Nowadays, the addition of nanoparticles to polymer solutions would be of interest; however, the feasible property of nanoparticles and their impact on oil recovery has not been investigated in more detail. This study investigates the rheology and capillary forces (interfacial tension and contact angle) of nanoparticles in the polymer performances during oil recovery processes. Thereby, a sequential injection of water, polymer, and nanoparticles; Nanosilica (SiO2) and nano-aluminium oxide (Al2O3) was performed to measure the oil recovery factor. Retention decrease, capillary forces reduction, and polymer viscoelastic behavior increase have caused improved oil recovery due to the feasible mobility ratio of polymer–nanoparticle in fluid loss. The oil recovery factor for polymer flooding, polymer–Al2O3, and polymer–SiO2 is 58%, 63%, and 67%, respectively. Thereby, polymer–SiO2 flooding would provide better oil recovery than other scenarios that reduce the capillary force due to the structural disjoining pressure. According to the relative permeability curves, residual oil saturation (Sor) and water relative permeability (Krw) are 29% and 0.3%, respectively, for polymer solution; however, for the polymer–nanoparticle solution, Sor and Krw are 12% and 0.005%, respectively. Polymer treatment caused a dramatic decrease, rather than the water treatment effect on the contact angle. The minimum contact angle for water and polymer treatment are about 21 and 29, respectively. The contact angle decrease for polymer treatment in the presence of nanoparticles related to the surface hydrophilicity increase. Therefore, after 2000 mg L−1 of SiO2 concentration, there are no significant changes in contact angle.

The UV-Vis absorption and fluorescence spectra of proanthocyanidins at different pH values were studied, and the change of absorption peak position was analyzed. The intermediate stable states of proanthocyanidins in different pH conditions, the electron transition modes and emission spectra of these steady states were analyzed. Eight parts of proanthocyanidins, each with mass of 1.00 mg, were added to acetic acid buffer solution with different pH in turn. The absorption of samples at the same pH concentration was measured by UV-visible spectrophotometer and fluorescence spectrophotometer, spectrogram analysis was carried out. The absorption peak wavelength of proanthocyanidins did not change obviously in acid condition, the quantum yield of proanthocyanidins was low in different pH solutions, and the excited molecules returned to the ground state mainly by non-radiative transition. Under the same temperature conditions, the stability of proanthocyanidins decreased with the increase of pH, and the color of the solution ranged from orange to red. The charge distribution of hydroxyl groups analyzed the ability of combining free radicals at different sites of proanthocyanidins with hydroxyl groups, which suggested that proanthocyanidins may have better antioxidant activity.

At present, the research on fluorescent molecular probe has become a hot topic in the field of environmental science, chemical materials, medicine, and other fields. Therefore, the detection of industrial mercury-containing wastewater (Hg2+) is of great significance. In this article, the fluorescent probe is used to detect mercury ions, and when compared with the traditional detection method, the fluorescent probe has the advantage of operation such as the effect of simplicity is evident. The experiments first synthesized rhodamine B derivatives and then the synthesized rhodamine B derivative fluorescent molecular probes were constructed and used to detect the mercury ions in water sample and oil paints. It was demonstrated that rhodamine B-derived probes have been constructed by UV and fluorescence spectroscopy. The different metal ions and rhodamine B-derived fluorescent molecular probes were compounded, resulting in the appearance of fluorescence peak centered at 583 nm only after the addition of metallic mercury ions with almost no response from other ions. The mercury ion rhodamine B derivative is more responsive to metallic mercury ions.

Recent studies have shown that the composite of semiconductor photocatalytic materials and g-C3N4 can effectively inhibit photocatalytic carrier recombination and enhance the adsorption performance of the composite photocatalytic materials, so that the composite photocatalyst has stronger photocatalytic activity. In this paper, three kinds of graphitic carbon nitride photocatalyst g-C3N4 with different morphologies were prepared using the same precursor system by the chemical cracking method. After characterization and application, the sample with the most significant photocatalytic activity was selected and the g-C3N4/BiVO4 heterostructure was synthesized by the simple solvent evaporation method, then the photocatalytic experiment was carried out. The results show that, when the content of BiVO4 in the composite sample is 1%, the photocatalytic activity of RhB was the highest, and the degradation rate could reach 90.4%. The kinetic results showed that the degradation of RhB was consistent with the quasi-primary degradation kinetic model. The results of the photocatalytic cycle experiment show that the photocatalytic performance remains unchanged and stable after four photocatalytic cycles. The existence of a g-C3N4/BiVO4 binary heterojunction was confirmed by UV/Visible diffuse reflection (UV-DRS) and photoluminescence (PL) experiments. Owing to the Z-type charge process between BiVO4 and g-C3N4, efficient carrier separation was achieved, thus enhancing the photocatalytic capacity. This work provides a new idea for the study of heterojunction photocatalytic materials based on g-C3N4.

A new recyclable basic ionic liquid was introduced as an efficient catalyst for aldol condensation and transesterification reactions under environmentally friendly conditions. The catalyst was prepared based on methyl imidazolium moieties bearing hydroxide counter anions via the Hofmann elimination on a 1,3,5‐triazine framework. The ionic liquid with two functionalities including anion stabilizer and high basicity, was used as an efficient catalyst for aldol condensation as well as transesterification reaction of a variety of alkyl benzoates. All reactions were performed in the absence of any external reagent, co‐catalyst, or solvent, in line with environmental protection. The kinetics isotope effect (KIE) was conducted for the transesterification reaction to elucidate the mechanism and rate determining step (RDS). It worth noted that, the homogeneous catalyst could be recycled from the reaction mixture and reused for several consecutive runs with insignificant drop of basicity and conversion.