Presence Of TBA Research Articles

ZnMn2O4 nanostructures: Synthesis via two different chemical methods, characterization, and photocatalytic applications for the degradation of new dyes

Water pollution have become contentious among researchers. By increasing industrialization, the availability of clean water has been reduced. Industrial dyestuffs contribute to the escalation of environmental pollution and are the largest group of organic compounds. The aim of the present work is the synthesis of nanostructures that accelerate the removal of organic dyes from water. To reach this aim, first, ZnMn2O4 nanostructures were synthesized by hydrothermal and co-precipitation methods using maleic acid and phenylalanine as a capping agent. Second, the nanostructures were characterized. XRD analysis revealed the formation of ZnMn2O4 with diameters about 32.3 nm. SEM analysis showed the formation of the agglomerated spherical ZnMn2O4 nanostructures with diameters lower than 50 nm. EDX analysis confirmed the purity of the prepared samples with the presence of Zn, Mn, and O. FT-IR analysis confirmed the bonding between Mn and O at about 620 cm−1. ZnMn2O4 nanostructures showed antiferromagnetic behaviors due to the super-exchange interactions between manganese ions. Finally, the photocatalytic behavior of the nanostructures was investigated for degradation of the anionic and cationic dyes. The results of the photocatalytic tests of two as-prepared samples via different methods were similar. The results exhibit a promising photocatalytic activity in the presence of 0.03 g photocatalyst for degradation of a dye solution with 10 ppm concentration. We introduced these conditions as optimum conditions and achieved maximum decolorization (92.43 %) in the 10 ppm of MV solution after 90 min. Also, we repeated six consecutive reaction cycles and observed a little activity loss after six reactions. We related this result to the high stability of the photocatalyst. We performed scavenging experiments to evaluate the active species involved in the photocatalytic process and plausible mechanisms. The photocatalytic degradation of MV decreased in the presence of TBA and BQ, respectively. This decrease indicated that OH° and O2°− radicals are important active species in the MV degradation process.

Activation of peroxymonosulfate for degrading ibuprofen via single atom Cu anchored by carbon skeleton and chlorine atom: The radical and non-radical pathways

Single atomic Cu catalysts (SACs Cu@C) anchored by carbon skeleton and chlorine atom was synthesized by hydrolyzing Cu-MOFs and then pickled by aqua-regia to remove Cu nanoparticles (NPs Cu). Comparative characterizations revealed that SACs Cu@C was a hierarchically porous nanostructure and Cu dispersed uniformly throughout the carbon skeletons. With less active components, SACs Cu@C behaved better in activating PMS over NPs Cu@C on ibuprofen removal (91.3 % versus 30.2 % in 30 min). Two Cu coordination environments were found by EXAF and DFT calculation, including four-coordinated Cu with 4C atoms and six-coordinated Cu with 4Cu and 2Cl atoms. The obvious interfacial electron delivery between PMS and SACs Cu@C was found, which was enhanced by Cl atom. Cu(I)/Cu(II) redox cycle would donate electron to peroxy bond of PMS for generating OH, SO4− and O2−. But electron transferred in opposite direction when PMS bonded to Cu atom through its terminal oxygen atom in sulfate, which formed 1O2. IBP degradation proceeded through both radical and non-radical route. IBP degradation was inhibited with the presence of TBA, methanol and furfuryl alcohol but accelerated by p-BQ, which could accelerate OH generation. Two degradation pathways were deducted. This study provided a new insight into catalysts designed for PMS activation.

A Facile Approach for Pt Single Atoms Deposition on Two-Dimensional Calcium Niobate Nanosheets for Photocatalytic Hydrogen Evolution

