The optical absorption properties of (poly)aromatic hydrocarbons occluded in a nanoporous environment were investigated by theoretical and experimental methods. The carbonaceous species are an essential part of a working catalyst for the methanol-to-olefins (MTO) process. In situ UV/Vis microscopy measurements on methanol conversion over the acidic solid catalysts H-SAPO-34 and H-SSZ-13 revealed the growth of various broad absorption bands around 400, 480, and 580 nm. The cationic nature of the involved species was determined by interaction of ammonia with the methanol-treated samples. To determine which organic species contribute to the various bands, a systematic series of aromatics was analyzed by means of time-dependent density functional theory (TDDFT) calculations. Static gas-phase simulations revealed the influence of structurally different hydrocarbons on the absorption spectra, whereas the influence of the zeolitic framework was examined by using supramolecular models within a quantum mechanics/molecular mechanics framework. To fully understand the origin of the main absorption peaks, a molecular dynamics (MD) study on the organic species trapped in the inorganic host was essential. During such simulation the flexibility is fully taken into account and the effect on the UV/Vis spectra is determined by performing TDDFT calculations on various snapshots of the MD run. This procedure allows an energy absorption scale to be provided and the various absorption bands determined from in situ UV/Vis spectra to be assigned to structurally different species.

Sulfonphthaleine dyes are an important class of pH indicators, finding applications in novel (textile) sensors. In this paper, we present a combined experimental and theoretical study to elucidate the halochromic behaviour of a large set of sulfonphthaleine compounds. Starting from an experimental analysis consisting of UV/Vis spectroscopy, the pH region and the absorption wavelengths related to the colour shift are obtained and pK a values are derived. The effect of the substituents on the pH region can be traced back to their electron donating/withdrawing properties. Time-Dependent Density Functional Theory (TD-DFT) is able to adequately produce the trend in experimental wavelengths. Proton affinities are used to assess the effect of substituents on the pH region. The combination of theory and experiment is able to give a better understanding of the pH sensitivity; the methodology in this work will be useful in future dye design and is applicable to other dye classes as well.

Highlights pH-sensitive PCL and PCL/chitosan nanofibres are successfully electrospun. pH-sensitive PCL and PCL/chitosan nanofibres show a clear halochromic response. Chitosan addition results in a significantly increased water sorption. Chitosan addition is indispensable for a sensitive and rapid response. Theoretical modelling on the dye-polymer interactions underpins the experimental findings. Highlights (for review)Polycaprolactone and polycaprolactone/chitosan nanofibres functionalised with pH- Polycaprolactone (PCL) is an aliphatic polyester, often used in (bio)medical applications 56 because of its biocompatibility, slow biodegradability, low-cost, non-toxicity and good 57 mechanical properties (Moghe et al., 2009; Van der Schueren et al., 2011). However, PCL is Prabhakaran et al., 2008;Yang et al., 2009; Bhattarai et al., 2009; Hong & Kim, 2011; 63 Cooper et al., 2011). Contact angle measurements were carried out with the drop-shape analysis system DSA 10- 168Mk2, coupled to a control unit G120 Mk1/G140-Mk1 and with the drop-shape analysis 169 software DSA1 (v1.80, Krüss). 171Dynamic Vapour Sorption (DVS) measurements were conducted in a Q-5000SA instrument 172(TA-instruments, Zellik, Belgium). All measurements were performed at 23 °C ± 0.1 °C. 173Deliquescent salts (sodium bromide and potassium chloride) were used to verify the humidity 174 of the instrument. 4 mg of nanofibres were placed in the quartz sample pans. At the start of 175 each moisture sorption cycle, the fibres were dried at 0 % relative humidity (RH) until the 176 weight change was stabilised to be less than 0.05 % for a period of 15 minutes. After the 177 stabilisation, the moisture sorption cycle was started and the humidity was increased hydroxide were used to adjust the pH. 196The UV-Vis spectra were recorded with a Perkin-Elmer Lambda 900 spectrophotometer. For suggests an increased interaction with water when chitosan blend nanofibres are used. 287As a final step prior to the halochromic study, the dye leaching of the samples is 288 characterised ( The nanofibrous samples were all yellow just after the electrospinning process, in agreement 306 with the acidic conditions during their production (acetic acid-formic acid solvent system). compared to the sharp transition of NY in aqueous solutions, which occurs between pH 6 and 346 8 (Fig. 3a), the response of PCL nanofibres is less sensitive (response between pH 4 and 10, observed. All PCL/chitosan samples showed a sharp transition between pH 4 and 6 (Fig. 3c). 362Also the wavelength maxima did not alter and remained constant at 474 nm and 605 nm in proposed, which will then be validated by theoretical results. After electrospinning pure PCL (Fig. 5b) with NY, no halochromic behaviour is observed, structures. The chitosan model (Fig. 5e) has a PA of 908 kJ/mol, which is much higher than 429 the value of 841 kJ/mol obtained for the PCL model (Fig. 5d). This suggests that the chitosan ( Fig. 7) is much higher, -132.3 kJ/mol. The value for dye leaching was, however, much larger...

