5,10,15,20-四(对氯苯基)卟啉羟基稀土配合物的光谱研究

研究了四(对氯苯基)卟啉及其羟基稀土配合物的紫外-可见光谱、红外光谱和拉曼光谱,对主要谱带进行了经验归属,讨论了中心离子对紫外光谱和共振拉曼光谱结构敏感带频率的影响.     

Evolution of a polysulfone nanofiltration membrane following ion beam irradiation

Ion beam irradiation was used to modify the surface of a sulfonated polysulfone water treatment membrane. A beam of 25 keV H (+) ions with four irradiation fluences (1 x 10 (13), 5 x 10 (13), 1 x 10 (14), and 5 x 10 (14) ions/cm (2)) was used to study the effects of ion beam irradiation on chemical structure, surface morphology, microstructure, and performance. XPS and ATR-FTIR analyses were performed on the virgin and irradiated membranes in order to determine the changes to chemical structure incurred by ion beam irradiation. The results showed that some sulfonic and C-H bonds were broken and new C-S bonds were formed after irradiation. AFM analysis showed that the roughness of the membranes decreased after irradiation, and the decrease in surface roughness was proportional to the increase in irradiation fluence. An increase in flux after ion beam irradiation was also observed along with a smaller flux decline during operation. Flux was not a function of irradiation fluence. Hydrophobicity, pore size distribution, and membrane rejection efficiencies were not affected by ion beam irradiation. Overall, irradiation led to an improvement in membrane performance.     

Carbon ion beam induced modifications of optical,structural and chemical properties in PADC and PET polymers

We report a study on the carbon ion beam induced modifications on optical, structural and chemical properties of polyallyl diglycol carbonate (PADC) commercially named as CR-39 and Polyethyleneterepthalate (PET) polymer films. These films were then irradiated by 55 MeV C⁵⁺ ion beam at various fluences ranging from 1×10¹¹ to 1×10¹³ ions/cm². The pristine as well as irradiated samples were subjected to UV–Visible spectral study (UV–Vis), Photoluminescence (PL), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It has been found that ion irradiation may induce a sort of defects in the polymers due to chain scission and cross linking as observed from PL spectral study. It is revealed from UV–Vis spectra absorption edge shifted towards longer wavelength region after irradiation with increasing ion fluence. This shift clearly reflects decrease in optical band gap. The XRD study indicates the gradual decrease in intensity in case of PADC with increasing ion fluence. However, the intensity pattern increased in case of PET at fluence of 10¹¹ ion/cm² then decreased with further increase in fluence. Crystalline size of PADC was found to be decreasing gradually with increase of ion fluence. Whereas, the crystalline size of PET films found to increase with lower fluence and decreases with higher ion fluence. FTIR spectrum also shows the change in intensity of the typical bands after irradiation in the both the polymers. The results so obtained can be used successfully in heavy ions dosimetry using well reported techniques.     

Orthogonal time-of-flight secondary ion mass spectrometric analysis of peptides using large gold clusters as primary ions

Secondary ion mass spectrometry (SIMS) for biomolecular analysis is greatly enhanced by the instrumental combination of orthogonal extraction time-of-flight mass spectrometry with massive gold cluster primary ion bombardment. Precursor peptide molecular ion yield enhancements of 1000, and signal-to-noise improvements of up to 20, were measured by comparing SIMS spectra obtained using Au(+) and massive Au(400) (4+) cluster primary ion bombardment of neat films of the neuropeptide fragment dynorphin 1-7. Remarkably low damage cross-sections were also measured from dynorphin 1-7 and gramicidin S during prolonged bombardment with 40 keV Au(400) (4+). For gramicidin S, the molecular ion yield increases slightly as a function of Au(400) (4+) beam fluence up to at least 2 x 10(13) Au(400) (4+)/cm(2). This is in marked contrast to the rapid decrease observed when bombarding with ions such as Au(5) (+) and Au(9) (+). When gramicidin S is impinged with Au(5) (+), the molecular ion yield decreases by a factor of 10 after a fluence of only 8 x 10(12) ions/cm(2). Comparison of these damage cross-sections implies that minimal surface damage occurs during prolonged Au(400) (4+) bombardment. Several practical analytical implications are drawn from these observations.     