Single atoms (SAs) have drawn significant attention, because of their enormous catalytic activity and high atom-utilization efficiency. Particularly, for H2 evolution, SAs decorated on two-dimensional (2D) nanosheets have great potential, because of the distinctive advantages offered by 2D materials, such as abundant surface-active sites, high specific surface area, and better-photoexcited charge carrier separation. Despite the significant advantages of 2D materials as support, the deposition of SAs on 2D nanosheets is still a great challenge and rarely has been reported. This work reports the facile deposition of Pt-SAs and Pt-SAs/nanoclusters (NCs) on Ca2Nb3O10 and N-doped Ca2Nb3O10–xNx nanosheets, respectively, via a modified photodeposition method. We observe that the presence of a suitable concentration of tetrabutylammonium (TBA+) ions is essential for the successful deposition of Pt-SAs and Pt-SAs/NC via Pt–O bond formation on Ca2Nb3O10 and Ca2Nb3O10–xNx nanosheets, respectively. The findings of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC HAADF-STEM) validated the successful deposition of Pt-SAs on Ca2Nb3O10 and Pt-SAs/NC on N-doped Ca2Nb3O10–xNx nanosheets, which are further validated via X-ray absorption fine structure (XAFS) spectroscopy. As a result, Ca2Nb3O10-PtSA exhibited excellent H2 production: 280.5 μmol h–1, which is 2.7 and 6.1 times higher, compared to Ca2Nb3O10-PtNP (105.08 μmol h–1) and bare Ca2Nb3O10 (46.05 μmol h–1). Furthermore, N-doped Ca2Nb3O10–xNx-PtSA/NC demonstrated 2.0 and 3.6 times superior H2 evolution, in contrast to Ca2Nb3O10–xNx-PtNP under full-spectrum and visible light irradiation (λ > 420 nm), respectively. Consequently, this work provides a new direction for SAs deposition on exfoliated perovskite nanosheets in the presence of TBA+ ions used during exfoliation, offering a potential strategy that can be applied to a large library of nanosheets synthesized via soft-chemical exfoliation.

An insight into the effects of ratios and temperatures on a tetrabutylammonium bromide and ethylene glycol deep eutectic solvent

Molecular dynamics (MD) simulations were performed to study the structures and properties of a deep eutectic solvent (DES) synthesised from tetrabutylammonium bromide (TBAB) paired with ethylene glycol (EG). Measurements were performed at different mol ratios of TBAB:EG (1:2 to 1:6) and temperatures (303 to 333 K). Upon validation, MD simulations of DES’s density confirmed results to be in good agreement with previously validated experimental density (Maximum Deviation = 3.91%). The effects of different ratios and temperatures on radial distribution function (RDF), spatial distribution function (SDF), hydrogen bonding, mean square displacement (MSD) and self-diffusion coefficient of the TBAB:EG system were investigated. From RDF analysis, it was observed that Br− moved further away from TBA+ and formed a hydrogen bond with the hydroxyl group (OH) on EG at the closest distance of 0.270 nm. The self-diffusion coefficient of TBA+, Br− and EG increased proportionately to EG. High numbers of hydrogen bonds were observed at a high EG ratio as more intermolecular bondings between EG-Br were established. Hence, the introduction of EG molecules significantly affected ionic interaction within the resulting DES and changed its properties. Experimental data from infrared (IR) spectra and NMR were used to show a correlation between the formation of hydrogen-bonded EG-Br as observed in RDF. Increasing temperatures also altered the RDF, MSD and hydrogen bonding properties of the DES. Meanwhile, the main factor determining ionic movement was found to be the presence of TBA, as the ability of its cation’s long alkyl side chain to form clustering ions dictated the behaviour of the liquid. Therefore, the changes in ratios and temperatures in DESs are essential in predicting their properties and subsequently, in ascertaining the industrial applicability of a particular DES. The presented results showed that the studied DES can be used for many applications and suit the requirement for DNA technology, especially for DNA solvating medium.

Ni- and Cu-co-Intercalated Layered Manganese Oxide for Highly Efficient Electro-Oxidation of Ammonia Selective to Nitrogen.

We fabricated a thin film of layered MnO2 whose interlayer space was occupied by hydrated Ni2+ and Cu2+ ions. The process consisted of electrodeposition of layered MnO2 intercalated with tetrabutylammonium cations (TBA+) by anodic oxidation of aqueous Mn2+ ions in the presence of TBA+, followed by ion exchange of the initially incorporated bulkier TBA+ with the denser transition metals in solution. The resulting layered MnO2 co-intercalated with Ni2+ and Cu2+ ions (NiCu/MnO2) catalyzed the ammonia oxidation reaction (AOR) in an alkaline electrolyte with a much lower overpotential than its Ni2+- and Cu2+-intercalated single-cation counterparts. Surprisingly, the NiCu/MnO2 electrode achieved a faradic efficiency as high as nearly 100% (97.4%) for nitrogen evolution at a constant potential of +0.6 V vs Hg/HgO. This can be ascribed to the occurrence of the AOR in the potential region where water is stable and dimerization of the partially dehydrogenated ammonia species is preferred, thereby forming an N-N bond, rather than to be further oxidized into NOx species.

