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Halide perovskites are potential next‐generation optoelectronic devices. However, the film quality of this charming material fabricated by the conventional spin‐coating method is far from satisfactory, significantly affecting the optoelectronic devices' performance. Here, one facile slow‐evaporating solvent (SE) method is demonstrated to synthesize high‐quality organic–inorganic halide perovskite films. Compared with the conventional spin coating method, the films fabricated by this SE method show much higher crystallinity, oriented lattice, smoother surface morphology, and lower trap density. Besides, the photodetector manufactured by the SE method‐based film also performs much better than the ones by the spin‐coating method. Importantly, this universal method can be applied to different organic–inorganic halide perovskites, such as Dion–Jacobson (DJ) type and Ruddlesden–Popper type 2D halide perovskites and conventional 3D halide perovskites. This work gives an effective solution to improve the quality of the DJ‐type halide perovskites, which endows the halide perovskites with a more practical chance to be commercialized cosmically. [ABSTRACT FROM AUTHOR]

Conventional multi-material multi-layer flexible packaging offers excellent properties. However, it has recycling challenges, necessitating a shift to mono-material multi-layer flexible packaging for example all-polyethylene (PE) packaging which can be tailored through various synthesis and processing methods for different layers. In this work, we study how the key molecular properties (number-average molecular weight (Mn), weight-average molecular weight (M w ), molecular weight distribution (MWD), comonomer content (short chain branching)) and machine direction orientation (MDO) process draw ratio (MDX) influence the final morphology and mechanical properties of MDO-PE films which are intended as the outer layer of mono-material all-polyethylene multi-layer flexible packaging. Five PE grades and various blends were extruded and blown into films. Selected blown films were machine direction oriented to obtain the final MDO-PE films. Furthermore, one selected PE blown film was processed at different MDO process draw ratios while keeping other process parameters constant. From the molecular properties point of view, the higher molecular weight fractions provide a higher possibility for uniform stretching whereas lower molecular weight fractions provide a higher natural draw ratio and therefore higher modulus and stiffness enhancement. Further, the results show that increasing MDO process draw ratio leads to more fibrillation and increased crystallinity. Consequently, the tensile modulus and stiffness at the higher draw ratios increase as well and are comparable to conventionally used polymers in outer layers of multilayer flexible packaging. Thus, this work demonstrates that MDO-PE films with enhanced modulus can provide sufficient stiffness for the design of outer layer of mono-material multi-layer all-PE packaging which presents higher potential for mechanical recyclability. [ABSTRACT FROM AUTHOR]

A thin film of unsubstituted polythiophene (PT), an insoluble conjugated polymer, with molecular chains uniaxially oriented in plane was prepared by the friction transfer method. The structure of highly oriented thin films of PT was investigated using grazing-incidence X-ray diffraction (GIXD), ultraviolet–visible (UV–vis) spectroscopy, and infrared (IR) spectroscopy. The polarized UV–vis and IR spectra and GIXD measurements showed the PT molecular chains were well aligned in parallel to the friction direction. The GIXD studies clarified that the polymer backbones were aligned with very narrow distribution, such that the half-width was about 4 degrees. The degree of orientation of the PT friction-transferred film was higher compared with those of regioregular poly(3-alkylthiophene)s. Moreover, the GIXD results show a preferred orientation where the a-axis is perpendicular to the substrate plane.

Zinc oxide (ZnO) films were prepared on amorphous quartz substrates by sol-gel spin-coating using Zn(CH3COO)2•2H2O precursor. Isopropanol, ethanol and 2-methoxyethanol were used as solvents. The film drying temperature was kept constant at 200 ºC and the annealing temperature was varied from 400 to 800 ºC. Highly transparent and (002)-oriented hexagonal wurtzite-type ZnO films were obtained using isopropanol solvent. The ZnO films prepared at Tanneal = 600 ºC showed the highest (002) preferential orientation, however it was not the significant feature to achieve low resistivity. The uniform and (002)-oriented ZnO films prepared at Tanneal = 400 ºC display the highest transmittance (>93% in the visible region) and the lowest resistivity (7.1 Ω•cm).

