Polysaccharides are naturally occurring, nontoxic, safe, and abundant. However, the properties and functions of polysaccharides can be improved by mixing them with surfactants because of synergistic effects between them. The association of surfactants with polysaccharide chains can be regulated in aqueous systems through electrostatic, hydrophobic, dipolar, and hydrogen bonding interactions and steric hindrance effects, resulting in changes in the critical aggregation concentration (cac), critical micelle concentration (cmc), binding amount, surface adsorption, and interfacial rheology of aqueous systems. In this paper, recent progress of research on mixed systems of polysaccharides and surfactants, including measurement methods, are summarized. The physicochemical properties and interaction mechanisms of these mixed systems are explored.

Increased water solubility of molybdenum trioxide (MoO₃) induced by β-cyclodextrin (CD), with solubility dependent on β-CD concentration is reported. The dynamic equilibrium established between MoO₃ precipitation and dissolution shifted towards dissolution upon the addition of aqueous β-CD, to form a bluish-grey product. This was confirmed to be of β-CD and MoO₄^2- by: (1) X-ray photoelectron spectroscopy showed decreased Mo 3d_5/2 and 3d_3/2 binding energies of the product compared with those of MoO₃; (2) a strong band at 213 nm and new broad peak near 775 nm of the product were attributed to Mo＝O and Mo―O bond absorption; (3) a downfield shift of β-CD protons due to the effect of MoO₄^2- ions. An interaction between β-CD and MoO₄^2- has been revealed and hints at the possibility of exploiting it for improving MoO₃ physical properties

The dissolution and thermochemical properties of potassium styphnate [K₂(TNR)(H₂O)]_n and cesium styphnate [Cs₂(TNR)(H₂O)₂]_n in water and N,N-dimethylformamide (DMF) at 298.15 K were studied by calorimetry. The processes are endothermic in water, and exothermic in DMF because of the different molecular structure and polarity of the solutes and solvents. Empirical formulas for the solution enthalpies (Δ_solH), relative apparent molar solution enthalpies (ФL_i), relative partial molar enthalpies (L_i), and dilution enthalpies (Δ_dilH_1,2) are deduced by polynomial expressions, and standard solution enthalpies (Δ_solH_m^θ) are also calculated.

Spontaneous symmetry breaking of the N⁺H…O bond in chiral alanine crystals around 270 K was detected in situ by Raman vibrational scattering with b(cc)b geometry. An electron spin-flip transition of the N⁺H…O mode in D-/L-alanine was observed by the scattering of light with left/right orientation and its spin projection antiparallel to the direction of propagation. It is an internal magnetic field originated from the spin-orbit interaction. An obvious Raman wavenumber shift with opposite in sign and roughly one third of the asymmetry (A) of the scattered photon between D- and L-alanine crystals was observed. This shift was not seen in polycrystalline powder measurements because spin is an axial vector. An electron spin-flip transition of the methyne (C_α－H) mode around 260 K was shown to be approximative coincidence by examining the temperature-dependent relative intensity of asymmetric Raman scattering with c(aa)c geometry. This article provides evidence for the true chirality and parity-time (PT) asymmetry in molecular clusters of D- and L-alanine crystals.

The thermal stability and autocatalytic decomposition of 2,4-dinitrotoluene (2,4-DNT) is investigated under dynamic and isothermal conditions using differential scanning calorimetry (DSC). The temperature range of initial exothermic temperature (T₀) is 272.4-303.5℃, and its decomposition enthalpy (ΔH_d) is about 2.22 kJ·g^-1. An identification method based on a numerical simulation technique from the Swiss Institute for the Promotion of Safety and Security (Swiss method) is used to determine the characteristic parameters of the decomposition reaction, revealing that the decomposition of 2,4-DNT is potentially autocatalytic. The Malek method is used to determine the most probable mechanism function and kinetic parameters of 2,4-DNT decomposition. The Sestak-Berggren model with two parameters is suitable to describe the autocatalytic decomposition of 2,4-DNT, which is consistent with the results of the Swiss method and isothermal experimental results. Isothermal DSC experiments confirmed that the decomposition of 2,4-DNT is autocatalytic.