Surface Modification of Layered Perovskite Nanosheets with a Phosphorus Coupling Reagent in a Biphasic System.

Oleyl phosphate-modified HLaNb2O7· xH2O nanosheets (OP_HLaNb nanosheets) were prepared via phase transfer from an aqueous phase, comprising a dispersion of HLaNb2O7· xH2O (HLaNb) nanosheets, formed through the intercalation of tetrabutylammonium ion (TBA+) in the interlayer space of HLaNb and subsequent delamination, to a cyclohexane phase containing oleyl phosphate (OP, a mixture of monoester and diester). The modification of HLaNb nanosheets with OP was essentially completed within 3 days at a pH value of 2 or 4. Both infrared and solid-state 13C cross-polarization and magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of the OP_HLaNb nanosheets showed the presence of OP and/or related species and TBA+ on the HLaNb nanosheet surface. The solid-state 31P MAS NMR spectra of OP_HLaNb nanosheets exhibited new signals at -2 and 0 ppm, the former of which indicates the formation of Nb-O-P bonds. These whole data set obtained by complementary techniques clearly point out the modification of the HLaNb nanosheet surface by OP moieties causing a phase transfer. OP_HLaNb nanosheets showed higher dispersibility in cyclohexane than the OP_HLaNb_interlayer nanosheets, which were prepared via stepwise substitution reactions in the interlayers of HLaNb to achieve surface modification with OP and subsequent exfoliation in cyclohexane. The presence of TBA+ on the HLaNb nanosheets and the use of a liquid-liquid biphasic system were likely to improve the dispersibility. These results show that the preparation of OP-modified HLaNb nanosheets which could be well-dispersed in the cyclohexane phase was successful because of the use of a liquid-liquid biphasic system.

Hydrate Equilibrium Measurements for CH4 and CO2/CH4 Mixture in the Presence of Single 2-Methyl-2-propanol and 1,1-Dichloro-1-fluoroethane

Hydrate phase equilibrium conditions of CO2/CH4 + 2-methyl-2-propanol (tBA) + water system, CH4 + 1,1-dichloro-1-fluoroethane (HCFC-141b) + water system, CO2 + HCFC-141b + water system, and CO2/CH4 + HCFC-141b + water system were measured. The moles fraction of CO2 in the mixture gases were 0.33 and 0.5, respectively. The mole fraction of HCFC-141b and tBA were 0.056. The measured temperature range is from 283.0 to 294.2 K. The phase equilibrium conditions were tested by an isochoric pressure-search method. Results showed that HCFC-141b has a stronger promotion effect on CH4 hydrate formation than on CO2 hydrate. The effect of CO2 content on the phase equilibrium conditions of CO2/CH4 mixture + HCFC-141b + water is weak. tBA also acts as a promoter for CO2/CH4 mixture gas. In the presence of tBA, the phase equilibrium conditions of the system with higher CO2 content moved to higher pressure and lower temperature region compared with the system with lower CO2 content.

Tetrabutylammonium cations for moisture-resistant and semitransparent perovskite solar cells

Tetra-butylammonium cations have been partially substituted for methylammonium cations in perovskite thin films. The stability of devices stored under ambient conditions was enhanced by the presence of TBA and cells with high mol% TBA were found to have reasonable efficiencies while being semi-transparent.

Effects of 4-tert-butylpyridine on the quasi-Fermi levels of TiO2 films in the presence of different cations in dye-sensitized solar cells

The effects of additives on the quasi-Fermi levels (QFL) of TiO(2) films in dye-sensitized solar cells (DSCs) were investigated by a direct method. We observed that the values of QFL of TiO(2) at short circuit and open circuit are different and found for the first time the linear relationships between QFL shifts at short circuit and open circuit induced by 4-tert-butylpyridine (TBP), and that the slopes of the lines were significantly influenced by the nature of cations in the electrolyte. Different QFL shifts at short circuit and open circuit were observed in the presence of TBA(+). These quantitative results suggest that the QFL of TiO(2) films at short circuit and open circuit can be adjusted separately by developing suitable additives and cations, which will be helpful to further improve the efficiency of DSCs.

