MD Calculations Research Articles

Impact of Surface Functionalization of Pt/Graphitized Carbon on Catalyst Layer Structure and PEMFC Performance

The understanding of catalyst layers (CL) structure is of great importance to reduce Pt loading in a MEA of PEM fuel cell. Recent studies have shown that the CL structure is largely dependent on ionomer microstructure, affecting Pt utilization by controlling reactant transport [1]. The ionomer microstructure such as the distribution of ionomer thin film in the CL can be controlled by introducing functional groups on the carbon support to tune the interaction between PFSA ionomers and carbon supports, which was demonstrated by MD calculation [2] as well as experimental MEA study [3]. We have tried to introduce the surface functional groups to the Pt loaded highly graphitized carbon supports using non-covalent approaches [4] to resolve the non-uniform ionomer distribution issue, particularly in highly graphitized carbon-based catalysts. The pyrene aromatic compounds with different functional groups to form different surface charge were applied to the Pt/C commercial catalyst, and the surface modified catalysts were fabricated to cathode CL of MEAs through decal process. The MEA performance evaluated in a single cell showed that the Pt/C catalyst modified with amine groups performs better than the catalyst modified with other functional groups and non-functionalized reference catalyst. The reason of better MEA performance of the surface modified Pt/C catalyst will be discussed in terms of better ionomer distribution in the CL. In addition, the issues affecting the MEA performance such as the Pt poisoning by the functional groups during the non-covalent functionalization of Pt/C will also be presented. [1] F. C. Cetinbas, R. K. Ahluwalia, N. Kariuki, V. D. Andrade, D. Fongalland, L. Smith, J. Sharman, P. Ferreira, S. Rasouli, D. J. Myers, J. Power Sources 344 (2017) 62. [2] T. Mashio, A. Ohma, T. Tokumasu, Electrochim. Acta 202 (2016) 14. [3] A. Orfanidi, P. Madkikar, H. A. El-Sayed, G. S. Harzer, T. Kratky, H. A. Gasteiger, J. Electrochem. Soc. 164 (2017) F418. [4] H.-S. Oh, H. Kim, Adv. Funct. Mater 21 (2011) 3954.

A combined electrochemical and theoretical analysis of environmentally benign polymer for corrosion protection of N80 steel in sweet corrosive environment

Abstract The corrosion inhibition efficiency of aniline, formaldehyde and piperazine based polymer (ADPD) on N80 steel in 3.5% NaCl solution saturated with carbon dioxide was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, weight loss, scanning electrochemical microscopy (SECM), scanning electron microscopy (SEM) measurements, density functional theory (DFT) and molecular dynamics simulation (MD). The adsorption of polymer onto N80 steel surface followed Langmuir adsorption isotherm model. Potentiodynamic polarization study confirmed that inhibitor is mixed type with cathodic predominance. SECM study reveals the current values decreases with the increasing concentration of polymer. SEM study supports the smooth metal surface texture. DFT and MD calculations are in agreement with the experimental findings.

Energetics of melting of Yb2O3 and Lu2O3 from drop and catch calorimetry and first principles computations

The energetics of melting of Yb2O3 (Tfus 2707 ± 20 K) and Lu2O3 (Tfus 2762 ± 15 K) were studied experimentally by drop-and-catch (DnC) calorimetry and computationally by ab initio molecular dynamic (AI MD) techniques. Fusion enthalpies for Yb2O3 (102 ± 10) kJ∙mol−1 and Lu2O3 (125 ± 10) kJ∙mol−1 were derived from the steps in enthalpy increments from DnC experiments performed on liquid and solid samples laser heated in an argon flow. Fusion enthalpy values for Yb2O3 and Lu2O3 obtained from AI MD computations were 124 ± 2 kJ/mol and 124 ± 3 kJ/mol, respectively. High temperature heat capacity values for solid and liquid phases and volume change on melting were obtained from AI MD. Computed volume change on melting for both oxides is less than 1%, prompting an experimental investigation due to difference with prior experimental results. Experimental results indicate substantial dissolution of oxygen in liquid Lu2O3.

Responsive Nanoporous Membranes with Size Selectivity and Charge Rejection from Self-Assembly of Polyelectrolyte "Hairy" Nanoparticles.

