CHARACTERIZATION OF CHARGE INJECTION PROCESSES OF THIN FILMS ON INDIUM TIN OXIDE ELECTRODES USING A NOVEL SPECTROELECTROCHEMICAL TECHNIQUE: POTENTIAL-MODULATED ATTENUATED TOTAL REFLECTANCE SPECTROSCOPY

Understanding interfacial charge injection processes is one of the key factors needed for development of efficient organic electronic devices, such as biosensors and energy conversion systems, since these processes control the electrical characteristics of these devices. Spectroelectrochemical characterization of electron transfer processes occurring at the electrode - electroactive thin film interface has been evaluated to improve our understanding of charge transfer kinetics using a novel form of electroreflectance spectroscopy, potential-modulated attenuated total reflectance (PM-ATR), which makes it possible to sensitively monitor spectroscopic changes in thin films as a function of applied potential.PM-ATR was used to evaluate three different redox-active films deposited on indium tin oxide (ITO) electrodes to investigate: i) the orientation dependence of charge transfer rates of thin films of biomolecules, ii) surface treatment and modification effects on charge transfer kinetics of conducting polymers and, iii) estimation of rates of electron injection and conduction band edge of semiconductor nanocrystalline materials.First, Prussian blue film as a model system was used successfully to examine the PM-ATR technique for determination of the charge transfer rate constant between ITO and a molecular film.Second, an anisotropic and redox active protein film, cytochrome c, was used to probe charge transfer rates with respect to molecular orientation. The electron transfer rate measured using TM polarized light was four-fold greater than that measured using TE polarized light. These data are the first to correlate a distribution of molecular orientations with a distribution of electron transfer rates in a redox-active molecular film.Third, the effects of ITO surface treatment and modification on charge transfer kinetics on a conducting polymer, poly(3,4-ethylenedioxythiophene/)/poly(styrenesulfonate) (PEDOT/PSS), were studied. The apparent interfacial charge transfer rate constant for PEDOT/PSS on ITO has been reported for the first time which cannot be measured otherwise with conventional electrochemistry due to high non-Faradaic background of PEDOT/PSS films.Fourth, PM-ATR enabled characterization of reversible redox processes between submonolayer coverages of surface-tethered, CdSe nanocrystals and ITO for the first time. Optically determined onset potentials for electron injection were used for estimation for the conduction band and valance band energies (ECB and EVB, respectively)

The mediational role of intimate partner acceptance and psychological adjustment in the relationship between intimate partner control and marital adjustment

Grounded in Interpersonal Acceptance-Rejection Theory (IPARTheory), this exploratory study investigated the associations among perceived intimate partner rejection, intimate partner control, psychological maladjustment, and marital adjustment. Perceived behavioral control in intimate partner relationships has been under-researched within the context of IPARTheory. Although the role of behavioral control in child/adolescent-parent relationships has been well-established, insufficient exploration of the phenomenon in marriage relationships calls for new empirical findings. The conveniently selected sample consisted of 624 (360 female, 264 male) married individuals living in big cities of Turkey. Intimate Partner Acceptance-Rejection/Control Questionnaire, Personality Assessment Questionnaire, Dyadic Adjustment Scale, and Demographic Form were utilized to gather data. Structural Equation Modeling was utilized as the primary analysis to test the proposed sequential mediational model of the study. The results indicated that intimate partner behavioral control was significantly and indirectly associated with marital adjustment through the mediating effects of intimate partner rejection and psychological maladjustment. Moreover, intimate partner rejection had direct effects on psychological maladjustment and marital adjustment. The indirect effect of intimate partner rejection on marital adjustment via the mediation of psychological maladjustment was found to be significant. Lastly, the sequential mediation by intimate partner rejection and psychological maladjustment in the relationship between intimate partner control and marital adjustment was also significant. This study adds to the existing literature on IPARTheory by showing that perceived intimate partner behavioral control is quite negatively related to marital adjustment. Results underscore how perceived behavioral control by a spouse triggers rejection and diminishes the psychological adjustment of the controlled partner

Potential-Modulated Attenuated Total Reflectance Characterization of Charge Injection Processes in Monolayer-Tethered CdSe Nanocrystals

Reversible electron injection into pyridine-capped CdSe nanocrystals (pyr-CdSe NCs), tethered to indium−tin oxide (ITO) substrates using mercaptoalkylcarboxylic acids, is characterized using attenuated total reflectance (ATR) spectroelectrochemistry on a planar waveguide. The sensitivity of this technique provides for characterization of redox processes in submonolayer films of pyr-CdSe NCs. Optically determined onset potentials for electron injection, measured as bleaching/recovery of the exciton absorption band, provide estimates for the conduction band edge (<i>E</i>_CB). Potential-modulated attenuated total reflectance (PM-ATR), in which the in-phase and out-of-phase reflectance response is measured as a function of modulation frequency, provides estimates for rates of electron injection. These apparent rate constants are found to be nearly independent of tether chain length, suggesting that communication between tethered NCs and electrochemically less active (i.e., less conductive) regions on the ITO surface is rate-limiting