AbstractpH‐Sensitive dyes are increasingly applied on polymer substrates for the creation of novel sensor materials. Recently, these dye molecules were modified to form a covalent bond with the polymer host. This had a large influence on the pH‐sensitive properties, in particular on the acidity constant (pK a). Obtaining molecular control over the factors that influence the pK a value is mandatory for the future intelligent design of sensor materials. Herein, we show that advanced molecular dynamics (MD) methods have reached the level at which the pK a values of large solvated dye molecules can be predicted with high accuracy. Two MD methods were used in this work: steered or restrained MD and the insertion/deletion scheme. Both were first calibrated on a set of phenol derivatives and afterwards applied to the dye molecule bromothymol blue. Excellent agreement with experimental values was obtained, which opens perspectives for using these methods for designing dye molecules.

Stereotype priming can lead to assimilation or contrast effects on behavior. We argue that self-activation is a moderator of both assimilation and contrast effects. To test this hypothesis, in two studies, we activated independent or interdependent self-knowledge before priming participants with the dumb Blonde stereotype or a control category (Study 1) or no prime (Study 2). Participants then answered a knowledge test. Results support our expectations: Participants presented assimilation under interdependence (i.e., underperformance compared to control group) while they presented no assimilation (i.e., comparable performance with control group in Study 1) and contrast (better performance than control group in Study 2) under independence. We discuss implications of these findings in regards of previous research and recent models such as the Active

The halochromism in solution of a prototypical example of an azo dye, ethyl orange, was investigated by using a combined theoretical and experimental approach. Experimental UV/Vis and Raman spectroscopy pointed towards a structural change of the azo dye with changing pH value (in the range pH 5-3). The pH-sensitive behavior was modeled through a series of ab initio computations on the neutral and various singly and doubly protonated structures. For this purpose, contemporary DFT functionals (B3LYP, CAM-B3LYP, and M06) were used in combination with implicit modeling of the water solvent environment. Static calculations were successful in assigning the most-probable protonation site. However, to fully understand the origin of the main absorption peaks, a molecular dynamics simulation study in a water molecular environment was used in combination with time-dependent DFT (TD-DFT) calculations to deduce average UV/Vis spectra that take into account the flexibility of the dye and the explicit interactions with the surrounding water molecules. This procedure allowed us to achieve a remarkable agreement between the theoretical and experimental UV/Vis spectrum and enabled us to fully unravel the pH-sensitive behavior of ethyl orange in aqueous environment.

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Previous studies have shown that consumers with higher affect intensity expressed stronger preferences for softer car seat fabrics (Kergoat et al.). The present research aims to consolidate and expand these results. Across two studies, we attempt to determine whether the intensity of affect (as measured by the affect intensity measure; Larsen) is a more general construct involved in soft textile preferences. Through the evaluation of two product categories (car seat fabrics and washed‐shirt fabrics) and the manipulation of product sensory attributes, we were able to establish that affect intensity components (positive intensity and negative reactivity) play a role in soft textile preferences, independent of the product category. The highest predictive value of particular affect intensity components for softness preference is discussed in line with the multidimensional approach of the affect intensity construct (Bryant et al.). PRACTICAL APPLICATIONS This research highlights the significance of one emotional individual difference dimension (affect intensity) accounting for consumer tactile sensory preferences. Practically, it offers a way to characterize clusters of heterogeneous tactile sensory preferences observed in consumer tests. Furthermore, it represents a step in the understanding of underlying processes involved in soft tactile sensory preferences. We can assume these implications are not limited to the sense of touch and/or non‐food products. As a general emotional variable, the affect intensity construct must play a role in various blind sensory evaluation settings and be a significant tool for a typology of consumers.