The Application of Ferric Chloride-Lignin Sulfonate as Shale Inhibitor in Water-Based Drilling Fluid.

A series of ferric chloride-lignin sulfonate (FCLS) was prepared from ferric chloride and lignin sulfonate to be used as shale inhibitor. The swelling rate of clay with FCLS-2 ( = 0.3%) decreased to 41.

Characterization of ultraviolet-modified biochar from different feedstocks for enhanced removal of hexavalent chromium from water.

Biochars produced from different feedstocks via pyrolytic carbonization and ultraviolet (UV) modification were used as alternative adsorbents for aqueous hexavalent chromium (Cr(VI)) remediation. Structural and morphological analysis showed that UV irradiation increased the surface area of biochar and added a large amount of oxygen-containing functional groups on the biochar's surface, resulting in about 2-5 times increase of Cr(VI) removing capacity (14.39-20.

The enhanced effect of oxalic acid on the electroreduction of Cr(VI) via formation of intermediate Cr(VI)-oxalate complex.

In this study, the enhanced effect of oxalic acid (Ox) on Cr(VI) electroreduction was evaluated. It was found that for Cr(VI)-contaminated solution ([Cr(VI)] = 1.0 mM, pH = 3.

Preparation and application of melamine cross-linked poly ammonium as shale inhibitor.

In this paper, a series of poly ammonium shale inhibitors were prepared from diethylamine, epichlorohydrin, and melamine (DEM) and their inhibition to shale were evaluated by bentonite linear expansion test, anti-swelling experiments, and mud ball experiments. Additionally, other properties of drilling fluid treated by poly ammonium were evaluated. Anti-swelling results showed that anti-swelling rate of DEM-8 reaches up to 97.

A green chemometrics-assisted fluorimetric detection method for the direct and simultaneous determination of six polycyclic aromatic hydrocarbons in oil-field wastewaters.

Oil-field wastewaters contain high level of polycyclic aromatic hydrocarbons (PAHs), which have to be analyzed to assess the environmental effects before discharge. In this work, a green fluorimetric detection method that combines excitation-emission matrix (EEM) fluorescence with parallel factor analysis (PARAFAC) algorithm was firstly developed to achieve the direct and simultaneous determination of six U.S.

Preparation and Application of a New Crosslinked Polyammonium as a Shale Inhibitor.

Background: Despite the fact that a number of traditional shale inhibitors have been utilized widely in drilling operations, the same additive may be unfavorable for different drilling due to environmental protection requirements which limit scales of use. Hence, a series of polyammonium compounds was prepared from dimethylamine, epichlorohydrin, and melamine (DEM).

Methods: To concentrate our efforts, we used both standard and extra methods to investigate the inhibitive properties of a melamine crosslinking agent using mud balls immersion tests, linear expansion measurements, laser particle distribution measurements, thermogravimetric analysis, and scanning electron microscopy.

Aggregation Behavior of Dissolved Black Carbon: Implications for Vertical Mass Flux and Fractionation in Aquatic Systems.

The fluvial export of dissolved black carbon (DBC) is a major land-ocean flux in the global black carbon cycle, affecting the size of refractory carbon pool in the oceans. The aggregation behavior of DBC is a significant determinant of its transport and vertical mass flux. In this study, the aggregation kinetics and interaction energy of DBC leached from biochar were investigated.

Cation-Pi Interaction: A Key Force for Sorption of Fluoroquinolone Antibiotics on Pyrogenic Carbonaceous Materials.

Cation-pi attraction is a major force that determines macromolecular structures and drug-receptor interactions. However, the role of the cation-pi interaction in sorption of fluoroquinolone antibiotics by pyrogenic carbonaceous materials (PCMs) has not been addressed. We studied sorption of ciprofloxacin (CIP) on graphite to quantify the contribution of the cation-pi interaction.

DNA Three-Way Junction for Differentiation of Single-Nucleotide Polymorphisms with Fluorescent Copper Nanoparticles.

A label- and enzyme-free fluorescent sensor for the detection of single-nucleotide polymorphisms (SNPs) at room temperature is proposed, using new copper nanoparticles (CuNPs) as fluorescent reporters. The CuNPs were constructed by using a DNA three-way junction (3WJ) template. In this assay, two complementary adenine/thymine-rich probes can hybridize with the wild-type target simultaneously to construct a 3WJ structure, serving as an efficient scaffold for the generation of CuNPs.

Silica-coated triangular gold nanoprisms as distance-dependent plasmon-enhanced fluorescence-based probes for biochemical applications.

Plasmon-enhanced fluorescence (PEF)-based anisotropic nanostructures are considered extremely promising tools for improving the inherent problems of traditional fluorophores and for detecting important biomolecules with high sensitivity. Herein, a novel triangular gold nanoprism (AuNPR)-based fluorescence probe, AuNPR@SiO@12,17-tetramethyl-3-dihydro-(2s-trans)-thyl-7(Ce6), was developed for PEF by virtue of multiple "hot spots" of AuNPRs. Fluorescence enhancement of fluorophores can be realized owing to the larger and stronger electromagnetic fields located at the sharp tips of AuNPRs than those on spherical particles and nanorods.

Near-Infrared-Fluorescent Probes for Bioapplications Based on Silica-Coated Gold Nanobipyramids with Distance-Dependent Plasmon-Enhanced Fluorescence.

Optical antennas with anisotropic metal nanostructures are widely used in the field of fluorescence enhancement based on localized surface plasmons (LSPs). They overcome the intrinsic defects of low brightness of near-infrared (NIR) dyes and can be used to develop sensitive NIR sensors for bioapplications. Here, we demonstrate a novel NIR plasmon-enhanced fluorescence (PEF) system consisting of elongated gold nanobipyramids (Au NBPs) antennas, silica, and NIR dyes.