The influence of Au-nanoparticles presence in PDMS on microstructures creation by ion beam lithography

3D microstructures in pure poly(dimethylsiloxane) (PDMS) and PDMS with embedded Au nanoparticles were prepared by ion beam lithography without any further etching. Two mega-electron volts helium and 10 MeV oxygen ions were used for ion microstructuring. Parallel lines of 1 mm in length and 10 μm in thickness were fabricated for investigation of the effect of the nanoparticles presence in the polymer on the surface morphology of the created microstructures. The created microstructures were checked by optical microscope. Infrared (IR) spectrometry was used to study the effect of the ions type and fluence on the chemical changes of the material. Atomic force microscopy was used for the fine detail study as well as for checking the microstructure quality. Analysis revealed an increased radiation resistance of the nanocomposite compared to the pure PDMS. Shrinkage is proportional to the fluence, but the maximum value for both materials is limited by saturation. 3D microstructure in modified PDMS obtained at the same irradiation condition as pure PDMS is characterized by its smaller height. Obtaining the microstructure in nanocomposite of the same height as in pure PDMS by increasing the fluence can be impossible due to saturation of shrinkage and/or radiation-induced heating of the material.     

Raman study of the coordination structure of a rare Earth-acetate complex in water

The Raman spectra of aqueous LnCl(3) x 20H(2)O x CH3(C)OOLi (LnCl(3), rare earth chloride) solutions have been measured in the liquid state. The change of the Raman symmetric Ln(3+)-OH(2) stretching band (v(w)) showed that the decrease in the ionic radius of rare earth (Ln(3+)) ions induces a change in coordination number of the Ln(3+) ion. The two peaks at 946 and 958 cm(-1) of the C-C stretching band (v(CC)) of the acetate ion are assigned to the bidentate ligand and the polymeric chain structure, respectively. The coordination structure of the acetate ion to Ln(3+) ion prefers the bidentate ligand to the polymeric chain structure throughout the rare earth series. The fraction of the bidentate ligand increases with decreasing ionic radius of the Ln(3+) ion. On the basis of the analyses of the v(w) and v(CC) bands, the change in the coordination number of the Ln(3+) ion is mainly due to the structural change (from the polymeric chain structure to the bidentate ligand) of the Ln(3+)-acetate complex rather than a elimination of one water molecule. Our results show that the Ln(3+) ions tend to form the bidentate ligand rather than the divalent (M(2+)) ions.     

Optical Properties of Swift Heavy Ion Beam Irradiated Polycarbonate/Polystyrene Composites Films

Polycarbonate/polystyrene composites films were irradiated by 55 MeV Carbon ion beam with fluence ranging from 1 × 10¹¹ to 1 × 10¹³ ions/cm². The polymer composites films were prepared by solution mixing method. The effects of ion beam on structural, optical and surface morphology of PC/PS composites films were investigated by X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis), Fourier Transform Infrared Spectroscopy (FT-IR) and Optical Microscope. The XRD pattern shows the average crystallite size, percentage of crystallinity and inter-chain separation, which decreases with increase in ion fluences. UV-vis spectra show that the energy band gap and transmittance decreases while number of carbon atoms increases with fluences. The FT-IR spectra evidenced very small change in cross linking and chain scissoring at high ion fluences, while the optical microscopy shows a color change with ion fluence.     

Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×10¹³ to 5×10¹⁴ cm^?2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet–visible (UV–vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed.     