Intensity difference between odd- and even-numbered cluster ions is one of the characteristics of phosphorus clusters. Generally, for the clusters with cluster ion size n>25, intensities of odd-numbered cluster ions are much higher than those of their even-numbered neighbors. In order to better understand the size effect on the phenomenon, large phosphorus clusters (n~500) were generated by laser ablation on red phosphorus in vacuum. Their intensity distributions were also analyzed. Results show that the intensity difference between odd- and even-numbered cluster ions decreases with increasing cluster size for both cations and anions. Based on the observed trends for cations and anions, it can be estimated that the observed intensity alternation of even/odd numbered clusters may vanish for cluster ions with n>1000. These results exactly reflect the function of cluster as a bridge linking atoms in the gas phase and their bulk counterpart in the bulk phase.

A periodic interaction model with different intercalated anions (X=F^?, Cl^?, Br^?, I^?, NO₃^?, OH^?) is proposed for the CuZnMgAl quaternary hydrotalcites (CuZnMgAl-X). Based on density functional theory, the CuZnMgAl-X geometry was optimized using the CASTEP program. The distribution of anions in the interlayer, and the supra-molecular interaction between host layer and guest anions were investigated by analyzing binding energies, geometric parameters, Mulliken populations, hydrogen-bonding and densities of states. A decreased electronegativity of interlayer anion caused a transfer of charge from guest anions to host layer and a gradual decrease in the strength of electrostatic interaction and hydrogen bonding. The system band gap narrowed, electrons transferred to higher energy levels more easily, and the overall stability of the system decreased. The Cu dopant caused a deviation in CuZnMgAl-X valence band to high energies. Compared with traditional layered double hydroxides, the band gap narrowed and stability decreased, accounting for the difficulty in preparing copper-containing hydrotalcites.

Absolute weight values estimated from test data by ridge regression (RR) can reflect the significance of corresponding features. Based on RR and support vector machine (SVM), a new feature selection al rithm for high-dimensional data is proposed. Examples from bitter tasting thresholds (BTT) and cytotoxic T lymphocyte (CTL) epitopes are presented. All 531 physicochemical property parameters were employed to express each residue of one peptide, thus 1062 and 4779 descriptors were obtained for BTT and CTL, respectively. Each sample was divided into training and test sets, and weight estimates of all training set descriptors were generated by RR. According to the descending order of the weights, corresponding features were gradually selected until the mean square error (MSE) of leave-one-out cross validation (LOOCV) increased significantly. Based on smaller training datasets obtained from the previous step, the reserved features were available from multiple elimination rounds. 7 and 18 descriptors were selected by the new method for BTT and CTL, respectively. A quantitative structure-activity relationship (QSAR) model based on support vector regression (SVR) was established on extracted data with the reserved descriptors, and was then used for test data prediction. The fitting, LOOCV, and external prediction accuracies were significantly improved with respect to reported literature values. Because of the calculation speed, clear physicochemical meaning, and ease of interpretation, the new method is widely applicable to regression forecasting of high-dimensional data such as QSAR modeling of peptide or proteins.

Accurate prediction of molecular acidity with ab initio and density functional theory approaches is of great interest, but remains a challenging task. Density functional reactivity theory (DFRT) with quantum descriptors, such as molecular electrostatic potential and valence natural atomic orbital energies, has recently been developed and used for this purpose. Our previous study of substituted benzoic acids revealed a novel approach to quantitatively predict molecular acidity using the Hammett constant, which gave the same prediction accuracy as that of DFRT. In this work, we applied these two approaches to singly and doubly substituted phenol systems, a total of 83 molecules, confirming their effectiveness and robustness. High accuracy was obtained using both approaches, with the DFRT approach achieving slightly higher accuracy than the Hammett approach in general. These results shed further light on the molecular features verning physiochemical properties such as acidity and basicity, both locally on the atomic level and globally on the functional group or molecular level. Our present results confirm the validity of the sum rule of Hammett constants for doubly and multiply substituted compounds.