Bismuth-based layer-structured Bi5Fe0.5Co0.5Ti3O15(BFCT) thin films have been deposited on Pt/Ti/SiO2/Si substrates by chemical solution deposition method. Using different heating rates during crystallization, we obtained randomly oriented and highlyc-axis-oriented BFCT films. Anisotropic ferroelectricity were determined with the remnant polarization (2Pr) ∼ 45.8μC/cm2for randomly oriented film and 2Pr∼ 25.3μC/cm2for highlyc-axis-oriented ones. Meanwhile, highlyc-axis-oriented BFCT film shows better fatigue endurance than that of random orientation. Both above can confirm the ferroelectric anisotropy. Furthermore, magnetic anisotropy also has been observed and possible reasons were discussed. [ABSTRACT FROM AUTHOR]

Abstract: Processing of the YMn2O5 powder is very challenging, since it decomposes to YMnO3 and Mn3O4 at temperatures close to 1180°C, while samples consolidation commonly demands high temperatures. The main goal of this work is to investigate a possibility to prepare thick films of YMn2O5, since their deposition generally requires significantly lower temperatures. Multiferroic YMn2O5 was synthesized by the hydrothermal method from Y(CH3COO)3·xH2O, Mn(CH3COO)2·4H2O and KMnO4 precursors. XRD, FE-SEM and TEM analysis showed that the obtained powder was monophasic, with orthorhombic crystal structure and columnar particle shape with mean diameter and length of around 20 and 50nm, respectively. The obtained powder was suspended in isopropyl alcohol with addition of appropriate binder and deflocculant. This suspension was used for electrophoretic deposition of YMn2O5 thick films under the high-voltage conditions and electric fields ranging from 250 to 2125V/cm. The films obtained at 1000V/cm and higher electric fields showed good adhesion, particle packing, homogeneity and very low porosity. It was shown that the deposition in extremely high electric fields (K C =2125V/cm) can influence the crystal orientation of the films, resulting in formation of preferentially oriented films. [Copyright &y& Elsevier]

The process of preparation of oriented BaFeO films with deposition of BaFeO nanoparticles from 1-butanol suspension in a magnetic field was studied. The structural, microstructural, and magnetic properties were investigated by X-ray diffraction, scanning electronic microscopy, and magnetic measurements and the annealing conditions influence on the films' orientations and microstructures was explored. The best BaFeO film properties, saturation magnetization of 49 emu g, high values of coercive field (4.4 kOe), and squareness ratio of 0.92, were obtained on well-crystallized oriented BaFeO films annealed at 1050 °C for 30 h. [ABSTRACT FROM AUTHOR]

Abstract: Oriented deposits of hard-magnetic barium ferrite were prepared using electrophoretic deposition (EPD). A stable suspension of highly anisotropic particles with diameters of a few 100nm and thicknesses of 10nm was prepared in 1-butanol. The electrophoretic velocities for the two orientations of particles with respect to the electrode were calculated. The particles migrated to the electrode with the basal plane perpendicular to the electrode. The oriented deposits were formed under the influence of the hydrodynamic force near the electrode. The sintering was accompanied by an anisotropic and abnormal grain growth and the oriented, larger grains affected most significantly the overall orientation of the films. The grain size was investigated by SEM image analysis and the orientation of the films was calculated from XRD patterns and determined from magnetic measurements. The films with the best orientations were prepared with the lowest applied voltage, where the electrophoretic velocity was the slowest. The films that were prepared with step EPD and sintered at 1150°C had a remanence-to-saturation magnetization of 0.9. The density of the film and the magnetization values were further increased by iso-static pressing of the deposits before sintering. [Copyright &y& Elsevier]

Abstract: Highly (100)-oriented BiFeO3–(Na0.5Bi0.5)TiO3 thin films without undesirable phases were synthesized by chemical solution deposition. The preparation of BiFeO3–(Na0.5Bi0.5)TiO3 sol and deposition procedure were studied. BiFeO3–(Na0.5Bi0.5)TiO3 thin films were deposited onto SiO2/Si substrates via a sol–gel method, with LaNiO3 as buffer layer. X-ray diffraction analyses show that the BiFeO3–(Na0.5Bi0.5)TiO3 films are highly (100)-oriented due to lattice match growth. Smooth surface with evenly distributed grains as small as about 50nm were observed by scanning electron microscope. The dielectric and insulating characteristics against applied field, and optical properties were studied. It is found that the introduction of Ti4+ reduces the number of oxygen vacancy greatly and thus can suppress the leaking current. The film has a conspicuous absorption in the blue and green light region, and band gap of about 2.74eV. [Copyright &y& Elsevier]

