Search Results (73)

In this study, β-cyclodextrin (β-CD) functionalized graphene quantum dots (GQDs) was employed to augment the array of chiral recognition sites, thereby enhancing the affinity of GQDs/β-CD composite for imprinting molecules and realizing heightened chiral selectivity. The incorporation of GQDs/β-CD into the synthesis of molecularly imprinted polymers (MIPs), synergizing with the host-guest inclusion properties of β-CD and the abundant carboxyl groups of GQDs, enhanced the chiral recognition capacity of MIPs materials. Consequently, a novel MIPs/(GQDs/β-CD) sensor with chiral recognition capabilities tailored for D-carnitine was successfully fabricated. The binding mechanism between GQDs/β-CD and D-carnitine was elucidated via Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy. The variation in the response signal (ΔI) of the probe molecule exhibited a linear correlation with the logarithm of D-carnitine concentration (lgC) in the range of 1.0 × 10⁻¹² mol/L to 1.0 × 10⁻⁹ mol/L, and the detection limit (3δ/S) was calculated as 2.35 × 10⁻¹³ mol/L. These results underscore a 7.15-fold enhancement in the selectivity of MIPs/(GQDs/β-CD) sensor for D-carnitine recognition. Moreover, the sensor presented commendable efficacy in real-world scenarios, yielding recovery rates ranging from 98.5% to 103.0% during the determination of D-carnitine content in real samples. Full article

Pterostilbene (PTS) has multiple benefits, but poor water solubility and bioavailability limit its application. PTS/β-CD inclusion complexes were synthesized through the phase solubility method to enhance their water solubility. The inclusion complexes were characterized through Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, nuclear magnetic resonance, and molecular docking techniques. The results demonstrated that PTS and β-CD successfully created inclusion complexes with a host–guest ratio of 1:1 and a stability constant of 166.7 M⁻¹. To further investigate its prebiotic function, simulated digestion experiments revealed that β-CD exhibited resistance to digestion, allowing it to reach the colon intact. During gastrointestinal digestion, PTS in the PTS/β-CD inclusion complexes was gradually released. Following digestion, the in vitro fermentation of healthy human feces further confirmed the probiotic properties. Compared to the β-CD and fructooligosaccharide (FOS) groups, the PTS/β-CD group significantly increased the production of acetic acid, butyric acid, and lactic acid, respectively. Additionally, beneficial bacteria, such as Bifidobacterium and Lactobacillus, proliferated in the PTS/β-CD group, while the relative abundance of potential pathogenic bacteria, such as Lactococcus, Streptococcus, and Klebsiella, was significantly reduced. Compared to the blank group, propionic acid and butyric acid concentrations in the β-CD group were significantly higher. The abundance of Lactobacillus and other key bacterial species in the β-CD group increased, while the relative abundance of Klebsiella and other pathogens decreased significantly. In conclusion, PTS/β-CD inclusion complexes altered the composition of intestinal flora, promoting the proliferation of beneficial bacteria and inhibiting the growth of harmful bacteria, thereby demonstrating dual probiotic functionality. Full article

A novel β-cyclodextrin–graphene oxide (β-CD/GO) composite adsorbent was synthesized via a hydrothermal method. Removal efficiency and mechanisms of typical pharmaceutical and personal care products (PPCPs) by the β-CD/GO composite were investigated in aqueous solutions. The results demonstrated that the β-CD/GO composite was successfully formed through cross-linking between β-CD and GO nanosheets, exhibiting enriched hydroxyl groups, a porous layered structure, and good thermal stability. The adsorption of cimetidine (CTD), sulfamethazine (SMZ), and diclofenac (DCF) onto the β-CD/GO composite was well described by pseudo-first-order and pseudo-second-order kinetic models, and Langmuir isotherm. The maximum adsorption capacities of CTD, SMZ, and DCF onto the β-CD/GO composite were 58.86, 35.62, and 29.11 mg g⁻¹ at 298 K, respectively. The adsorption process was rapid and reached equilibrium after 6 h. The adsorption followed a monolayer mechanism and was an exothermic process. The adsorption capacity decreased with increasing pH values and ion concentrations. The β-CD/GO composite exhibited maximum adsorption capacities of 17.69, 16.96, and 16.23 mg g⁻¹ for CTD, SMZ, and DCF, respectively, under a pH of 4 with a dosage of 1.0 g/L at 298 K for 6 h. Due to the combined impacts of electrostatic interaction, hydrogen bonding, and host–guest interaction, the adsorption of PPCPs onto β-CD/GO composite was fast and efficient. β-CD/GO composite exhibited superior adsorption efficacy and structural stability, which highlighted its promising application in the elimination of micropollutants from aqueous solutions. Full article