SO₄^2? doped polyaniline (PANI) counter electrodes (CEs) on fluorine-doped tin oxide (FTO) glass substrates were fabricated, using electrochemical method under constant bias for different polymerization time. The effect of polymerization time on surface morphology, structure (such as doping level, conjugation and oxidization state), and electrocatalytic activity for I^?/I₃^? redox reaction of the obtained PANI CEs was investigated by scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). SEM results indicated that the growth of PANI films on FTO substrate occurred in two phases. Properly increasing polymerization time could increase the specific surface area of PANI CEs, affording more electrocatalytic sites for the I^?/I₃^? redox reaction. Meanwhile, the conductivity of the PANI CEs increased gradually because of enhanced conjugation, emeraldine base (EB) structure, and SO₄^2? doping degree. If the polymerization time was too long, however, the CE conductivity would decrease due to the formation of a thick film and superabundance of oxidized structure, resulting in an increase in the electron transfer resistance and decrease in the electrocatalytic activity of PANI CEs for I^?/I₃^? redox reaction. Dye-sensitized solar cells (DSSCs) based on PANI CEs with a polymerization time of 300 s and D149 dye showed the best photovoltaic performance, with a solar-to-energy conversion efficiency of 5.30%. This result is approximately 88% of the efficiency of Pt CE based-solar cells, suggesting that PANI CEs polymerized with electrochemical method may replace Pt CEs in DSSCs.

A method of utilizing p-π conjugation effects for obtaining low-viscosity ionic liquids is presented. p-π conjugation effectively disperses anionic charge and reduces Coulombic interactions. Ionic liquids prepared in this study were 1-ethyl-3-methylimidazolium benzoate (EMIB) and 1-ethyl-3- methylimidazolium isonicotinate (EMIIN). They have carboxyl and aromatic ring p-π conjugated anions, and achieve low viscosities of 42 and 27 mPa·s, respectively. EMIB and EMIIN were employed as electrolytes, which were used to construct dye-sensitized solar cells (DSCs). After optimizing the composition, the ionic conductivity and triiodide ionic diffusion constant for the EMIB-based electrolyte were 1.43 mS·cm-1 and 1.45 × 10^-7 cm²·s^-1, respectively. For the EMIIN-based electrolyte, the ionic conductivity and triiodide ionic diffusion constant were 1.63 mS·cm^-1 and 2.01×10^-7 cm²·s^-1, respectively. These were higher than the corresponding values for the EMIB-based electrolyte because of EMIIN's lower viscosity. DSCs based on these two electrolytes attained satisfactory energy conversion efficiencies of 2.85% and 4.30% for EMIB and EMIIN, respectively, under an illumination intensity of 300 W·m^-2.

Cu₂S counter electrodes were prepared from the metal chalcogenide complex precursor using a novel method. A porous TiO₂ nanoparticle film and TiO₂ nanorod array photoanode were also fabricated. The corresponding CdS/CdSe-sensitized solar cells with the Cu₂S counter electrode were assembled and their photovoltaic performances were studied. The catalytic performance of the Cu₂S counter electrodes was investigated using electrochemical impedance spectroscopy. Compared with a platinum counter electrode, the Cu₂S one exhibited higher catalytic activity and better photovoltaic performance in quantum dot-sensitized solar cells.

Trollius chinensis pigment was extracted, and ultraviolet-visible (UV-Vis) absorption and Fourier transform infrared (FTIR) spectroscopy confirmed that anthocyanin compounds were the main components. Dye sensitized solar cells (DSCs) were sensitized from the natural pigments dissolved in different pH solutions. Open-circuit voltage increased with increasing pH,while short-circuit current density first increased and then decreased, attributed to an anthocyanin structural change with pH value. The highest observed power conversion efficiency was 0.292% at pH=5.

