.

Silk fibroin (SF) films were prepared using a casting method and the structural change owing to treatment with methanol-water mixtures of different concentrations was investigated by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results were used to reveal the influence of structure on the release dynamics of Rhodamine B, a model compound loaded in the SF matrix. In methanol concentration ranging from 50% to 90%, the content of silk Ⅱ crystalline structure, constituted by β-sheet, first increased and then decreased with increasing methanol concentration in the mixtures, reaching a maximum around 80%. It was found that Rhodamine B released from the SF film via Fickian mechanism, of which the diffusional exponent increased with increasing β-sheet content in the matrix, suggesting that the silk Ⅱ crystal could be used as natural regulator for drug release from SF material.

The synthesis mechanism of 3-octylthien-2,5-ylenediethynylene-co-benzo[c]-1',2',5'-thiadiazo- 3,6-ylenedi(2,5-thienylene) with PdCl₂(PPh₃)₂-catalyzed is investigated by density functional theory (DFT) at the GGA/PW91/DNP level. The geometric configurations of reactants, intermediates, transition states, and products are optimized. The energy analysis calculation approves the authenticity of intermediates and transition states. Additionally, the synthesis mechanism of 3-octylthien-2,5-ylenediethynylene-co-benzo[c]- 1',2',5'-thiadiazo-3,6-ylenedi(2,5-thienylene) without PdCl₂(PPh₃)₂-catalyzed is studied employing the same functional and basis set. The computational results show that the activation barrier with PdCl₂(PPh₃)₂- catalyzed is lower than the activation barrier without PdCl₂(PPh₃)₂-catalyzed, which demonstrates that the catalyst of PdCl₂(PPh₃)₂ possesses catalytic activity. Moreover, the density functional theory and periodic slab model are used to investigate the product (P) adsorption on TiO₂(100) surface. The Mulliken charge and frontier orbital of the TiO₂(100)-P are also discussed. The results reveal that the charge of 0.692 e transfers from the P to the TiO₂(100) surface and the energy gap becomes narrow when the adsorption occurs. It is found that the above-mentioned theoretical calculations agree well with the experiment results.

Zn_0.6Mn_0.2Ni_0.2Fe₂O₄ ferrite and their poly(o-toluidine) composites (ZMNF/POT) were prepared by a chemical precipitation method and an in situ polymerization method, respectively. Their composition, structure, morphology, conductivity and magnetic properties were characterized by means of modern testing technology. The results showed that the ZMNF particles were covered well by the POT, the conductivity of composites were mainly attributed to the POT content, while their magnetic properties were related to the ZMNF content. In the range of 1～15 MHz, the dielectric loss and conductivity of the POT and ZMNF/POT composites had better consistency with their conductivity; the magnetic loss of the composites was quite considerable and superior to that of the magnetic type ZMNF, and reached the maximum when the content of ZMNF is 31.74 wt% in the composites. The composites are hoped to used as advancing microwave absorption and shielding materials.

Graphene was coated on glassy carbon electrode (GCE) and cobalt hexacyanoferrate was then electrodeposited on the modified electrode to fabricate electrochemical sensor. Scanning electron microscope was used to characterize the nano-composite film. The electrochemical behaviors of hydroquinone (HQ), catechol (CT) and resorcinol (RS) on the modified electrode were investigated by cyclic voltammetry. The oxidation currents of CT, RS and HQ increased remarkably compared with those obtained at the bare GCE and graphene modified GCE. Differential pulse voltammetry was used for the simultaneous determination of CT, RS and HQ in their ternary mixture. The concentration of HQ, CT and RS showed good linear relationships with the oxidation peak current in the range of 1.0×10^－6～1.5×10^－4 mol/L, 1.0×10^－6～ 2.0×10^－4 mol/L and 3.5×10^－6～2.5×10^－4 mol/L, with correlation coefficients of R＝0.991, 0.993 and 0.992, respectively. The limits of detection for HQ, CT and RS were 2.0×10^－7, 2.1×10^－7 and 3.5×10^－7 mol/L (S/N＝3), respectively. The developed method was used to determination of water samples with recoveries of 95.6%～106.1%.