Abstract: Ce1− x Fe x O2−δ solid solution films were prepared on amorphous silica substrates by laser chemical vapor deposition using metal dipivaloylmethanate precursors and a semiconductor InGaAlAs (808nm in wavelength) laser. X-ray diffraction revealed the formation of single Ce1− x Fe x O2−δ phase at x ≤0.15, while CeO2 and Fe2O3 phases were found for higher Fe content. Highly (100)-oriented Ce1− x Fe x O2−δ (x =0.02) films were obtained at laser power, P L =50–200W and deposition temperature, T dep =800–1063K. Lotgering factor (200) was calculated to be above 0.8 for films prepared at P L =50–150W. X-ray photoelectron spectroscopy revealed the presence of Fe3+, Ce4+ and Ce3+ on solid solution films. Cross-sectional transmission electron microscope images disclosed a film columnar feather-like structure with a large number of nano-scale interspaces. Deposition rates were 2 or 3 orders of magnitude higher than those reported for conventional metal organic chemical vapor deposition of CeO2. [Copyright &y& Elsevier]

Highly oriented titanate nanotube (TNT) film was successfully synthesized by a simple electrophoretic deposition (EPD) method without any hard templates and surfactants. This oriented films adequately utilized the excellent properties of ID nanomaterials such as single crystal semiconductor architectures, large surface area, and superior charge transport, which lead to higher photocatalytic activity. We believe that this versatile method can be extent to fabricate other ordered ID nanomaterials films. [ABSTRACT FROM AUTHOR]

Abstract: The detailed structure of crystalline β-phase poly(9,9-dioctylfluorene) (PFO) films was studied by polarized optical measurements, transmission electron microscopy, and grazing-incidence X-ray diffraction. Crystalline β-phase PFO thin films were fabricated by a friction transfer technique and subsequent vapor treatment. Compared to the α-phase, the lattice parameters of the β-phase crystals shrank along the a-axis (film thickness direction) and elongated along the b-axis (side-chain direction), but the period along the c-axis (main-chain direction) remained nearly equal. These changes in molecular packing were consistent with a planar conformational change from the α-phase to the β-phase of PFO. [ABSTRACT FROM AUTHOR]

Abstract: CeO2 films were prepared on amorphous silica substrates by laser chemical vapor deposition using cerium dipivaloylmethanate precursor and a semiconductor InGaAlAs (808nm in wavelength) laser system. The laser spot size was about 20mm, which was sufficient to cover the whole substrate. Highly (100)-oriented CeO2 films were obtained at extraordinary high deposition rates ranging from 60 to 132μm/h. Films exhibited a columnar feather-like structure with a large number of nano-sized voids, and a surface morphology consisting of either nearly flat or pyramidal top-ending columns depending on the laser power. Nearly flat top-ending columns could be fairly (100)-oriented at the top and (111)-oriented laterally. [ABSTRACT FROM AUTHOR]

Abstract: ZnO films with preferred orientation along the (002) plane were successfully deposited by the sol–gel method using Zn(CH3COO)2·2H2O as starting material and inorganic precursor. A homogeneous and stable solution was prepared by dissolving the zinc acetate in a solution of ethanol and monoethanolamine. Thin films are obtained by spin-coating on glass substrates. ZnO films were obtained by preheating the spin-coated films at 300°C for 10min after each coating and postheating upto 550°C for 2h. The as-deposited films are transformed into mono-oriented ZnO upon thermal treatment. The films consist of spongy particles aggregates with an uniform size and homogenous surface. The films aim to be used in optoelectronic devices. Raman spectroscopy from ZnO films and deposit solutions has been investigated. New Raman results of the deposit solution suggest that Zn–O bond forms first in solution and that these entities play the role of germs initiating the crystallization mechanisms during films annealing. Raman spectra of the annealed films show the presence of a compressive stress within the film structure. [Copyright &y& Elsevier]