Three-dimensional (3D) hierarchical CNTs/ /S ternary composites were prepared by solution-based reaction-deposition, using graphene oxide ( ) and carbon nanotubes (CNTs) as precursors. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) indicated a uniform S coating on CNTs/ which arose because of the large specific surface area. CNTs interspersed between the layers to form a 3D porous structure. Constant current charge-discharge tests showed that CNTs/ /S composites had a high discharge capacity and excellent cycling stability, and delivered a high initial discharge capacity of 904 mAh·g^-1 at 1C rate. After 50 cycles at the same rate, the reversible capacity remained at 578 mAh·g^-1.

Electrochemical oxidation of 3-bromobenzoic acid (3-BBA) on a Pt electrode in alkali solution was studied by cyclic voltammetry and in situ Fourier transform infrared (FTIR) spectroscopy. The Pt electrode exhibited od performance for the electrooxidation of 3-BBA. At low oxidation potential (1000 mV), one electron was removed from the 3-BBA radical anion and the corresponding free radical was generated. A Bbromobenzene free radical cation and carbon dioxide were obtained after decarboxylation. The bromobenzene cation was then attacked by the hydroxyl radical, which was adsorbed on the anode, and the bromobenzene cation intermediate product was debrominated to form phenol. When the potential shifted to more positive values, phenol was electrooxided to produce dihydroxybenzene and benzoquinone. Maleic acid and fumaric acid were also detected as the reaction products of the ring-opening reaction.

The performance of proton exchange membrane fuel cell (PEMFC) was simulated with a microstructure lattice model of the catalyst layer, including the effect of liquid and gaseous water. Comparisons of simulations where liquid water was and was not factored in were carried out, demonstrating the necessity of including liquid and gaseous water effects in the catalyst microstructure. The distribution of the degree of liquid water saturation, oxygen concentration, and rate of oxygen reduction with catalyst layer thickness were calculated, and factors affecting these distributions were investigated. Water‘flooding’in the catalyst layer had a significant influence on PEMFC performance. Higher catalyst layer porosity facilitated water drainage and was beneficial to PEMFC performance.

The wetting behavior of poly(methyl methacrylate) (PMMA) surfaces by aqueous solutions of cationic surfactants, hexadecanol glycidyl ether ammonium chloride (C₁₆PC), hexadecanol polyoxyethylene (3) glycidyl ether ammonium chloride (C₁₆(EO)₃PC), and zwitterionic surfactants, hexadecanol glycidyl ether glycine betaine (C₁₆PB) and hexadecanol polyoxyethylene(3) glycidyl ether glycine betaine (C₁₆(EO)₃PB), were investigated by sessile drop analysis. The influence of surfactant type and concentration on contact angle was determined. The PMMA surface is modified hydrophobically only slightly at low bulk concentration because the surfactant molecules are parallel to the substrate surface and the hydrophilic groups are close to the surface. However, at high concentration, the surfactant molecules can adsorb onto the PMMA surface through Lifshitz-van der Waals interactions and hydrophilic groups directed towards the bulk phase of solution, which increases the hydrophilic character of the PMMA surface. The contact angles of cationic surfactants show little variation following the insertion of polyoxyethylene units. However, the presence of polyoxyethylene units in the zwitterionic surfactants leads to an obvious decrease of contact angle because of the formation of hemimicelles on the PMMA surface.

BiPO₄ nanorods were synthesized by reflux, and the effect of reaction time, reactant ratio and concentration, and pH value on BiPO₄ crystal structure and morphology was investigated. Nanorods were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area analysis (BET), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The ability of BiPO₄ to photo-degrade methylene blue (MB) was investigated. The reaction time and reactant concentration influenced the product morphology. The reactant ratio and pH value had a large effect on the product crystal structure and morphology, and also on the photo-activity of BiPO₄. Highly UV active BiPO₄ nanorods of monoclinic monazite/hexa nal mixed crystal structure suitable for photocatalysis could be prepared by carefully controlling the above conditions.