Physio-chemical influence of high electron-phonon coupling induced by 120 MeV Ag9+ SHI irradiation on exfoliated MoS2 - PVA nanocomposite films for achieving remarkable electrical conductivity for potential application in organic electronics

Swift heavy ion (SHI) irradiation technology is known to enhance the optical, electronic, mechanical, and electrical properties in polymer nanocomposites by the virtue of electron-phonon coupling. In the present work, Molybdenum disulphide (MoS₂), a two-dimensional metal dichalcogenide, has been exfoliated via liquid-phase exfoliation using N-methyl-2- pyrrolidone (NMP) as the solvent that yielded nanosheets of around 2–4 layers as depicted by HR-TEM images. MoS₂ - PVA free-standing films were prepared by wet chemical technique i.e. solution casting method and irradiated by focussed high-energy Ag⁹⁺ ion beam at fluence range of 1E10 - 3E11 ions/cm². As a consequence, the structural modification was observed by X-Ray diffraction studies that showed the shift of (002) plane of MoS₂ while Raman studies indicated the decrease of degree of disorderness at fluence 1E10 ions/cm². SHI irradiation has found to induce a two-order increase in the electrical conductivity yielding a 9.7 E-3 S/cm against that of the pristine films at 2.6E-5 S/cm. The enhanced conductivity is attributed to the induced dispersion and annealing of MoS₂ nanosheets in the PVA matrix due to the interaction of 120 MeV Ag⁹⁺ ion beam irradiation as explained by Thermal spike model.     

High-energy ion implantation of polymers: Poly(ethylene terephthalate)

The effect of high-energy ion implantation of oxygen into a thin film of poly(ethylene terephthalate) (PET) was studied by Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC). Mylar samples 13 μm thick were implanted with 6-MeV oxygen ions at fluences ranging from 5 × 10¹² to 2 × 10¹⁴ ions/cm². The DSC data showed a substantial loss of crystallinity, even at the lowest fluence, which extended deeper into the polymer film than the predicted range for oxygen deceleration in PET. Solubility measurements indicated the presence of cross-linking, especially at the highest fluence, but bands due to cross-linking could not be detected in the infrared. The trans/gauche ratio for the glycol group conformation was measured by a pair of conformationally sensitive infrared bands. Surprisingly, the conformation of the glycol segments did not change appreciably with increasing fluence, although crystallinity decreased and degree of cross-linking increased. The implications these results have on possible mechanisms of chemical and physical alterations of the polymer structure by ion implantation are discussed.     

Carbon ion irradiation induced surface modification of polypropylene

Polypropylene was irradiated with ¹²C ions of 3.6 and 5.4 MeV energies in the fluence range of 5×10¹³–5×10¹⁴ ions/cm² using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1–6 μm) were observed, but at higher fluence (1×10¹⁴ ions/cm²) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed.     

1,4—双（苯基乙炔基）苯及其双取代苯基衍生物的研究

合成了1,4-双(苯基乙炔基)苯及其双取代苯基衍生物。测定了它们的荧光量子产率、激光转换效率、红外光谱、拉曼光谱,指派了主要官能团的特征频率,讨论了化合物结构和取代基效应。     

Competing ion decomposition channels in matrix-assisted laser desorption ionization