The synthetic methods of alkaline ionic liquid hydroxide 1-butyl-4-dimethy1 aminopyridine were optimized by using orthogonal experimental. By using triethylene diamine (DABCO) as catalyst and alkaline ionic liquid as solvent, aromatic aldehydes with methyl acrylate’s Baylis-Hillman reaction was studied. Experimental results showed that fast reaction rate and high yield were obtained in the presence of the alkaline ionic liquid. On this basis, Baylis-Hillman reaction under the influence of water-ionic liquid composite system was further studied, and obtained better result.

A novel resonance light scattering (RLS) method for the determination of palmatine hydrochloride (PaH) has been developed based on the largely enhanced RLS signals at 297 nm due to the interaction between Silicotungstic acid (STA) and PaH by electrostatic force in the pH 0.91 HCl-NaOAc medium. The linear range of PaH is 0.09～3.2 μg/mL. The limit of detection (LOD) is 9.1 ng/mL. In this work, the effects of pH and ionic strength on interaction were investigated. At the same time, the UV spectra, the fluorescence spectra and the reaction mechanism of system were also investigated. This method has been applied successfully for the determination of PaH in pharmaceutical and blood serum samples with RSD≤4.2%.

It is well known that the components of microcapsule prepolymers have great influence on the structures and morphologies of the resultant self-healing microcapsules. The synthesis of high-performance self-healing microcapsules is benefited to the presence of high-content multimethylol urea in the reaction system. In this contribution, the components of microcapsule prepolymers prepared under different reaction conditions, including temperatures, pH values and mole ratio of formaldehyde to urea, were studied and quantificationally analyzed using polarized microscopic melting point meter, infrared spectroscopy and 1H NMR spectroscopy. It was found that increasing the temperature and pH value in the reaction system could significantly promote the secondary reaction respectively, resulting in the decreased yield of dimethylol urea in the reaction system. When increasing the mole ratio of formaldehyde to urea, the yield of dimethylol urea in the reaction system increased, and the yield of trimethylol urea decreased simultaneously. Furthermore, the temperature of the reaction system during the heating process was monitored, and it indicated that the temperature changed at a constant path when a fixed heating rate was performed.

Nine new piperidinothienopyrimidinone derivatives were synthesized from the reaction of carbodiimide intermediate with primary, secondary amines and alcohols catalyzed by sodium alkoxide. The structures of the compound were confirmed by elemental analysis, ¹H NMR, MS and single crystal X-ray determination. The fungicidal activities of all the compounds were studied and some compounds exhibited good bacteriostasis activity. Among them, compound 7b exhibited fungicidal activity against Botrytis cinereapers, Rhizoctonia solani, and Gibberella zeae with inhibitive rates of 76.19%, 68.83% and 56.52%, respectively.

Cd(Ⅱ) modified Pt-electrode was prepared and the adsorption character of Cd(Ⅱ) on the electrode was studied by cyclic voltammetry. The mechanism of electrode response was discussed. A new method using oscillo-potentiometry for the titration of Cd(Ⅱ) was described by optimizing the testing conditions. In 0.1 mol/L hexamethylene tetramine solution (pH 6.0), Cd(Ⅱ) was titrated with EDTA, and two modified Pt-electrodes were used as bi-indicator electrode system. The end point of titration was determined by an abrupt maximum displacement of the fluorescence spot observed on the screen of the cathodic oscillograph. When Cd(Ⅱ) content was in the range of 9.0×10^－4～3.5×10^－3 mol/L, the recovery was in the range of 99.8%～100.3%. Furthermore, the modified electrode showed excellent stability and reproducibility. In 1.0×10^－3 mol/L Cd(Ⅱ) solution, the values of end point potentials obtained from 13 continuous determinations were all around 37 mV, and the relative standard deviation (RSD) was 0.02%. Moreover, the proposed method has been used in the determination of Cd(Ⅱ) contained in samples with recoveries of 99.71%～100.09% and RSD (n＝7) less than 0.81%, which are in accordance with the indicator method.