Carbon and nitrogen co-doped TiO₂ hollow spheres (CNTHs) were synthesized by hydrothermal treatment of titanium carbonitride (TiCN) in a mixture of H₂O₂, HF, ethanol, and water. CNTHs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible (UV-Vis) diffuse reflectance spectroscopy. Some of the carbon and nitrogen from TiCN was doped into the lattice of TiO₂ in situ, and some carbon atoms were incorporated into the interstitial positions of the TiO₂ lattice. The CNTHs exhibited enhanced absorption over the whole visible-light region and an obvious red shift at the absorption edges compared with that of TiO₂. The ability of the CNTHs to degrade methylene blue (MB) in aqueous solution under visible light irradiation (λ≥400 nm) was investigated. The CNTHs showed much higher photocatalytic activity than P25 in the degradation of MB because of the synergetic effects of their strong visible absorption and unique hollow sphere structure.

Magnetically graphitic mesoporous carbon (Fe/GMC) was synthesized, using SBA-15 as a template and sucrose as a carbon source, with the assistance of ferric nitrate impregnation. The properties of the products were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N₂ adsorption-desorption (BET), and Raman spectroscopy. The impregnation of Fe³⁺ promoted the partial graphitization of ordered mesoporous carbon at low temperature (900℃), and resulted in the production of magnetic Fe₃O₄ particles. These complex materials possessed an ordered mesoporous pore structure, large surface area, and magnetic properties. The adsorption properties of Fe/GMC for traditional Chinese medicine wastewater were studied in detail using UV-Vis spectroscopy. The results showed that the Fe/GMC materials displayed rapid adsorption, and had a high adsorption capacity. Fe/GMC could be used as an absorbent for the highly efficient removal of pigments from Carthamus tinctorius flowers via rapid solid-liquid magnetic separation.

Introducing surfactants including hexadecyltrimethylammonium bromide (CTAB), macro l 6000 (PEG6000), and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) triblock copolymer (P123) into the refluxing aqueous crystal nucleus slurry yielded morphology-tuned microcrystalline γ-MnO₂. γ-MnO₂ and the influence of surfactant modification were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), N₂ adsorption (BET), thermogravimetry analysis (TGA), O₂ temperature programmed desorption (O₂-TPD), and temperature programmed H₂ reduction (H₂-TPR). Surfactants led to differences in γ-MnO₂ morphology, surface area, oxygen desorption behavior and reducibility. The effect of reflux time on catalyst morphology is discussed. The catalytic performance of γ-MnO₂ during the solvent-free atmospheric oxidation of toluene was evaluated. PEG6000 modified γ-MnO₂ exhibited the highest catalytic activity judging by surface area because of a greater mixed valency and more anion vacancies. The greatest mass specific activity was obtained for P123 modified γ-MnO₂ with the largest surface area. Optimized reaction conditions yielded an 18.1% toluene conversion, and 87.4 and 73.2% total selectivity and selectivity for benzoic acid, respectively.

A series of Ba_1-xM_xFeO₃ (M=Mg, Ca, Sr; x=0, 0.1, 0.2) perovskites were prepared by the sol-gel method as NO_x storage reduction (NSR) catalysts. The effect of doping with alkaline earth metals (Mg, Ca, and Sr) on the NO_x storage and oxidation performance of the BaFeO₃ perovskites was investigated. Doping with Mg enhanced the NO_x storage capacity (NSC) of the BaFeO₃ perovskites in the temperature range 250-400 ℃, the Ba_0.8Mg_0.2FeO₃ perovskite exhibited the best NO_x storage performance, which reached its maximum at 350 ℃, with NSC>1200 μmol·g^-1 and the NO→NO₂ conversion of 53.4%. Compared with BaFeO₃, the monodentate nitrate appeared clearly for the Ba_0.8Mg_0.2FeO₃ sample after storing NO_x at 250 ℃. The amount of the monodentate nitrate on Ba_0.8Mg_0.2FeO₃ varied with the NO_x storage temperature in a similar manner to that of its NSC. Fourier transform infrared (FTIR) spectra indicated that doping with Mg induced an A-site deficient perovskite structure in BaFeO₃, which readily generates oxygen vacancies that act as the active sites for NO_x adsorption. Moreover, the residual M on the catalyst might also improve the NSC of the sample by forming the monodentate nitrate.