We report the preparation and characterization of charged nanoporous membranes by self-assembly of "hairy" silica nanoparticles (HNPs) functionalized with polyelectrolyte copolymer brushes. We show that HNP membranes possess high water flux, have well-defined pore sizes, and rejection up to 80% of charged species in solution. The properties of these membranes can be tuned by controlling the length and composition of polymer brushes and the electrolyte concentration in solution. We demonstrate that membrane pore sizes undergo changes of up to 40% in response to changes in the ionic strength of the salt solution. Using MD computer simulations of a coarse-grained model, we link these tunable properties to the conformations of polymer chains in the spaces between randomly packed HNPs. As polymer length increases, the polymers fill the interparticle gaps, and the pore size decreases markedly. On the basis of their straightforward fabrication and tunable properties, HNP membranes may find applications in size- and charge-selective separations, water desalination, and responsive devices.

In silico study on core-shell pseudodendrimeric glycoside structures in drug delivery related usages

Different glycoside based pseudodendrimeric (PD) structures were investigated computationally by using molecular dynamics approach. Studying were done at 37 and 42 °C to evaluate the response of the systems to the temperature. The monomers were attached to the C60 to create G4–6 structures. Studying Rg values cleared that structures show a response to the temperature. Between the G4 structures idose, lyxose, and mannose are showing an expansion by increasing temperature. In G5 structures, altrose, arabinose, and ribose are acting in that way. The glucose, lyxose, ribose, talose, and xylose in G6 structures are the best from the expansion of structure by increasing of temperature point of view. Considering these statements, the lyxose and ribose are more potent to show expansion by increasing temperature that is the desired behavior in temperature stimuli drug delivery approach. Also, it was found that there is a direct relation between the number of the hydrogen bonding interactions and compactness of structure. The layer based Rg values showed that G5 and G6 are showing the most amount of back-folding behavior. Molecular dynamic (MD(simulation studied and molecular mechanics/generalized Born surface area (MM/GBSA) calculations were used to study the release of seven drugs including afatinib, alitretinoin, altretamine, azacitidine, bexarotene, bicalutamide, and chlorambucil via temperature-responsive manner by using lyxose- and ribose-PDs. The results showed that G4 of ribose-PD is suitable for the release of afatinib, altretamine, and bicalutamide. The G5 of lyxose-PD can be used for the release of azacitidine and chlorambucil. The G6 of lyxose-PD and G5 of ribose-PD are appropriate for the release of alitretinoin and bexarotene, respectively. The van der Waals and electrostatic interactions and not the hydrogen bonding one is playing roles on the tighter and looser attachment of drugs to the PDs at lower and higher temperatures respectively. By considering the presented results, it is possible to select the suitable PDs for delivery of a drug by comparing the structure of the target drug with the drugs that have been studied in the present study. It can reduce the time and money that should be used to perform the experimental studies.

Formation Conditions for Epitaxial Graphene on Diamond (111) Surfaces

The phase transformation from a non-terminated diamond (111) surface to graphene has in the present study been simulated by using ab initio MD calculations at different temperatures and under various reaction conditions. For strict vacuum conditions, the graphitization process was observed to start at about 800 K, with a final graphene-like ad layer obtained at 2500 K. The C-C bonds across the interface were found to be broken gradually with an increase in temperature. The resulting graphene-like ad layer at 2500 K was observed to chemisorb to the underlying diamond surface with 33% of the initial C-C bonds, and with a C-C covalent energy value of 3.4 eV. The corresponding DOS spectra showed a p-doped character, as compared with graphene. When introducing H radicals during the annealing process, a graphene-like ad layer started to be formed at a much lower temperature; 500K.The completeness of the diamond-to-graphene process was found to strongly depend on the concentration of H radicals. When introducing a larger concentration of H radicals into the lattice in the initial part of the annealing process, the formation of a free-standing graphene layer was observed to take place at an even lower H concentration and temperature (1000 K).