A simple and non-chemical binding nanofiber (β-CD/PA) adsorbent was obtained by electrospinning a mixture of β-cyclodextrin (β-CD) and polyacrylate (PA). The cationic dyes in wastewater were removed by the host–guest inclusion complex of the β-cyclodextrin and the electrostatic interaction between the polyacrylate and the dyes groups. The influence of the content of β-cyclodextrin on the surface morphology and adsorption capacity of the nanofiber membrane was discussed, and the optimized adsorption capacity of nanofiber adsorption material was determined. The adsorption capacity of nanofiber adsorbents for basic red 9, basic red 14, basic red 46, basic blue 9, basic yellow 19 and basic yellow 28 was 86.71 mg/g, 21.513 mg/g, 18.926 mg/g, 44.525 mg/g, 116.516 mg/g and 155.206 mg/g, respectively. The effects of different initial concentrations and pH values on the adsorption properties of adsorbent materials were studied. The kinetic analysis showed that the adsorption process of nanofibers for cationic dyes was more in line with the pseudo-second-order kinetic adsorption model. Moreover, nanofiber adsorbent could be easily separated from the dye solution and showed high recycling efficiency. These results indicated that the β-cyclodextrin/polyacrylate composite nanofibers are expected to be recyclable adsorbents in dye wastewater treatment. Full article

The identity of community residents is the basis for passing on the GIAHS (globally important agricultural heritage system) and promoting the sustainable development of heritage sites. However, there is a lack of discussion in the existent literature on its composition and effective mechanisms. Based on the theory of the ABC (Affect–Behavior–Cognition) model, we collected 482 questionnaires from residents of tea communities of the GIAHS. We construct a model of multiple effects of identity on willingness to co-create values based on the perspective of host–guest interaction. The results show that identity has both social identity and self-identity dimensions. It has a valuable effect on the process of host–guest interaction. It stimulates residents’ willingness to co-create value for the GIAHS through the chain-mediating effect of welcoming nature and emotional closeness. The study results reveal the theoretical mechanisms by which the identity of residents influences the multiple behaviors of guests. It also provides an interactive perspective for the study of the participation of the community in the GIAHS. At the same time, it promotes the local practice of value mining and development research in the GIAHS. In addition, it expands the research framework of value co-creation in heritage tourism. Full article

A host–guest-based fluorescent composite with a large Stokes shift was synthesized by intercalating 2,2′-(thiophene-2,5-diyl)bis(benzo[d]oxazol-6-amine) (BBTA) into the nanochannels of zeolite L (ZL) and sealing the pores with (3-aminopropyl)triethoxysilane (APTES). To confirm the orientation of the amino groups in BBTA, a single crystal of 2,5-bis(6-nitrobenzo[d]oxazol-2-yl)thiophene (BBTN) was grown and examined by X-ray crystallography. The evidence of successful intercalation of BBTA into the nanochannels of ZL was provided by fluorescence spectrometry, gas sorption and fluorescence microscopy. BBTA showed a Stokes shift of 6641 cm⁻¹ (157 nm) in ethanol and 4611 cm⁻¹ (93 nm) in toluene. The BBTA-ZL composite (BBTA-ZL-s) showed a Stokes shift of 5677 cm⁻¹ (123 nm) in toluene, and 5450 cm⁻¹ (124 nm) in ethanol. In addition, the degree of loading was determined and stability against leaching was confirmed. We report the synthesis of this novel composite dye material with potential applications where free dyes are not applicable and which retains a large Stokes shift, independent of its chemical environment. Full article