Abstract: Highly c-axis oriented zinc oxide, ZnO, thin film has been obtained at a very low pre-heating temperature, 120 °C. After depositing all layers, the film is annealed at 350 °C, for 5 h. The deposition process is designed to be compatible with silicon/silicon-dioxide substrates, to make piezoelectric coatings for integrated smart sensors. The films are synthesized by the sol–gel method and deposited onto a glass substrate. The deposition solution is prepared by dissolving zinc-acetate 2-hydrate in methanol. To optimize the film quality with respect to c-axis orientation, and surface uniformity, the selected parameters are: pre-heating temperature, spin-coating speed and number of coating layers. The effect of the deposition conditions is studied by applying experimental design and response surface techniques on the characteristic (002) peak, obtained by X-ray diffraction analysis. Surface uniformity and grain size are observed by scanning electron microscopy. [Copyright &y& Elsevier]

Detailed structures of friction-transferred poly(9,9-dioctylfluorene) (PFO) thin films have been studied using synchrotron-sourced grazing-incidence X-ray diffraction (GIXD). The results of in-plane GIXD were in full agreement with those of electron diffraction in our previous study. We also revealed the structures of liquid-crystalline (LC) and crystalline films that were prepared by rapid and slow cooling from the LC melted state of the friction-transferred films, respectively. For the crystalline films, the results of in-plane GIXD were not in full agreement with those of electron diffraction; additional weak peaks of the odd 001 reflections were observed only in the GIXD profiles. This implies that the twofold screw symmetry along the c-axis of PFO is broken. The rocking profiles for each reflection gave the order parameter of almost one for the crystalline films and 0.67 for the LC films. These results suggest the ability of friction transfer for obtaining single-crystal-like thin films and the importance of carefully designed annealing process for the applications of the films to various optoelectronic devices. [ABSTRACT FROM AUTHOR]

A series of PZT based ferroelectric thin films obtained by multitarget sputtering with different preferential orientations are studied by piezoresponse force microscopy (PFM). The modification of the substrate by the deposition of an extra TiO x layer, and the use of MgO-based substrates instead of the usual Si-based ones, change the preferential orientation of the films. The results of the analysis of the local piezoelectric properties allow us to discuss the origin of some special features observed, like the appearance of protruding grains in films with specific orientations, and the homogeneity of the piezoelectric performance at the nanoscale. [ABSTRACT FROM AUTHOR]

Biaxially oriented linear low density polyethylene (LLDPE) films are produced using the double-bubble process with different machine direction (MD) orientation levels and the same transverse direction (TD) blow-up ratio. Their mechanical behavior is characterized in terms of the tensile strength and tear resistance. The microstructure and orientation are characterized using microscopy, x-ray diffraction (XRD), and Fourier transform infra red spectroscopy (FTIR). The results indicate that MD tensile strength increases with increasing MD stretching (draw) ratio while the TD tensile decreases. Tear resistance remains mainly constant in TD and decreases in MD with increases in draw ratio. Morphology analysis reveals that overstretching lamellae tend to align perpendicular to MD with an increase of their lamellar dimensions. c-axis orientation of lamellae in MD increases with draw ratio while a- and b-axes orient towards normal direction (ND) and TD respectively. A good correlation is observed between c-axis orientation and MD tear resistance and tensile strength. [ABSTRACT FROM AUTHOR]

Mercuric iodide films were grown by the physical vapor deposition method on palladium-coated glass substrates 2''times2'' in size. The growth was performed in a system especially designed and constructed for getting a fine control of the growth parameters. The best growth conditions were a source temperature of 120degC, a growth temperature of 60degC and a growth time of 24 h, with an initial pressure of 6times10-3 Pa. Film thicknesses and grain sizes gave values ranging between 100 and 260 mum (10%), and between (10plusmn5) and (30plusmn10) mum, respectively. Films grew oriented with the (00l) crystalline planes parallel to the substrate, with a texture of 0.94, measured by X-ray powder diffraction. The dark current density of the films is lower than 0.3 pA/mm2 for electric fields below 0.4 V/mum, and their resistivity is 1.5times1014 Omega.cm. Mobility-lifetime values of 5.2times10-6 cm2/V and 6.2times10-6 cm2/V can be estimated for electrons and holes, respectively. Films give a sensitivity to X-rays of 37 nC/R.cm2. A signal to dark relation of 1120 was measured at 750 mR/s and 32 KVp, with an electric field of 0.4 V/mum applied to the film. The low dark current, as far as the high signal to noise results obtained, indicate these films as very suitable for direct and digital imaging [ABSTRACT FROM PUBLISHER]