Assessment of sub-surface damage during machining of additively manufactured Fe-TiC metal matrix composites

This study is concerned with investigating the effect of laser assisted machining (LAM) on sub-surface damage during turning of iron-titanium carbide metal matrix composite (MMC) manufactured through laser direct deposition. Localized heating of the Fe-TiC workpiece via a CO2 laser ahead of the cutting tool has been shown to be effective in reducing sub-surface debonding by approximately 20%. The dynamic behavior of the MMC under cutting has been explored with the help of a 3D multi-scale nose turning simulation model. The implementation of the multi-scale model has been realized through a hierarchical multi-scale modeling methodology where the traction separation response of Fe-TiC interface determined from MD calculations has been coupled to the cohesive zone model in the finite element simulations. The fidelity of the multi-scale model has been tested by comparing the macro and micromechanical responses of the MMC during laser assisted machining. With the help of the simulation model, it has been discovered that the particles plough through the matrix material due to which their concentration increases ahead of the cutting tool. This contributes to the dynamic loading of the machined workpiece in addition to loading from the secondary cutting edge of the tool. These two mechanisms collectively contribute towards sub-surface damage in the machined metal matrix composites.

Spontaneous Breaking and Remaking of the RS–Au–SR Staple in Self-assembled Ethylthiolate/Au(111) Interface

The stability of the self-assembled RS–Au–SR (R = CH2CH3)/Au(111) interface at room temperature has been investigated using scanning tunneling microscopy (STM) in conjunction with density functional theory (DFT) and MD calculations. The RS–Au–SR staple, also known as Au-adatom-dithiolate, assembles into staple rows along the [112̅] direction. STM imaging reveals that while the staple rows are able to maintain a static global structure, individual staples within the row are subjected to constant breaking and remaking of the Au–SR bond. The C2S–Au–SC2/Au(111) interface is under a dynamic equilibrium and it is far from rigid. DFT/MD calculations show that a transient RS–Au–Au–SR complex can be formed when a free Au atom is added to the RS–Au–SR staple. The relatively high reactivity of the RS–Au–SR staple at room temperature could explain the reactivity of thiolate-protected Au nanoclusters, such as their ability to participate in ligand exchange and intercluster reactions.

(Keynote) All-Atomistic Molecular Dynamics Calculation of Impact Fracture of Glassy Polymers

Impact-resistance has been one of the target properties of polymer technology from a view point of their mechanical applications. A huge number of investigations have been done for this very important property. One of the key to understand the impact resistance is to investigate the difference in microscopic behavior between brittle and ductile fractures by comparing two extrema of industrial polymers such as PMMA and PC, respectively. However, in spite of an abundance of information about macroscopic behavior of the impact fracture, little has been known about its microscopic picture. This is from difficulty in experiment for the very rapid phenomena.Molecular dynamics (MD) calculation has been one of the powerful tools for investigating microscopic behavior of molecular assemblies at an atomistic resolution. However, so far, poor performance of the supercomputers has prevented us from investigating polymers based on all-atomistic MD calculations since the systems are huge. Then, we have been obliged to depend upon coarse-grained models such as Kremer-Grest model and DPD model. But, they are not good at describing chemical character of polymers which is essential for the investigation of fracture. However, recent very rapid progress of supercomputer technology is going to enable us to investigate polymers based on all-atomistic MD calculations free from phenomenological parameters. The all-atomistic model can describe chemical details of the polymers, which is essential for the investigation of the diversity of polymers. Fracture of the polymers depends much on their chemical details such as main-chain bond breaking and side-chain motions.In particular, it is very important to include bond fracture in the simulation. Since most of the traditional MD calculations have not included bond breaking explicitly, the calculations couldn’t describe brittle fracture of polymers but always resulted in artificial ductile fracture. The bond fracture can be described using potential function such as Morse-type one. The function can be obtained by high quality quantum chemical calculations prior to the MD calculations. In the present study, brittle fracture has been investigated for PMMA including bond fracture explicitly. Systems constructed for the simulation mimicked the real system. There, experimental molecular weight distribution, density, radius of gyration, and entanglement molecular weight were reproduced well in the initial configuration prepared for the impact fracture test calculations. The calculations clearly show characteristics of the brittle fracture at a molecular level such as void formation, chain reactions of main-chain bond breaking, and small Poisson ratio.

Stability and Electronic Properties of PtPd Nanoparticles via MD and DFT Calculations

The structural as well as electronic properties of PtPd nanoparticles (NPs) were investigated by using molecular dynamics simulations and density functional theory calculations. A wide range of NPs...