Pseudo-homogeneous micelle extraction of ion-associates formed between tetrabutylammonium ion and some aromatic sulfonate ions into nonionic surfactant micelle studied through the mobility measurements in capillary zone electrophoresis

Ion-association extraction of some aromatic sulfonate ions including alkylbenzene sulfonates with tetrabutylammonium ion (TBA +) into nonionic surfactant micelle has been investigated through the changes in the electrophoretic mobility. Nonionic surfactants of Brij 35 and Brij 58 were used as micelle substrates to which the ion-associates formed could distribute. The electrophoretic mobility of the aromatic sulfonate ions was measured by capillary zone electrophoresis in the presence of TBA + and/or the nonionic surfactant to determine ion-association constants ( K ass), binding constants of the anions to the nonionic surfactant micelle ( K B), and binding constants of the ion-associates to the nonionic surfactant micelle ( K B,IA). Nonlinear phenomena induced with the alkyl chain moiety were observed on K ass and K B by its linear structure and the mixed micelle formation, respectively. Larger K B values were obtained with Brij 58 as micelle matrix than with Brij 35, while the differences in K B,IA were small between Brij 58 and Brij 35.

Ion-association extraction of nitrophenolate ions with tetrabutylammonium ion into nonionic surfactant micelle

Ion-association extraction of some nitrophenolate ions with tetrabutylammonium ion (TBA +) into nonionic surfactant micelle has been investigated through the changes in the electrophoretic mobility. Nonionic surfactants of Brij 35 and Brij 58 were used as micelle substrates to which the ion-associates formed could distribute. The electrophoretic mobility of the phenolate ions was measured by capillary zone electrophoresis in the presence of TBA + and/or the nonionic surfactant. The electrophoretic mobility of the analyte anions decreased with increasing concentrations of the interacting reagent. Ion association constants ( K ass) between TBA + and the phenolate ions, as well as binding constants of the anions to the nonionic surfactant micelle ( K B), were determined through the mobility change by applying it to a non-linear least-squares analysis. Binding of the ion-associates was also observed from the aqueous phase to the micelle phase, when both TBA + and the nonionic surfactant are present. Binding constants of the ion-associates to the nonionic surfactant micelle ( K B,IA), as well as micelle extraction constants of the ion-associates ( K ex,m), were also determined by using the mobility change. The K ex,m values obtained were compared with the ion association-solvent extraction constants ( K ex,S) between water and chloroform.

Sorption of Lanthanum, Terbium, and Erbium Complexes of Some Mono- and Bisazoderivatives of Chromotropic Acid in the Presence of Surfactants

Optimal conditions were found for the sorption of lanthanum, terbium, and erbium complexes of some derivatives of chromotropic acid: Arsenazo II, Arsenazo III, Carboxyarsenazo, and Chlorophosphonazo III on Silochrom C-120 silica gel in the presence of tetrabutylammonium bromide (TBA). Diffuse reflection coefficients and molar coefficients of the chromaticity functions of the adsorbates were determined. It was demonstrated that the preconcentration of complexes on the solid matrix in the presence of TBA increases the sensitivity of the determination of rare-earth elements by a factor of 5–50 in comparison with solutions; the use of chromaticity characteristics further increases the sensitivity by 1.5–2 orders of magnitude.

Aerobic biodegradation of gasoline oxygenates MTBE and TBA

MTBE degradation was investigated using a continuously stirred tank reactor (CSTR) with biomass retention (porous pot reactor) operated under aerobic conditions. MTBE was fed to the reactor at an influent concentration of 150 mg/l (1.70 mmol/l). A second identical reactor was operated as a control under the same conditions with the addition of 2.66 g/l of sodium azide, to kill any biological activity. Results from these experiments suggest that biomass retention is critical to the degradation of MTBE. The rate of MTBE removal was shown to be related to the VSS concentration. MTBE removal exceeded 99.99% when the VSS concentration in the reactor was over 600 mg/l. Results obtained from batch experiments conducted on mixed liquor samples from the porous pot reactor indicate that the individual rates of biodegradation of MTBE and TBA were higher for initial concentrations of 15 mg/l than for concentrations of 5 mg/l. The presence of TBA at lower concentrations did not effect the rate of MTBE degradation, however higher concentrations of TBA did reduce the rate of biodegradation of MTBE. Denaturing Gradient Gel Electrophoresis (DGGE) analysis reveals that the culture consisted of a community of bacterial organisms of about 6 species.

