Molecular dynamics study of dispersion and fluidity of porous liquids with different pore sizes

Study on Thermophysical Properties and Phase Change Regulation Mechanism of Optically-Controlled Phase Change Materials: Synthesis, Crystal Structure and Molecular Dynamics

Optically-controlled phase change materials, which are prepared by introducing molecular photoswitches into traditional phase change materials (PCMs), can convert and store solar energy into photochemical enthalpy and phase change enthalpy. However, the thermophysical properties of optically controlled PCMs, which are crucial in the practical, are rarely paid attention to. 4-(phenyldiazenyl)phenyl decanoate (Azo-A-10) is experimentally prepared as an optically-controlled PCMs, whose energy storage density is 210.0 kJ·kg-1, and the trans single crystal structure is obtained. The density, phase transition temperature, thermal conductivity, and other parameters in trans state are measured experimentally. Furthermore, a microscopic model of Azo-A-10 is established, and the thermophysical properties are analyzed based on molecular dynamics. The results show that the microstructure parameter (order parameters) and thermophysical properties (density, radial distribution function, self-diffusion coefficient, phase change temperature, and thermal conductivity) of partially or completely isomerized Azo-A-10, which are challenging to observe in experiments, can be predicted by molecular dynamics simulation. The optically-controlled phase change mechanism can be clarified according to the differences in microstructure. The optically-controlled switchability of thermophysical properties of an optically-controlled PCM is analyzed. This study provides ideas for the improvement, development, and application of optically-controlled PCMs in the future.

Porous liquids: a novel porous medium for efficient carbon dioxide capture

Porous liquids (PLs) are the combination of porous solid material and flowing liquid, which provides alternative options to solve difficulties in the development of porous solids. With the booming development of PLs since 2015, plenty of syntheses and applications have been reported with a specific focus on gas adsorption. Given the lack of a comprehensive review, this paper reviews the application of PLs in CO2 capture. To start with, ground-breaking case studies are reviewed to help understand the progress of PLs research. Then, as a major part of this paper, studies of PLs for CO2 capture are reviewed separately. Moreover, five basic properties of porous liquids, including stability, viscosity, selectivity, porosity, capacity, and the influencing factors are systemically reviewed respectively. Furthermore, gas storage and release mechanisms in PLs are briefly outlined, and potential processing methods of PLs used for CO2 capture are discussed.

Practical considerations in the design and use of porous liquids

The possibility of creating well-controlled empty space within liquids is conceptually intriguing, and from an application perspective, full of potential. Since the concept of porous liquids (PLs) arose several years ago, research efforts in this field have intensified. This review highlights the design, synthesis, and applicability of PLs through a thorough examination of the current state-of-the-art. Following a detailed examination of the fundamentals of PLs, we examine the different synthetic approaches proposed to date, discuss the nature of PLs, and their pathway from the laboratory to practical application. Finally, possible challenges and opportunities are outlined.

Porous liquids - the future is looking emptier

The development of microporosity in the liquid state is leading to an inherent change in the way we approach applications of functional porosity, potentially allowing access to new processes by exploiting the fluidity of these new materials. By engineering permanent porosity into a liquid, over the transient intermolecular porosity in all liquids, it is possible to design and form a porous liquid. Since the concept was proposed in 2007, and the first examples realised in 2015, the field has seen rapid advances among the types and numbers of porous liquids developed, our understanding of the structure and properties, as well as improvements in gas uptake and molecular separations. However, despite these recent advances, the field is still young, and with only a few applications reported to date, the potential that porous liquids have to transform the field of microporous materials remains largely untapped. In this review, we will explore the theory and conception of porous liquids and cover major advances in the area, key experimental characterisation techniques and computational approaches that have been employed to understand these systems, and summarise the investigated applications of porous liquids that have been presented to date. We also outline an emerging discovery workflow with recommendations for the characterisation required at each stage to both confirm permanent porosity and fully understand the physical properties of the porous liquid.

Transforming Porous Silica Nanoparticles into Porous Liquids with Different Canopy Structures for CO2 Capture

Porous liquids (PLs) have both liquid fluidity and solid porosity, thereby offering a variety of applications, such as gas sorption and separation, homogeneous catalysis, energy storage, and so forth. In this research, canopies with varying structures were utilized to modify porous silica nanoparticles to develop Type I PLs. According to experimental results, the molecular weight of canopies should be high enough to maintain the porous materials in the liquid state at room temperature. Characterization results revealed that PL_1_M2070 and PL_1_AC1815 displayed low viscosity and good fluidity. Both low temperature and high pressure positively influenced CO₂ capacity. The cavity occupancy resulted in poorer sorption capacity of PLs with branched canopies in comparison with that with linear canopies. Furthermore, the sorption capacity of PL_1_M2070 was 90.5% of the original CO₂ sorption capacity after 10 sorption/desorption cycles, indicating excellent recyclability.