Chiral recognition capabilities of melamine and cyanuric acid supramolecular structures

ABSTRACTCurrently, there are numerous papers that discuss local chiral domains in supramolecular structures of achiral molecules established using the STM method, and by using DFT calculations. However, there are no data regarding the obtainment of macroscopically chiral 2D-supramolecular structures from achiral molecules. In this study, melamine and cyanuric acid supramolecular structures were self-assembled on a graphitized carbon black surface, which had a surface structure that was identical to HOPG, and also on the surface of an inert solid support for chromatography. Chirality induction according to the Kondepudi effect was used. For the supramolecular structures, MD calculations showed the possibility of obtaining a chiral structure. To establish macroscopic chirality, we proposed the use of the difference in enantiomer adsorption on the modified adsorbents. For this, two indirect methods were used: static adsorption with a polarimetric control and gas chromatography. Both methods indicated the chiral recognition ability of the adsorbents used.

Properties of planetary silicate melts by molecular dynamics simulation

Because magmatic liquids play a fundamental role in the evolution of the terrestrial planets, a precise knowledge of their physical properties is requisite to better understand the formation and the dynamics of planetary interiors. In using an improved force field for silicates (Dufils et al., 2017), we report the results of a series of molecular dynamics simulations (MD) aiming to evaluate the equation of state (EOS), the viscosity, the electrical conductivity, and the elemental self-diffusion coefficients of various planetary melts representative of the Earth, Mars, the Moon and Mercury. The agreement between MD calculations and experimental data (when they exist) is remarkable, a finding which suggests that the MD simulations can be used on trust to extend the existing laboratory data on planetary melts (as it is proposed here for some lunar, martian and mercurian basalts) or to predict the thermo-physical properties of more exotic compositions (magma oceans, lava planets). Moreover, the MD simulations show that the evolution of the viscosity and of the electrical conductivity with the pressure depends in a complex manner on temperature and composition and that is difficult to extract general trends from these behaviors. Another advantage of the MD simulations is that the transport coefficients (viscosity, conductivity, and diffusivities) being evaluated along the same numerical experiment, one is able to test the validity of the Eyring and the Stokes-Einstein equations relating viscosity and diffusivity, as also as the Nernst-Einstein equation expressing the conductivity as function of the ionic diffusivities. It is shown that the Stokes-Einstein equation is suitable to describe planetary melts of low viscosity (≤1 Pa·s), whereas the Eyring relation leads to a better estimation at high viscosities (>100 Pa·s). Concerning the electrical conductivity, the Nernst-Einstein relation fails to reproduce the conductivity values obtained by MD simulation, a result which can be explained by the crucial role played by ion-ion correlations in silicate melts.

Ampicillin permeation across OmpF, the major outer-membrane channel in Escherichia coli

The outer cell wall of the Gram-negative bacteria is a crucial barrier for antibiotics to reach their target. Here, we show that the chemical stability of the widely used antibiotic ampicillin is a major factor in the permeation across OmpF to reach the target in the periplasm. Using planar lipid bilayers we investigated the interactions and permeation of OmpF with ampicillin, its basic pH-induced primary degradation product (penicilloic acid), and the chemically more stable benzylpenicillin. We found that the solute-induced ion current fluctuation is 10 times higher with penicilloic acid than with ampicillin. Furthermore, we also found that ampicillin can easily permeate through OmpF, at an ampicillin gradient of 10 μm and a conductance of Gamp ≅ 3.8 fS, with a flux rate of roughly 237 molecules/s of ampicillin at Vm = 10 mV. The structurally related benzylpenicillin yields a lower conductance of Gamp ≅ 2 fS, corresponding to a flux rate of ≈120 molecules/s. In contrast, the similar sized penicilloic acid was nearly unable to permeate through OmpF. MD calculations show that, besides their charge difference, the main differences between ampicillin and penicilloic acid are the shape of the molecules, and the strength and direction of the dipole vector. Our results show that OmpF can impose selective permeation on similar sized molecules based on their structure and their dipolar properties.

IR Spectra of (HCOOH)2 and (DCOOH)2: Experiment, VSCF/VCI, and Ab Initio Molecular Dynamics Calculations Using Full-Dimensional Potential and Dipole Moment Surfaces.