During the last decade, a renewed interest has been devoted to ZnO-based materials owing to their applications in fields such as acoustic-wave and acousto-optic devices and short-wavelength semiconductor diode lasers. As opposed to traditional deposition by physical methods, the sol–gel process offers a simple, low-cost and highly-controlled way for ZnO film deposition. We have undertaken the systematic study of the key parameters that influence the texture and preferential orientation of films deposited by sol–gel procedures (precursor, solvent and additive nature and concentration, coating and heat treatment conditions). Zinc acetate dihydrate dissolved in ethanol is used as inorganic precursor; monoethanolamine acts at the same time as a base and a complexing agent. Thin films are obtained by dip- or spin-coating the solutions or colloidal sols (obtained by aging at 60–100 °C) on glass or quartz substrates. The as-deposited films are composed of amorphous zinc oxide-acetate species (a continuous gel, or sub-micronic particles), which are transformed into mono-oriented ZnO upon thermal treatment. Films arising from concentrated precursor solutions give rise to a (c//n) texture; films made up from dilute colloidal sols present an unusual (a//n) texture. We show that the preferential orientation of films depends on the nature of the solution or sol, precursor concentration and thermal conditions. We discuss the obtained orientations in terms of the interactions film–substrate and within the film. The UV absorption of these films is presented. [Copyright &y& Elsevier]

Thin microporous films with MFI type structure were deposited on silicon wafers via the seed method and spin coating of a stable colloidal mixture containing nanosized zeolites. The seed method includes adsorption of nanosized MFI seed crystals followed by hydrothermal synthesis of the seeds in order to obtain an intergrown film with a thickness of about 250 nm. In addition, thin MFI porous films with similar thicknesses were prepared by spin coating of stable colloidal suspensions and are compared with the seeded and grown layers. The diffractograms of the MFI films at grazing incidence and exit geometry were measured, which reflect the distribution of the crystal orientation along the film thickness. Preferred orientation of porous materials in the films is attributed to the deposition techniques and morphological features of the zeolite nanoparticles. The MFI adsorbed seeds and spin-deposited crystals are preferentially oriented with their a-axis perpendicular to the substrate, while the crystals in the grown film show an orientation change from the a- to the b-axis perpendicular to the substrate as a function of the film thickness. [Copyright &y& Elsevier]

A thin film of unsubstituted polythiophene (PT), an insoluble conjugated polymer, with molecular chains uniaxially oriented in plane was prepared by the friction transfer method. The structure of highly oriented thin films of PT was investigated using grazing-incidence X-ray diffraction (GIXD), ultraviolet–visible (UV–vis) spectroscopy, and infrared (IR) spectroscopy. The polarized UV–vis and IR spectra and GIXD measurements showed the PT molecular chains were well aligned in parallel to the friction direction. The GIXD studies clarified that the polymer backbones were aligned with very narrow distribution, such that the half-width was about 4 degrees. The degree of orientation of the PT friction-transferred film was higher compared with those of regioregular poly(3-alkylthiophene)s. Moreover, the GIXD results show a preferred orientation where the a-axis is perpendicular to the substrate plane. [ABSTRACT FROM AUTHOR]

Ethylene vinyl acetate (EVA) copolymers at various%VA content and AFFINITY** polyolefin plastomers (POP) were evaluated as blend components in various film applications rich in LDPE and LLDPE. The EVA resin miscibility with LDPE or LLDPE decreased as the VA content increased so that high VA EVA resins were partially or completely immiscible with LDPE or LLDPE resins. Both POP resins were miscible with LDPE or LLDPE resins. The blown films of LDPE/POP blends gave lower heat seal initiation temperature and lower haze compared to LDPE/EVA blended films. This is due to immiscibility of Elvax 3165 (18% VA) and Elvax 3128 (9% VA) with the LDPE resin. The impact and tear resistance of the POP based blown films were also superior. Oriented films of blends of POP with LLDPE and ULDPE resins exhibited significantly lower haze compared to blends of 12% VA EVA with LLDPE and ULDPE resins. Again, this is due to partial immiscibility of 12% VA EVA with LLDPE and ULDPE resins. The oriented films of blends of POP with LLDPE and ULDPE resins exhibited similar shrinkage at 90'C compared to blends of 12% VA EVA with LLDPE and ULDPE resins. [ABSTRACT FROM PUBLISHER]