Design, synthesis and application of basic ionic liquids have attracted much extensive interest in recent years. The determination of the basic strength is of crucial significance for the utilization of basic ionic liquids. However, studies on the basicity characterization were rarely reported for basic ionic liquids to the best of our knowledge. In this paper, the acid-dissociation constant pK_b values of a series of basic ionic liquids synthesized were determined by potentiometric titration method. Then, the basicity of these ionic liquids was characterized by comparison of their pK_b values. Finally, the relationship between the basicity and structure of these ionic liquids was discussed. The results show that the basicity of carboxylate ionic liquids is determined mainly by their anions, whereas the different cation is able to have its basicity finely tuned. The results also show that the basicity of amino-functionalized imidazolium ionic liquid is weaker than that of triethylamine due to the strong electron withdrawing effect of the positively charged imidazolium ring.

Poly(lactic acid) (PLA) films consisting of α'-forms were prepared and uniaxially drawn. The effects of the drawing temperatures above the glass transition temperature on molecular weight and molecular weight distribution, chain conformation, degree of crystallinity and crystalline phase transformation were investigated by a combination of vibrational spectroscopy (infrared and Raman), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The general appearance of stress-strain behaviour of drawn PLA, and in particular its yield stress and Young’s modulus, is strongly affected by the drawing temperatures. The values decrease with increasing the stretching temperatures. The GPC results showed that the molecular weight decreases and its distribution becomes wider after drawing at various drawing temperatures. It was established that the α'-forms phase of PLA films does not transform into either an α or β crystals upon uniaxial drawing with various temperatures at a fixed draw ratio of 4. However, compared with undrawn α'-forms PLA films, the crystallinity and the degree of orientation of PLA products are greatly influenced by the drawing temperatures. The crystallinity is significantly increased upon deformation. The crystallinity and orientation of PLA products increase with increasing the draw temperature when the stretching temperature is <100 ℃, however, the degree of crystallinity and deformation will decrease when the temperature is ≥100 ℃. While the overall changes in physical properties can be attributed to changes in the degree of crystallinity as a function of drawing temperatures, polarized Raman spectra and XRD clearly illustrated changes and the differences in the amorphous and crystalline orientation as a function of processing conditions.

Three comb-like methyl methacrylate copolymer matrixes for gel polymer electrolyte (GPE) were synthesized by reacting methyl methacrylate-maleic anhydride copolymer (P(MMA-co-MAh)) with poly(ethylene glycol) monomethylether (PEGME) of different molecular weight (350, 600, and 750), respectively. Three kinds of GPE membranes made from comb-like copolymers as matrix, shorted for CL350, CL600, CL750, propylene carbonate (PC) as plasticizer and LiClO₄ as salt, have been prepared by solution casting technique. By studying the ion transporting properties of the GPE, it is found that the conduction mechanism of the GPE accords with VTF (Vogel-Tamman-Fulcher) equation, which is derived from free volume theory. Positron annihilation lifetime spectroscopy (PALS) was employed to analyze the properties of free volume in GPE systems and the effect of microstructure on conductivity of GPE membranes. It is noted that increasing the side chain length of polymer matrixes will increase the free volume existed in system. When the content of polymer matrix is 45 wt%, free volume in CL750 based GPE membrane is 21% larger than that in CL350 based GPE membrane. Correspondingly, compared with CL350 system, the ionic conductivity of CL750 system grows by 200%. It is apparent that the ionic conductivity of GPE membranes is affected by the structure of polymer matrix to a great extent.

Quantum dots (QDs), as a new class of biological nanoprobe, its fluorescence properties are related to the detection sensitivity. QDs with different core-shell structures vary in the resistance to the fluorescence quenching during surface modification. In this study, a series of core and core-shell QDs with different structure and composition were designed and synthesized. And they were modified with amphiphilic polymer. Their fluorescence properties during the surface modification were monitored by fluorescence spectroscopy. Experimental results show core QDs are the most easily quenched during the surface modification; the ability of resistance to quenching is enhanced after shell coating on core QDs, and this ability increases with the shell layers increase. Results also indicate the structure and composition of shells affect the resistance to fluorescence quenching. The resistance to fluorescence quenching is greatly enhanced when the core-shell QDs has a reasonable shell structure and composition. Furthermore, specific QD nanoprobes are constructed based on selecting appropriate structure of QDs and coupling with folic acid. The prepared QD nanoprobes are used for detection of breast cancer cells on flow cytometry. The results show that by optimizing the structure of core-shell QDs, the modified hydrophilic QDs have good fluorescence property. And the optimized hydrophilic QDs coupled with folic acid have targeting capability of cancer cells.