A poly(dimethylsiloxane) (PDMS) stamp was electrolessly plated using a cyanide-free solution. ld nanoparticles (AuNPs) were transferred from the PDMS stamp to indium tin oxide (ITO), (3- mercaptopropyl) trimethoxysilane modified ITO (MPTMS/ITO), and an ITO substrate electrodeposited with a thin copper film (Cu/ITO). AuNPs formed well-ordered structures which were characterized by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and Raman spectroscopy. Microcontact printing allowed thin AuNPs films to be directly transferred from PDMS to substrate, so is a simple, fast, cheap and environmentally-friendly technique. AuNPs patterned on the ITO substrate exhibited surface-enhanced Raman spectroscopy (SERS) activity which will be investigated in subsequent studies.

Ionic liquids 1-alkyl-3-methylbis(trifluoromethylsulfonyl)imide ([C_nmim][NTf₂]) are promising separating reagents in the nuclear fuel cycle. Their chemical structure changes slightly when exposed to γ radiation, but the apparent darkening of [C_nmim][NTf₂] occurs at low dose. This radiation-induced darkening of [C_nmim][NTf₂] should be investigated further. To understand the effect of radiation on [C_nmim][NTf₂], we systematically studied the influences of the length of the C(1)―alkyl chain and substitution of C(2)―H on the UV-Vis spectra of irradiated [C_nmim][NTf₂]. Fluorescence and mass spectra of [C_nmim][NTf₂] allowed the possible colored products to be determined. The darkening of [C_nmim][NTf₂] is more obvious as the length of the C(1)―alkyl chain and absorbed dose increase, but it is weakened effectively after methylation at the C(2)-position of the imidazole ring. The dominant colored products are possibly imidazolium cations containing double bonds, dimers of imidazolium cations and fluorinated imidazolium compounds. Imidazolium cations could aggregate through π-π stacking after γ-irradiation, and the associated states may also play a role in darkening these ionic liquids.

Diagnosis of emission spectroscopy on chemical vapor deposition (PCVD) of TiO₂ with atmospheric-pressure radio frequency (RF) plasma was studied. The dependences of relative intensity of atomic oxygen line, Ar excitation temperature, OH rotational and vibrational temperatures were investigated on partial pressures of O₂ and titanium tetraisopropoxide (TTIP) and input power, respectively. The relative intensity of the atomic oxygen line rapidly increased to a maximum and slowly decreased with increasing O₂ partial pressure. OH vibrational temperature gradually increased, whereas Ar excitation temperature and OH rotational temperature showed little change. The relative intensity of the atomic oxygen line decreased, Ar excitation temperature remained constant, and OH vibrational and rotational temperatures increased with increasing TTIP partial pressure. The relative intensity of atomic oxygen line decreased, whereas the Ar excitation temperature and OH vibrational and rotational temperatures increased with increasing input power.

Understanding the effect of temperature on the orientation, microstructure, integrity, and growth mechanism of ZnO films on the atomic scale is needed to clarify the process of film growth, control deposition conditions, and improve film quality. Using the reaction force field method of molecular dynamics, we theoretically studied the effect of substrate temperature (200, 500, and 800 K) on the quality of ZnO films. Some of our results agree with experimental observations. We found that the radial distribution function curves of the deposited structures were sharp and highly ordered. The thin film formed at 500 K possessed the most stable and ordered structure of those investigated. The film grew with an island mechanism, and two orientations were present on every deposited atomic plane, which led to the formation of a special fault structure at interfacial regions.