We gauged the internal energy transfer for two dissociative ion decomposition channels in matrix-assisted laser desorption ionization (MALDI) using the benzyltriphenylphosphonium (BTP) thermometer ion [PhCH 2PPh 3] (+). Common MALDI matrixes [alpha-cyano-4-hydroxycinnamic acid (CHCA), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SA), and 2,5-dihydroxycinnamic acid (DHB)] were studied with nitrogen laser (4 ns pulse length) and mode-locked 3 x omega Nd:YAG laser (22 ps pulse length) excitation. Despite the higher fluence required to initiate fragmentation, BTP ions indicated lower internal energy transfer with the picosecond laser in all three matrixes. These differences can be rationalized in terms of phase explosion induced by the nanosecond laser vs a stress-confinement-driven desorption mechanism for the picosecond laser. For the two ion production channels of the BTP thermometer ion, breaking a single bond can result in the formation of benzyl/tropylium ions, F1, or triphenylphosphine ions, F2. In SA and DHB, as well as in CHCA at low fluence levels, the efficiency of these channels (expressed by the branching ratio I F1/ I F2) is moderately in favor of producing tropylium ions, 1 < I F1/ I F2 < 6. As the laser fluence is increased, for CHCA, there is a dramatic shift in favor of the tropylium ion production, with I F1/ I F2 approximately 30 for the nanosecond and the picosecond laser, respectively. This change is correlated with the sudden increase in the BTP internal energies in CHCA in the same laser fluence range. The large changes observed in internal energy deposition for CHCA with laser fluence can account for its ability to induce fragmentation in peptides more readily than SA and DHB.     

Molecular assembly in synthesised hydrotalcites of formula Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O--a vibrational spectroscopic study

Infrared and Raman spectroscopy have been used to characterise synthetic hydrotalcites of formula Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O. The spectra have been used to assess the molecular assembly of the cations in the hydrotalcite structure. The spectra may be conveniently subdivided into spectral features based (a) upon the carbonate anion (b) the hydroxyl units (c) water units. The Raman spectra of the hydroxyl-stretching region enable bands to be assigned to the CuOH, ZnOH and AlOH units. It is proposed that in the hydrotalcites with minimal cationic replacement that the cations are arranged in a regular array. For the Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O hydrotalcites, spectroscopic evidence suggests that 'islands' of cations are formed in the structure. In a similar fashion, the bands assigned to the interlayer water suggest that the water molecules are also in a regular well-structured arrangement. Bands are assigned to the hydroxyl stretching vibrations of water. Three types of water are identified (a) water hydrogen bonded to the interlayer carbonate ion (b) water hydrogen bonded to the hydrotalcite hydroxyl surface and (c) interlamellar water. It is proposed that the water is highly structured in the hydrotalcite as it is hydrogen bonded to both the carbonate anion and the hydroxyl surface.     

Investigation of 500 keV Si ion induced surface structuring of Ni and Ti for enhancement of field emission properties

The present paper reports the investigation of surface morphology, elemental composition, phase changes and field emission properties of Si ion irradiated nickel (Ni) and titanium (Ti). The Ni and Ti targets have been irradiated with 500 keV Si ions generated by Pelletron accelerator at various fluences ranging from 6.9 × 10¹³ to 77.1 × 10¹³ ions/cm². Stopping range of ions in matter analysis revealed higher values of electronic stopping and sputtering yield for Ni as compared with Ti. For both irradiated metals, electronic energy loss dominant over the nuclear stopping. The growth of induced surface structures have been analysed by using field emission scanning electron microscopy (FESEM) analysis. In case of Ni, as the ion fluence increases from 6.9 × 10¹³ to 65.8 × 10¹³ ions/cm², the formation of spherical particulates, agglomers and sputtering is observed. Although in the case of Ti, with the increase of Si ion fluence from 11.6 × 10¹³ to 77.1 × 10¹³ ions/cm², the formation of irregular-shaped particulates along with crater and sputtered channels is observed. X-ray diffraction (XRD) analysis shows that no new phase is identified. However, a significant increase in peak intensity is observed with increasing ion fluence. The variation in crystallite size and dislocation line density is also observed as a function of Si ion fluence. Fourier transform infrared spectroscopy analysis shows that no bands are formed after the Si ion irradiation. Field emission properties of ion-structured Ni and Ti are well correlated with the growth of surface structures observed by SEM and dislocation line density evaluated by XRD analysis.     

Water exchange rates in the diruthenium mu-oxo ion cis,cis-[(bpy)(2)Ru(OH(2))](2)O(4+).