Wood, a renewable and abundant biomass resource, holds substantial promise as an encapsulation matrix for thermal energy storage (TES) applications involving phase change materials (PCMs). However, practical implementations often reveal a disparity between observed and theoretical phase change enthalpy values of wood-derived composite PCMs (CPCMs). This study systematically explores the confinement behavior of organic PCMs encapsulated in a delignified balsa wood matrix with morphology genetic nanostructure, characterized by a specific surface area of 25.4 ± 1.1 m²/g and nanoscale pores averaging 2.2 nm. Detailed thermal performance evaluations uncover distinct phase change behaviors among various organic PCMs, influenced by the unique characteristics of functional groups and carbon chain lengths. The encapsulation mechanism is primarily dictated by host–guest interactions, which modulate PCM molecular mobility through hydrogen bonding and spatial constraints imposed by the hierarchical pore structure of the wood. Notably, results demonstrate a progressive enhancement of nanoconfinement effects, evidencing a transition from octadecane to stearic acid, further supported by density functional theory (DFT) calculations. This research significantly advances the understanding of nanoconfinement mechanisms in wood-derived matrices, paving the way for the development of high-performance, shape-stabilized composite PCMs that are essential for sustainable thermal energy storage solutions. Full article

The sustainable development of tourism is a critical issue, and immersive tourism has emerged as a key market trend that significantly contributes to this goal. Experiencescape, a vital component of immersive tourism, plays a crucial role in shaping tourists’ experience and promoting sustainability within the tourism industry. Taking Chang’an Twelve Hours Theme Block as the research object, this paper investigates the composition and impact of immersive tourism experiencescape by utilizing grounded theory and hierarchical regression analysis on data derived from online reviews and tourist surveys. The findings reveal that immersive tourism experiencescape is divided into two main categories: physical and interpersonal. The physical experiencescape consists of three dimensions: functional facilities, thematic atmosphere, and basic environment. The interpersonal experiencescape, on the other hand, includes tourism performances, host-guest interaction, and personal service. The study demonstrates that immersive tourism experiencescape exerts a significant positive influence on tourists’ behavioral intentions, with emotional experience serving as a partial mediator in this relationship. These insights offer valuable theoretical and practical implications. They provide a perspective for enhancing the sustainability of tourism by improving the quality of immersive experiences. Full article

Circularly polarized luminescence (CPL) materials have been widely used in the fields of bioimaging, optoelectronic devices, and optical communications. The supramolecular interaction, involving harnessing non-covalent interactions between host and guest molecules to control their arrangements and assemblies, represents an advanced approach for facilitating the development of CPL materials and finely constructing and tuning the desired CPL properties. Cyclodextrins (CDs) are cyclic natural polysaccharides, which have also been ubiquitous in various fields such as molecular recognition, drug encapsulation, and catalyst separation. By adjusting the interactions between CDs and guest molecules precisely, composite materials with CPL properties can be facilely generated. This review aims to outline the design strategies and performance of CD-based CPL materials comprehensively and provides a detailed illustration of the interactions between host and guest molecules. Full article

Left-handed materials are known to exhibit exotic properties in controlling electromagnetic fields, with direct applications in negative reflection and refraction, conformal optical mapping, and electromagnetic cloaking. While typical left-handed materials are constructed periodic metal-dielectric structures, the same effect can be obtained in composite guest–host systems with no periodicity or structural order. Such systems are typically described by the effective-medium approach, in which the components of the electric permittivity tensor are determined as a function of individual material properties and doping concentration. In this paper, we extend the discussion on the mixing rules to include left-handed composite systems and highlight the exotic properties arising from the effective-medium approach in this framework in terms of effective values and dispersion properties. Full article

This study explored the design of an innovative stereoselective S-(-)-limonene sensor according to the molecular imprinting polymer (MIP) strategy using UV light to generate in situ polymer cross-linking. A conductive composite nanofibrous fabric of polyvinylpyrrolidone (PVP), polyacrylic acid (PAA) and carbon nanotubes (MWCNTs) was deposited on purpose in a single step by electrospinning onto interdigital microelectrodes. The nanostructured layer was investigated by microscopy (SEM, TEM, AFM) and infrared transmission measurements (FTIR). The resulting sensing features (carried out in environmental air) seemed to be mainly dependent on the peculiarity of the nanostructure and the phenomena occurring at the interfaces between the cross-linked PVP–PAA/cavity shape and MWCNTs. Furthermore, the specificity of the host–guest interaction was proven by the sensitivity, selectivity and stereoselectivity of the sensor when exposed to similar monoterpenes ((±)-α-pinene and (±)-linalool) and the enantiomer of limonene (R(+)), respectively. Full article

Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb³⁺/Eu³⁺-doped CaZrO₃ in detail. The intrinsic purple-blue luminescence from host CaZrO₃ and the introduced green/red luminescence from guest dopants Tb³⁺/Eu³⁺ were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb³⁺/Eu³⁺-doped CaZrO₃. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption. Full article

In this study, we have developed innovative polymer nanocomposites by integrating magnesium-aluminum layered double hydroxide (LDH)-based nanocarriers modified with functional molecules into a fully biobased poly(lactic acid)/poly(butylene succinate-co-adipate) (PLA/PBSA) matrix. These LDH-based hybrid host-guest systems contain bioactive compounds like rosmarinic acid, ferulic acid, and glycyrrhetinic acid, known for their antioxidant, antimicrobial, and anti-inflammatory properties. The bioactive molecules can be gradually released from the nanocarriers over time, allowing for sustained and controlled delivery in various applications, such as active packaging or cosmetics. The morphological analysis of the polymer composites, prepared using a discontinuous mechanical mixer, revealed the presence of macroaggregates and nano-lamellae at the polymer interface. This resulted in an enhanced water vapor permeability compared to the original blend. Furthermore, the migration kinetics of active molecules from the thin films confirmed a controlled release mechanism based on their immobilization within the lamellar system. Scaling-up experiments evaluated the materials’ morphology and mechanical and thermal properties. Remarkably, stretching deformation and a higher shear rate during the mixing process enhanced the dispersion and distribution of the nanocarriers, as confirmed by the favorable mechanical properties of the materials. Full article

Considering the ever-increasing interests in natural gas hydrates, a better and more precise knowledge of how host sediments interact with hydrates and affect the formation process is crucial. Yet less is reported for the effects of sediments on structure II hydrate formation with complex guest compositions. In this study, experimental simulations were performed based on the natural reservoir in Qilian Mountain permafrost in China (QMP) due to its unique properties. Mixed gas hydrates containing CH₄, C₂H₆, C₃H₈, and CO₂ were synthesized with the presence of natural sediments from QMP, with quartz sands, and without sediments under identical p–T conditions. The promoting effects of sediments regardless of the grain size and species were confirmed on hydrate formation kinetics. The ice-to-hydrate conversion rate with quartz sand and natural QMP sediments increased by 23.5% and 32.7%, respectively. The compositions of the initial hydrate phase varied, but the difference became smaller in the resulting hydrate phases, having reached a steady state. Beside the structure II hydrate phase, another coexisting solid phase, neither ice nor structure I hydrate, was observed in the system with QMP sediments, which was inferred as an amorphous hydrate phase. These findings are essential to understand the mixed gas hydrates in QMP and may shed light on other natural hydrate reservoirs with complex gas compositions. Full article

This content introduces a novel Ultraviolet (UV)-shielding material, Zn₂Al-MADS-LDH (MADS-LDH), which was synthesized through co-precipitation method to insert sodium dodecyl diphenyl ether disulfonate (MADS) into the interlayer of Zn₂Al-LDH layered double hydroxide (LDH), to improve the photoaging resistance of polyvinyl chloride (PVC). The characterization results indicated that MADS-LDH had a host-guest interaction between the LDH host layer and MADS guest anion, and it exhibited superior UV absorption capabilities than Zn₂Al-CO₃-LDH (CO₃-LDH) and a broader absorption spectrum compared to MADS. A series of LDHs/PVC film composite materials containing LDHs nanosheets were prepared by incorporating the prepared LDHs into a PVC matrix via a solvent casting method. As expected, the MADS-LDH/PVC film composite materials exhibited enhanced photoaging resistance. The results of photoaging tests indicated that MADS-LDH inhibits the rate of carbonyl generation during photoaging of MADS-LDH/PVC film composite materials, resulting in a decrease in the carbonyl index (ΔCl) and relative degradation rate (RDR) compared to pristine PVC film and CO₃-LDH/PVC film composite materials. Furthermore, the study evaluated the influence of different UV light wavelength ranges, such as UVB (280~315 nm), UVC (200~280 nm), and UV (200~400 nm), on the aging performance of PVC film and LDHs/PVC film composite materials. The results demonstrated that UV had the highest aging effect on PVC composite films, followed by UVC and UVB. Therefore, the MADS-LDH is a highly efficient and promising UV-shielding material with excellent potential for wide applications in the field of PVC. Full article