Ordered naphthalene-bridged hybrid periodic mesoporous organosilicas (PMOs) were synthesized by co-condensation of 2,7-bis(3-triethoxysilylpropylaminocarbonyloxy) naphthalene (NIS) and tetraethoxy orthosilane (TEOS) using cationic trimeric surfactant C₁₀H₂₁N⁺(CH₃)₂(CH₂)₂N⁺(CH₃)(C₁₀H₂₁)(CH₂)₂N⁺(CH₃)₂C₁₀H₂₁]·3Br^? as a structure-directing agent. The resulting samples were characterized by powder X-ray diffraction, high resolution transmission electron microscopy, nitrogen adsorption-desorption, and differential scanning calorimetry/thermogravimetric analysis. Ordered mesoporous hybrid materials with a crystal-like pore wall formed when the molar ratio of NIS to the sum of NIS and TEOS was 40%. When this value is below or above 40%, ordered mesoporous hybrid materials with amorphous phase in the pore walls, and nonporous hybrid materials are obtained, respectively. As the number of naphthyl groups in the pore walls increases, the thermal stability of the hybrid materials is enhanced through the strong π-π interactions between organic groups. Because of the fluorescent naphthyl groups in the silica framework, the PMOs exhibit optical behavior consistent with excimer formation. Absorption spectra of the PMOs show blue shifts compared with that of the precursor (NIS), suggesting the formation of aggregates in the pore walls of the hybrid materials. As the molar ratio of NIS to the sum of NIS and TEOS increases, the fluorescence quantum yield of the PMOs decreases through fluorescence quenching caused by aggregation of naphthyl groups.

Macroporous SiO₂ monoliths were prepared via a sol-gel process accompanied by phase separation using a tetramethoxysilane (TMOS) precursor, 0.01 mol·L^-1 HCl catalyst, propylene oxide (PO) gelation agent, and poly(ethylene oxide) (PEO, viscosity-averaged molecular weight (M_v): 10000) phase separation inducer. Monoliths were characterized by differential thermal analysis/thermogravimetry (DTA/ TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury porosimetry, and nitrogen adsorption/desorption analysis (BET). The mechanism of the epoxide-mediated sol-gel reaction and PEO induced phase separation was discussed. The addition of PEO induced phase separation, and monolithic SiO₂ with a cocontinuous macroporous skeletal structure was obtained at PEO/TMOS molar ratio of 0.0018. Monoliths had a narrow pore size distribution of 1-3 μm, surface area as high as 719 m²·g^-1 and pore volume of 0.48 m³·g^-1. This sol-gel transition is mediated by PO because of its strong nucleophilic properties and irreversible ring-opening reaction. Simultaneous phase separation is induced by PEO adsorbed on the SiO₂ oli mers.

Aqueous phase Cu doped ZnSe (ZnSe:Cu) quantum dots (QDs) stabilized with mercaptopropionic acid were prepared, and thiourea was used as a surface modifier to obtain core-shell ZnSe:Cu/ZnS QDs. QDs had a sphalerite structure, were uniformly dispersed, had an average particle size of approximately 5 nm and an emission peak at around 460 nm. After thiourea modification, a wide band-gap ZnS shell was coated on the QDs to passivate the surface, reduce surface states, and significantly improve fluorescence intensity. Thiourea modified ZnSe:Cu/ZnS QDs exhibit better surface passivation, fluorescence efficiency, and stability than those of other surface modifiers like Na₂S and thioacetamide. Quantum yields were further improved after UV irradiation eliminated surface dangling bonds.

Titania/graphite oxide (TiO₂/ ) nanocomposites were obtained from a facile in-situ method using titanium tetrachloride (TiCl₄) and . Nanocomposite structures and properties were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis absorption spectroscopy. TiO₂/ nanocomposites could be well dispersed in water, and the addition of waterborne polyurethane (WPU) yielded TiO₂/ -WPU coatings. During oxidation, the graphite structural layer bound with numerous functional groups, some of which were chemically bound TiO₂. The peak disappeared after combining with TiO₂ nanoparticles. UV absorption data indicated an increasing percentage of WPU with increasing content. There was an optimal additive concentration at which the best absorbance results were achieved. The thermal stability and UV and wear resistance of the WPU were greatly improved upon the addition of TiO₂/ .