Addition of 2 equiv of Ce(4+) to the dimeric ruthenium mu-oxo ion cis,cis-[(bpy)(2)Ru(OH(2))](2)O(4+) (formal oxidation state III-III, subsequently denoted [3,3]) or addition of 1 equiv of Ce(4+) to the corresponding [3,4] ion gave near-quantitative conversion to the [4,4] ion, confirming our recent assignment of this oxidation state as an accumulating intermediate during water oxidation by the cis,cis-[(bpy)(2)Ru(O)](2)O(4+) ([5,5]) ion. The rates of water exchange at the cis-aqua positions in the [3,3] and [3,4] ions were investigated by incubating H(2)(18)O-enriched samples in normal water for predetermined times, then oxidizing them to the [5,5] state and measuring by resonance Raman (RR) spectroscopy changes in the magnitudes of the O-isotope sensitive bands at 780 and 818 cm(-1). These bands have been assigned to Ru=(18)O and Ru=(16)O stretching modes, respectively, for ruthenyl bonds formed by deprotonation of the aqua ligands upon oxidation to the [5,5] state. An intermediate accumulated during the course of the isotope exchange reaction that gave a [5,5] ion possessing both approximately 782 and approximately 812 cm(-1) bands; this spectrum was assigned to the mixed-isotope species, (bpy)(2)Ru((16)O)(16)ORu((18)O)(bpy)(2)(4+). Kinetic analysis of solutions at various levels of oxidation indicated that only the [3,3] ion underwent substitution; the exchange rate constant obtained in 0.5 M trifluoromethanesulfonic acid, 23 degrees C, was 7 x 10(-3) s(-1), which is (10(3)-10(5))-fold larger than rate constants measured for anation of monomeric (bpy)(2)Ru(III)X(H(2)O)(3+) ions bearing simple sigma-donor ligands (X).     

Raman studies on the interaction of the reactants with the platinum nanoparticle surface during the nanocatalyzed electron transfer reaction

Raman studies are conducted to understand the specific interactions between the individual reactants and the platinum nanoparticle surface during the nanocatalyzed electron transfer reaction between hexacyanoferrate (III) ions and thiosulfate ions. When Pt nanoparticles are added to the thiosulfate ion solution, a shift in the symmetric SS stretching mode is observed compared to the frequency observed for the free thiosulfate ions in solution, suggesting that binding to the Pt nanoparticle surface occurs via the S- ion. It is also observed that there are no shifts in the symmetric and asymmetric OSO bending or SO stretching frequencies. This suggests that the thiosulfate ions do not bind to the nanoparticle surface via the O- ion. When platinum nanoparticles are added to the hexacyanoferrate(III) ion solution, evidence is found for both adsorbed hexacyanoferrate(III) ions and a platinum cyanide complex. For adsorbed hexacyanoferrate(III) ions, the CN stretching frequency is observed at 2101 cm(-1) and the Fe-C stretching frequency is found at 368 cm(-1). The observed CN stretching frequencies located at 2147 and 2167 cm(-1) provide strong evidence that there is a Pt(CN)4(2-) platinum cyanide complex formed. In addition, the Pt-CN band is also observed at 2054 cm(-1). These observed bands provide spectroscopic evidence that the hexacyanoferrate(III) ions dissolve by forming a complex with the surface platinum atoms of the nanoparticles. Raman spectra of the product mixtures are obtained after the completion of the reaction when carried out with higher reactant concentrations to observe the Raman spectra, but with a similar 10:1 ratio of thiosulfate to hexacyanoferrate(III) ions as used previously, with and without PVP-Pt nanoparticles at a correspondingly higher concentration. It is observed that there are no shifts in the characteristic Raman bands associated with hexacyanoferrate(II) ions and no evidence for the formation of adsorbed hexacyanoferrate(II) species or platinum cyanide complexes in the presence of the platinum nanoparticles. In addition, there is evidence for the shifted symmetric SS stretching mode, suggesting that some of the unreacted thiosulfate (present in large excess) is bound to the Pt nanoparticle surface. Thus, under the actual reaction conditions, the hexacyanoferrate(III) ions preferentially react with adsorbed thiosulfate ions to form the reaction products, and this supports the surface catalytic mechanism we proposed previously.     