We report quantum VSCF/VCI and ab initio molecular dynamics (AIMD) calculations of the IR spectra of (HCOOH)2 and (DCOOH)2, using full-dimensional, ab initio potential energy and dipole moment surfaces (PES and DMS). These surfaces are fits, using permutationally invariant polynomials, to 13 475 ab initio CCSD(T)-F12a electronic energies and MP2 dipole moments. Here "AIMD" means using these ab initio potential and dipole moment surfaces in the MD calculations. The VSCF/VCI calculations use all (24) normal modes for coupling, with a four-mode representation of the potential. The quantum spectra align well with jet-cooled and room-temperature experimental spectra over the spectral range 600-3600 cm-1. Analyses of the complex O-H and C-H stretch bands are made based on the mixing of the VSCF/VCI basis functions. The comparisons of the AIMD IR spectra with both experimental and VSCF/VCI ones provide tests of the accuracy of the AIMD approach. These indicate good accuracy for simple bands but not for the complex O-H stretch band, which is upshifted from experimental and VSCF/VCI bands by roughly 300 cm-1. In addition to testing the AIMD approach, the PES, DMS, and VSCF/VCI calculations for formic acid dimer provide opportunities for testing other methods to represent high-dimensional data and other methods that perform postharmonic vibrational calculations.

Experimental and theoretical studies of the physicochemical and mechanical properties of multi-layered TiN/SiC films: Temperature effects on the nanocomposite structure

Abstract Nanoscale multilayered TiN/SiC films are of great importance in many electronic and industrial fields. The careful control over the structure of the laminates, nanocrystalline or amorphous, is crucial for their further applicability and study. However, several limitations in their fabrication have revealed important gaps in the understanding of this system. Here, we study influence of temperature on the physico-chemical and functional properties of TiN/SiC multilayers. We will show the clear increment on hardness of the samples, while the nanocomposite structure of the layers is maintained with no increment in crystal size. We will investigate the interstitial effects and rearrangements, between the TiN/SiC phases and their role in the enhanced mechanical response. Our experiments will clearly show a change in the modulation period of the samples, pointing to interfacial reactions, diffusion of ions or crystallization of new phases. Full Investigations of the film properties were carried out using several methods of analysis: XRD, XPS, FTIR, HR-TEM and SIMS Additionally, results were combined with First Principles MD computations of TiN/SiC heterostructures.

Thermodynamic Properties of l-Aspartates of Alkali and Alkali-Earth Metals in Aqueous Solutions at 298.15 and 310.15 K and Specific Cation Effects on Biomolecule Solvation

Vapor pressure osmometry was applied to the systems calcium l-aspartate ((S)-aminobutanedioic acid calcium salt) + water for varying molalities of Ca–l-Asp (mCa–l-Asp = 0.01–1.02 mol·kg−1) and guanidinium hydrochloride (methanamidine hydrochloride) + sodium L–aspartate ((S)–aminobutanedioic acid sodium salt) + water, varying the molalities of GndmCl and Na–l-Asp (mNa–l-Asp = 0.1, 0.25, 0.4, 0.57 mol·kg−1 and mGndmCl = 0.1–1.1 mol·kg−1) at T = 298.15 K and 310.15 K. From vapor pressure osmometry, activities of water, and the corresponding osmotic coefficients of the mixtures Ca–l-Asp + water and Na–l-Asp + GndmCl + water have been calculated, both being directly related to the chemical potentials of the different species and therefore to their Gibbs energy. Mean molal ion activity coefficients were obtained from experimental data fits with the Pitzer equations and the corresponding dual and triple interaction parameters were derived for the Ca–l-Asp + water binary system. β(2) Pitzer parameters different from zero are required for Ca–l-Asp in water to reproduce the osmotic coefficient decrease with increasing concentration. Mean Spherical Approximation parameters accounting for Coulomb and short range interactions that describe the calcium and magnesium aspartates and glutamates are given. The decrease in the chemical potential of the aspartates corresponds to the Hofmeister series: NaAsp > Mg(Asp)2 > CaAsp. A strong interaction between amino acid and salt due to specific dispersion interactions in amino acid salt systems containing guanidinium based salt has been revealed that is in agreement with MD and half-empirical quantum-chemical calculations.