Equilibrium Study on the Ion Association of Monovalent and Divalent Naphtholsulfonates with Tetrabutylammonium Ion in an Aqueous Solution by Capillary Zone Electrophoresis

The ion-association properties of monovalent and divalent naphtholsulfonate ions were investigated with tetrabutylammonium ion (TBA(+)) as a pairing ion in an aqueous solution. The ion-association constants were obtained by analyzing the change in the electrophoretic mobility of naphtholsulfonate ions in the presence of TBA+ by capillary zone electrophoresis; also, the contribution of a hydroxyl group to the ion associability of monovalent and divalent naphtholsulfonate ions, as well as the electrophoretic mobility of the ions, was investigated. The obtained ion-association constants indicate that the positional isomers possessing anionic groups at the β-position of the naphthalene ring are more associable with TBA(+) than those at the α-position, and that the ion associability of the divalent naphtholsulfonates is larger than those of the monovalent ones, except for 1-naphthol-2-sulfonate. The abnormal associability of 1-naphthol-2-sulfonate can be explained by a synergistic increase in the hydrophilicity of the divalent ion. The difference in the ion associability between the monovalent and divalent naphtholsulfonates, 0.16 in log unit on the average, was smaller than that between the naphthalenesulfonate and naphthalenedisulfonate ions, 0.30 log unit on the average. The electrophoretic mobility of the naphtholsulfonate ions obtained in the absence of TBA(+) is compared with each other, and the contribution of the hydroxyl group is discussed on the basis of the hydration behavior of the naphtholsulfonates.

Solvent Extraction of Silver(I) as Anionic Metal Complexes with 2-Thenoyltrifluoroacetone and 4-Isopropyltropolone into Chloroform in the Presence of Tetrabutylammonium Ions.

The solvent extraction of silver(I) in aqueous 0.1 mol dm-3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) and 4-isopropyltropolone (β-isopropyltropolone, Hipt) into chloroform was studied in the absence and presence of tetrabutylammonium ions (tba+), and the results were compared. Although extraction with Htta was poor, it was very much enhanced and nearly quantitative extraction was achieved by the addition of tba+. This was assumed to be due to the fact that the complex, Ag(tta), was hydrophilic due to its hydration, but tba+Ag(tta)2-, which was extracted in the presence of tba+, was very weakly hydrated and bulkier. Both Ag(ipt) and Ag(ipt)(Hipt) were extracted; extraction with Hipt was not very effective in the absence of tba+ By the addition of tba+, the anionic complex, tba+Ag(ipt)2, was also extracted, and nearly quantitative extraction was also achieved. Since the formation of this anionic complex is made by an exchange of ipt- with Hipt of the Ag(ipt)(Hipt) species, the enhancement of extraction was impaired by the dissociation of Hipt from the self-adduct.

Dependence of swelling behaviour and electrochemical activity of water-soluble polythiophene films on the nature of the electrolyte

Abstract Electrochemical activity of a cast film of a water-soluble polythiophene, poly(3-(3′-thienyl)propanesulphonic acid) (PTS), is examined in various electrolyte solutions. The PTS film is electroactive in 0.1 M tetra(n-butyl)ammonium perchlorate (TBAClO4) + acetonitrile. In contrast, the film is inactive in 0.1 M LiClO4 + acetonitrile, even in the presence of TBA+, while addition of water (above 0.1 M) activates it. These characteristics are related to the film swelling; the PTS film is electroactive only when it is swollen. Water swells the film rapidly and TBA+ swells the film much more gradually. In the 0.1 M TBAClO4 + acetonitrile, potential cycling accelerates the film swelling owing to break-in behaviour. Well-swollen films do not exhibit break-in.

Characterization of endothelium-derived hyperpolarizing factor as a cytochrome P450-derived arachidonic acid metabolite in mammals.