This second part of a systematic study of the properties of crosslinked-oriented gelatin involves the effects of orientation and water content on the glass transition temperature Tgand on the melting behavior. The samples were the same as those in the preceding study, and their transition temperatures were determined by both differential scanning calorimetry and dynamic mechanical thermal analysis. The crosslinked gelatin which had been room-conditioned showed two transition temperatures: the lower one was attributed to Tg of the water-plasticized gelatin, and the higher one was interpreted as Tg of dried gelatin superimposed by melting. A rather unusual situation arose because of the fact that the Tg and melting temperatures Tm (217 and 230°C, respectively) are so similar. Using water as plasticizer not only decreases Tg but produces imperfect crystallites which melt below the Tg of the system. The presence of the amorphous phase in the glassy state would presumably make it essentially impossible to define a melting point or crystallization temperature in the normal manner, as an equilibrium between crystalline and amorphous phases. [ABSTRACT FROM AUTHOR]

This study is an extension of previous work on cellulosics [(1994) Colloid Polym Sci 272: 284, 393] that showed that unusually good mechanical properties can be obtained by drying a swollen network of semirigid chains in a state of strain. This novel approach is applied in this investigation to gelatin, because of its attractive environmental characteristics but poor mechanical properties in the unmodified form. Since drawing of non-crosslinked gelatin is not practical, crosslinking by formaldehyde was used, followed by swelling, drawing and drying at fixed length. Mechanical tests were performed in static and dynamic modes. In this way improvements of Young's modulus E, and stress at break σ were determined as a function of gelatin concentration during drying. An increase in E and σ up to 2-3 times, and in the dynamic modulus E′ up to 6 times, was obtained when the draw ratio λ reached 4-5, after which E, E′, and σ were found to decrease. Such behavior is explained by the highest orientation being achieved at λ=4-5, as proved by x-ray analysis. At λ=10-20 the orientation is lost due to relaxation of chain segments, which is preceded by partial destroying of the network structure (chemical and physical), possibly via chain scission, but probably mostly by the pulling out of chains from crystallites. In any case, the mechanical properties become poor again. The improvements reported above were referred to the undrawn but crosslinked gelatin. Compared to the starting isotropic non-crosslinked material, the improvement is slightly higher. The observation that the improvements are less than those obtained for the cellulosics is explained by the coexistence of interpenetrating chemical and physical networks, which is typical of gelatin. This structural feature drastically reduces the orientability of the chains and the improvements that can be expected in the mechanical properties. [ABSTRACT FROM AUTHOR]

The networks of cellulose acetate and hydroxypropylcellulose prepared in the first part of this investigation were studied with regard to their mechanical properties. The quantities of particular interest were increases in tensile modulus and tensile strength obtained by drying the swollen films under strain, both uniaxial and equi-biaxial. These increases or improvements in mechanical properties were determined as a function of polymer concentration during cross-linking, polymer molecular weight, degree of cross-linking, and elongation during drying. In all cases, the improvements increased with increase in elongation during drying, and the largest increases were obtained in the case of the highest molecular weight polymer which had been lightly cross-linked in dilute (isotropic) solutions. The extent of ordering in these systems was gauged approximately by measurements of birefringence, which were correlated with their tensile moduli and tensile strengths. [ABSTRACT FROM AUTHOR]

