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The organic 3-hydroxy-4-methoxybenzaldehyde single crystal has been grown by the slow evaporation technique. Single crystal X-ray diffraction (XRD) study shows that the grown crystal belongs to a monoclinic crystal system with centrosymmetric space group P21/c. The spectral analysis of 3-hydroxy-4-methoxybenzaldehyde calculations was performed with the help of DFT at the B3LYP/6-311 + G(d,p) level of theory. The experimental results of FTIR and FT-Raman were compared with the computational results. Detailed interpretations of the vibrational spectra were carried out with the aid of vibrational energy distribution analysis using potential energy distribution (PED) analysis and vibrational wavenumber scaled by the WLS (Wavenumber Linear Scaling) method. The natural bond orbital (NBO) analysis was carried out to identify intramolecular hydrogen bonding. The optical properties of the grown crystal were analyzed by UV–Visible studies. Photoluminescence studies show that the high-intensity peak observed around 410 nm. The laser damage threshold value of the grown crystal has been determined using an Nd:YAG laser operating at 1064 nm. The HOMO (Highest Occupied Molecular Orbital) – LUMO (Lowest Unoccupied Molecular Orbital) was used to identify the energy gap. Hirshfeld Surface (HS) analysis was used to determine the intermolecular interactions. The thermal properties of the grown crystal were performed by Thermogravimetric (TG) and Differential thermal analyses (DTA). The kinetic and thermodynamic parameters were calculated. The surface morphology of the grown crystal was studied by using Scanning Electron Microscopy (SEM) analysis. The antibacterial and antifungal studies were analyzed.

A clear understanding of pore structure of tight oil reservoirs is essential for reservoir evaluation and enhanced oil recovery. This paper presents a multiscale characterization method using a combination of pressure-controlled porosimetry (PCP), micro-computed tomography (micro-CT), and scanning electron microscopy (SEM). Four tight sandstone samples from Chang 7 Formation in the Ordos Basin were collected for petrophysical characterization. Pore-throat size distributions (PTSDs) for these samples were measured via PCP. A high-resolution micro-CT scan (1 μm/pixel) was used to acquire 3D volumetric images of small core plugs to evaluate pore connectivity of these samples. Additionally, high-resolution digital images were obtained through SEM to identify different pore types. SEM analysis shows that pores in tight sandstones could be classified into four types, i.e., residual interparticle pores, grain dissolution pores, clay pores, and micro-fractures. Residual interparticle pores are often coated by fibrous illite and chlorite. Grain dissolution pores are mainly deduced from the dissolution of grain minerals, among them the feldspar dissolution pore is the primary type. According to the PCP experiments, these samples exhibit multiscale pore structures with a wide range of PTSD from 9.2 nm to 500 μm dominated by nanopores. Average mercury intrusion saturation and permeability contribution value of the dominating nanopores are 63.61% and 80%, respectively. Given the unresolved nanopores, CT images were segmented into three phases, including pore space, grain phase, and clay minerals. The results of connectivity analysis demonstrate that macroscopic pores are mostly connected by clay phases, implying that nanopores provide the critical flow paths. This novel multiscale characterization approach provides us a better understanding of complex pore structures of tight sandstones. [ABSTRACT FROM AUTHOR]