1. In addition to nitric oxide (NO) and prostacyclin (PGI2) an as yet unidentified endothelium-derived hyperpolarizing factor (EDHF) contributes to the dilator effect of bradykinin in different vascular beds. We have investigated the nature and mechanism of action of this factor in freshly isolated bovine and porcine coronary artery segments which were preconstricted with the thromboxane mimetic U46619 (9,11-dideoxy-11 alpha, 9 alpha-epoxymethano-prostaglandin F2 alpha, 10-30 nM). 2. The concentration-response curve of bradykinin was significantly shifted to the right after inhibition of NO synthesis with NG-nitro-L-arginine (L-NNA, 30 microM), whereas cyclo-oxygenase blockade with diclofenac (1 microM) had no effect. Preconstriction of the segments with potassium chloride (40-60 mM) completely abrogated the NO/PGI2-independent dilator response to bradykinin. In sandwich bioassay experiments, both the luminal and abluminal release of NO, but not that of EDHF, was readily detectable. 3. Inhibitors of Ca(2+)-activated K+ channels (K+Ca), such as apamin (1 microM) and tetrabutylammonium (TBA, 3 mM), strongly attenuated the EDHF-mediated bradykinin-induced relaxation, while glibenclamide (3 microM), an inhibitor of K+ATP channels, had no effect. 4. These relaxations were also significantly inhibited by the phospholipase A2 inhibitor, quinacrine (30 microM), and the cytochrome P450 inhibitors, SKF525a (30-100 microM) and clotrimazole (100 microM). Moreover, incubation of endothelium-denuded coronary artery rings with a cytochrome P450-derived arachidonic acid metabolite, 11,12-epoxyeicosatetraenoic acid, elicited a concentration-dependent (1-10 microM) dilatation which was abolished both in the presence of TBA (3 mM) and following preconstriction of the segments with potassium chloride instead of U46619.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxidation of Cerium(III) during Solvent Extraction with Benzoyltrifluoroacetone into Carbon Tetrachloride in the Absence and Presence of Tetrabutylammonium Ions

Cerium(III) in aqueous 0.1mol dm-3 sodium nitrate solutions was extracted with benzoyltrifluoroacetone (Hbfa) into carbon tetrachloride in the absence and presence of tetrabutylammonium (tba+). In the absence of tba+, only the Ce(bfa)3 was extracted; in its presence, however, not only was the ternary complex (Ce(bfa)4-tba+) also extracted, and the extraction was much better. When the two-phase agitation was continued, the organic phase gradually changed from colorless to brown in the absence of tba+ due to the oxidation of the metal ions in the complex in the organic phase to the cerium(IV). However, in the presence of tba+, the organic phase remained colorless for a long time and, thus, oxidation of the cerium(III) was negligible. The rate of oxidation of cerium(III) in the Ce(bfa)3 complex in carbon tetrachloride to the cerium(IV) by forming the Ce(bfa)4 complex was measured by spectrophotometry. The rate of this oxidation was found not to be affected by the ligand concentration.

Tetrathiafulvalene- and dithiafulvene-substituted mesitylenes, new .pi.-donor molecules with 3-fold symmetry and the formation of an unprecedented new class of electroactive polymers

Novel π-donor molecules with 3-fold symmetry are built on the 1,3,5-benzene core, substituted with three identical moieties, i.e. -CH=H(TTF) (8) (TTF=tetrathiafulvalene), -CH 2 S((TTF)Me 3 ) (9), 1,4-dithiafulven-6-yl (10a,b), and 6-methyl-1,4-dithiafulven-6-yl (11a,b). Cyclic voltammetry experiments demonstrate that oxidation of 10a,b gives rise to the precipitation of an electroactive polymer on the electrode, while 9 can be reversibly oxidized to 9 3+ and 9 6+ . Electrocrystallization of 9 in the presence of TBA 2 (Mo 6 Cl 14 ) affords crystals of (9 2+ ).Mo 6 Cl 14 2- , whose magnetic properties are investigated by EPR

Electrochemistry of fullerene (C60) films: quartz crystal microbalance and mass spectrometric studies

The incorporation of tetra-n-butylammonium (TBA{sup +}) upon electroreduction of films of C{sub 60} on an electrode in MeCN solutions was studied by electrochemical quartz crystal microbalance (EQCM) and laser desorption mass spectrometry (LDMS) methods. EQCM allowed estimation of the extent of dissolution of the films upon reduction to the C{sup 60}{sup {minus}} and C{sub 60}{sup 2{minus}} forms and the increase in mass caused by incorporation of TBA{sup +}. LDMS analysis also indicated the presence of TBA{sup +} after reduction. Both methods suggested that TBA{sup +} remains in the lattice after reoxidation of the reduced forms to C{sub 60}, indicating a new type of {open_quotes}ionic charge trapping{close_quotes} in these films.