The effect of different-sized polyhydric alcohols on the absorption and circular dichroic spectra of the purple membrane has been studied over the wavelength region 800 to 185 nm. Analysis of both the solution and the film spectra of the membrane revealed that these solvents induce conformational changes in the sole membrane protein, bacteriorhodopsin. Additional evidence supportive of these changes was obtained from protein fluorescence spectral studies. Although the net secondary structure of the bacteriorhodopsin is not observably altered, there is a reversible change in the protein tertiary structure. This change does not result in any significant change in the membrane crystallinity or the alignment of the protein helical polypeptide segments with respect to the membrane plane. However, it is of sufficient extent to change the protein-induced screw sense of the retinyl-chromophore symmetry and the local environments of the protein aromatic residues. The underlying mechanism appears to be a membrane surface-solvent interaction phenomenon since the spectral perturbation caused by these solvents appears to be independent of their effective sizes. Furthermore, partial enzymatic removal of the hydrophilic portion of the bacteriorhodopsins with papain increased the response of the membrane to this perturbation. An interpretation of these results is that polyhydric alcohols enhance hydrophobic interactions in the purple membrane which induces a more compact conformation of the bacteriorhodopsin. A possible molecular mechanism is presented. [ABSTRACT FROM AUTHOR]

Abstract: (100)-Orientation preferred BiFeO3–(Na0.5Bi0.5)TiO3 thin films with single perovskite phase and good crystallinity were successfully deposited on glass substrates by chemical solution deposition. X-ray diffraction analyses showed that the addition of (Na0.5Bi0.5)TiO3 to BiFeO3 can suppress the formation of secondary phases, promote the (100)-orientation growth, and improve the crystallinity of the films. Dense microstructure with evenly distributed grains about 100nm was observed by scanning electron microscope. The optical measurements showed that the films have a conspicuous absorption in the blue and green light region and band gaps around 2.8eV. These results demonstrated that BiFeO3–(Na0.5Bi0.5)TiO3 thin films deposited on glass substrates are promising candidates for optoelectronic or photovoltaic materials. [Copyright &y& Elsevier]

Layered rare earth hydroxides (LRHs) have emerged as novel optical materials for various applications, but an effective method for orientation controlled growth of LRH films is not yet well established. Exfoliated nanosheets of LRHs are generally employed as building blocks for the construction of highly oriented films. In these cases, assembled LRH nanosheets tend to orient themselves parallel to the substrate surface. In the present work, direct growth of LRH sheets in a direction preferably perpendicular to flat glass and quartz tube substrates is successfully accomplished by adopting the chemical bath deposition technique. In particular, Tb3+‐doped layered yttrium hydroxide (LYH:Tb) films are grown under several different conditions to evaluate their effects on film growth. Both slide glass and a quartz tube coated with LYH:Tb film are further used as a replaceable adsorbent kit to detect and remove Cr(VI) ions utilizing the typical luminescence quenching of Tb3+ by the filter effect of adsorbed Cr(VI). Owing to high surface roughness caused by the microscale hierarchical architecture, the wettability of the LYH:Tb film can be also easily changed from superhydrophilic to superhydrophobic by a simple stearic acid treatment. [ABSTRACT FROM AUTHOR]

(Y0(.975− x)) Gd(x)Dy(0.025)(2)(OH)(5)NO(3) · nH2O (0 ≤ x ≤ 0.975) LRH crystals with tens of micron sized laterals have been hydrothermally synthesized by adding mineralizer NH(4)NO(3). Smaller LRHs particles, expanded main layer, and shorter interlayer distance were found at a higher Gd incorporation. Free anions NO− 3 at the interlayer of LRHs have been completely replaced by oleate anions with the help of hydrothermal processing, thus weakening the interaction of layers. Therefore, tens of micron sized LRH nanosheets can be easily exfoliated from the oleate-intercalated LRHs in toluene. Highly [111] oriented and transparent films of (Y0975− x Gd x Dy0.025)2O3 (0 ≤ x ≤ 0.975), with thicknesses of ~12 nm, have been constructed through spin-coating the colloidal suspension of exfoliated nanosheets on quartzs, followed by calcination at 800 °C. Under excitation at 270 nm, the oxide films exhibit typical yellow emission at 576 nm, whose intensity shows a clear dependence on Gd3+ concentration. Increasing the Gd content from 0 to 97.5 at.% yielded a 450% increase in the yellow emission intensity, owing to the energy transfer from Gd(3+) to Dy(3+). Because Gd(3+) content has little influence on fluorescence lifetime, fluorescence decay analysis yields similar lifetimes of ~1.45 ± 0.30 ms for all the samples.