Fast estimation of protein conformational preference at air/water interface via molecular dynamics simulations

Abstract Understanding the protein structural stability and thus its functional integrity at interface are critical for its biotechnology application development. Conventionally, it requires two extensive free energy calculations of protein in bulk and at interface to evaluate the conformational preference change during the adsorption. In this work, we derive an estimation of adsorption free energy at air/water interface for a protein in a defined conformation with the contributions of partial desolvation ΔGdesolv and surface energy ΔGa/w, which can be quickly evaluated from equilibrium MD trajectories. Via thermodynamics cycle, the free energy variation of α-helix to β-hairpin transition during the adsorption Δ Δ G w a t → i n t α → β can be obtained from the difference between the adsorption free energies of the two conformations. Applying the method, we estimate Δ Δ G w a t → i n t α → β of 6.31kJ/mol for DP5, in excellent agreement with the MD free energy data of 6.35 kJ/mol. Consistent results for four other tested proteins compared with MD free energy calculation further validate the derived adsorption model. The combination of MD simulations and thermodynamic estimations provide valuable physical insights for protein interfacial folding behaviors and serve as basis for developing prediction tools of protein conformations at interface.

Identification of Rare Lewis Oligosaccharide Conformers in Aqueous Solution Using Enhanced Sampling Molecular Dynamics.

Determining the conformations accessible to carbohydrate ligands in aqueous solution is important for understanding their biological action. In this work, we evaluate the conformational free-energy surfaces of Lewis oligosaccharides in explicit aqueous solvent using a multidimensional variant of the swarm-enhanced sampling molecular dynamics (msesMD) method; we compare with multi-microsecond unbiased MD simulations, umbrella sampling, and accelerated MD approaches. For the sialyl Lewis A tetrasaccharide, msesMD simulations in aqueous solution predict conformer landscapes in general agreement with the other biased methods and with triplicate unbiased 10 μs trajectories; these simulations find a predominance of closed conformer and a range of low-occupancy open forms. The msesMD simulations also suggest closed-to-open transitions in the tetrasaccharide are facilitated by changes in ring puckering of its GlcNAc residue away from the 4C1 form, in line with previous work. For sialyl Lewis X tetrasaccharide, msesMD simulations predict a minor population of an open form in solution corresponding to a rare lectin-bound pose observed crystallographically. Overall, from comparison with biased MD calculations, we find that triplicate 10 μs unbiased MD simulations may not be enough to fully sample glycan conformations in aqueous solution. However, the computational efficiency and intuitive approach of the msesMD method suggest potential for its application in glycomics as a tool for analysis of oligosaccharide conformation.

Host-guest interactions of non-steroidal anti-inflammatory drugs on the functionalized dendronized polymeric nanocomposite, Poly(N-tris[((cyano-ethoxy)methyl] methylacrylamide).

ABSTRACTThe use of dendronized polymers (DP), such as Poly(N-tris[((cyano-ethoxy)methyl]methylacrylamide) (PATCN), as carriers models of different non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (IBU), Ketoprofen (KTP), and Naproxen (NPX), is reported. DSC and TGA measurements demonstrate strong interactions between dendronized polymeric nanocomposites and these drugs. FT-IR, UV-Vis, and AFM measurements confirm that the interactions in the blend give rise to a compatible new material in only one phase. Using the Fukui Theory (FT), the interaction appears to take place through the main amide and its neighborhood. Thus, the drugs' and polymer's functional groups contribute to the strength of the interaction. The functional groups and the sizes of the drugs are the driving force for the interaction with the DP. Finally, MD calculations are carried out through DFT methods to investigate the behavior of the dendronized polymer, showing that different chain behaviors depend on the placement of the lateral chains.

Adsorption behavior and mechanism of acidic blue 25 dye onto cucurbit[8]uril: A spectral and DFT study

The acidic blue 25 (AB25) dye was efficiently adsorbed by CB [8]; the saturated adsorption capacity (qexp) reached 434.8mg/g and was far higher than those of previous reported adsorbents. The Langmuir and Freundich isotherms were used to fit the equilibrium data, and the results showed that the Freundlich isotherm seemed to agree better with the AB25 adsorption. The adsorption kinetics followed the pseudo-second-order model. Calculated thermodynamic parameters showed that the adsorption of AB25 onto CB [8] was a spontaneous and enthalpy-driven process. The adsorption mechanism was explored by N2 adsorption-desorption, TG, FT-IR, UV–vis as well as MD simulation and DFT calculations. TG analysis revealed that a new inclusion complex was produced, and FT-IR,UV–vis spectrum and DFT calculations verify its structure. In this inclusion complex, the AB25 dye molecule inserted into cavities of CB [8] from portal, and the sulfonate and phenyl groups stayed in the hydrophobic cavity. TDDFT calculations indicated that all excitation arisen from π→π* transition.