Effect of 120 MeV Au9+ ion irradiation on the structure and surface morphology of ZnO/NiO heterojunction

ZnO/NiO thin films, each of thickness 100 nm, were deposited on Si(100) substrate by pulsed laser deposition method. The resulting heterojunction, ZnO/NiO/Si, was irradiated by 120 MeV Au⁹⁺ ions and characterized by grazing incidence X‐ray diffraction (GIXRD), Raman spectroscopy, and atomic force microscopy (AFM). The GIXRD confirmed the presence of both NiO and ZnO in the samples. Ion irradiation induced suppression of crystalline nature, and the recrystallization of the same occurred at the fluence of 1 × 10¹³ ions cm⁻². The occurrence of most intense band at 302 cm⁻¹ in Raman spectra corresponds to the symmetric stretching vibration of ZnO. The linear shift of stretching mode of ZnO with ion fluence could be associated with the effect of compressive stress in the material. AFM analysis of the films indicated that the rms roughness increased when the film is irradiated at a fluence of 1 × 10¹² ions cm⁻². Beyond this fluence, the value of roughness decreased up to fluence of 1 × 10¹³ ions cm⁻² and increased thereafter. To see the effect of the stress of buffer layer on the surface layer, we calculated the stress for NiO layer with ion fluence form the lattice parameter. Comparing the stress of buffer layer with roughness of surface layer at the given fluence, we can say that the compressive stress in the buffer layer could possibly control the roughness of the surface layer.     

聚乙炔的离子注入法掺杂

<正> 离子注入是一种物理摻杂方法,在半导体器件的制备中已得到广泛的应用,它与常规的化学、电化学或热扩散掺杂相比具有一些特点:可以通过质量分析器选取单一的注入离子,故掺杂杂质的纯度高;根据注入离子的剂量和能量,精确控制到掺人杂质的数量和深度等等。近年来,采用离子注入技术进行掺杂,改变聚合物或其它绝缘材料表面性质的研究已逐步引起重视真视。     

Raman and FTIR spectra of [Cu(H2O)6](BrO3)2 and [Al(H2O)6](BrO3)3 x 3H2O

Raman and FTIR spectra of [Cu(H2O)6](BrO3)2 and [Al(H2O)6](BrO3)3 x 3H2O are recorded and analyzed. The observed bands are assigned on the basis of BrO3- and H2O vibrations. Additional bands obtained in the region of v3 and v1 modes in [Cu(H2O)6](BrO3)2 are due to the lifting of degeneracy of v3 modes, since the BrO3- ion occupies a site of lower symmetry. The appearance v1 mode of BrO3- anion at a lower wavenumber (771 cm(-1)) is attributed to the attachment of hydrogen to the BrO3- anion. The presence of three inequivalent bromate groups in the [Al(H2O)6](BrO3)3 x 3H2O structure is confirmed. The lifting of degeneracy of v4 mode indicates that the symmetry of BrO3- anion is lowered in the above crystal from C3v to C1. The appearance of additional bands in the stretching and bonding mode regions of water indicates the presence of hydrogen bonds of different strengths in both the crystals. Temperature dependent Raman spectra of single crystal [Cu(H2O)6](BrO3)2 are recorded in the range 77-523 K for various temperatures. A small structural rearrangement takes place in BrO3- ion in the crystal at 391 K. Hydrogen bounds in the crystal are rearranging themselves leading to the loss of one water molecule at 485 K. This is preceded by the reorientation of BrO3- ions causing a phase transition at 447 K. Changes in intensities and wavenumbers of the bands and the narrowing down of the bands at 77 K are attributed to the settling down of protons into ordered positions in the crystal.