Cationic polyacrylamide (CPAM) solid particle is one of the most commonly used organic polymer flocculants in oilfield wastewater treatment, but it poses some problems, such as a slow dissolution rate and an easy formation into a "fish-eye" in the process of diluting into aqueous solution. However, the current liquid CPAM products also have some problems, such as low effective content, poor storage stability, degradation in a short time, and high preparation costs. In this paper, a CPAM suspension was successfully prepared with 50.
View Article and Find Full Text PDFFiltrate reducer is a drilling fluid additive that can effectively control the filtration loss of drilling fluid to ensure the safe and efficient exploitation of oilfields. It is the most widely used treatment agent in oilfields. Due to its moderate conditions and controllable procedure, alkaline hydrolysis of high-purity waste polyacrylonitrile has been utilized for decades to produce filtrate reducer on a large scale in oilfields.
View Article and Find Full Text PDFProbiotics are essential to improve the health of the host, whereas maintaining the viability of probiotics in harsh environments remains a challenge. Polysaccharides have non-toxicity, excellent biocompatibility, and outstanding biodegradability, which can protect probiotics by forming a physical barrier and show a promising prospect for probiotic delivery. In this review, we summarize polysaccharides commonly used for probiotic microencapsulation and introduce the microencapsulation technologies, including extrusion, emulsion, spray drying, freeze drying, and electrohydrodynamics.
View Article and Find Full Text PDFIntestinal metabolism-related diseases, such as constipation, inflammatory bowel disease, irritable bowel syndrome, and colorectal cancer, could be associated with the dysfunction of intestinal mitochondria. The mitochondria of intestinal epithelial cells are of great significance for promoting intestinal motility and maintaining intestinal metabolism. It is necessary for the prophylaxis and therapy of intestinal metabolism-related diseases to improve mitochondrial function.
View Article and Find Full Text PDFThe off-the-shelf small-diameter vascular grafts (SDVGs) have inferior clinical efficacy. Red blood cell membrane (Rm) has easy availability and multiple bioactive components (such as phospholipids, proteins, and glycoproteins), which can improve the clinic's availability and patency of SDVGs. Here we developed a facile approach to preparing an Rm-functionalized poly-ε-caprolactone/poly-d-lysine (Rm@PCL/PDL) tube by co-incubation and single-step rolling.
View Article and Find Full Text PDFTo understand fumaric acid sludge (FAS) systematically and comprehensively and find out how to utilize it, we conducted a series of characterization analyses on FAS. Fourier transform infrared (FT-IR) Spectra shows that the main component of FAS is fumaric acids and also contains a small amount of silicate. The nuclear magnetic resonance hydrogen (H-NMR) spectrum also shows that fumaric acid accounted for a large proportion of FAS.
View Article and Find Full Text PDFIron ore pellets not only have excellent metallurgical and mechanical properties but are also essential raw materials for improving iron and steel smelting in the context of the increasing global depletion of high-grade iron ore resources. Organic polymers, as important additive components for the production of high-quality pellets, have a significant impact on the formation as well as the properties of pellets. In this review, the mechanisms of organic polymers on the pelletizing properties, bursting temperature, and pellet strength at low and high temperatures, as well as the existing measures and mechanisms to improve the high-temperature strength of the organic binder pellets are systematically summarized.
View Article and Find Full Text PDFIn recent years, with the increase in requirements for horizontal wells, ultra-high depth wells, small wells and branching wells, it has become increasingly important to deal with the conflict between drilling safety and bottomhole friction. In order to meet the requirements of complex boreholes and deepwater drilling processes, it is crucial to improve the performance of ester-based lubricants. Oleic acid esters are relatively stable and have high lubricity at low temperature, however, these can be hydrolyzed at high temperature.
View Article and Find Full Text PDFWith the development of the oil industry and the increasingly complex drilling environment, the performance of drilling fluids has to be constantly improved. In order to solve the problem of bentonite dispersion and hydration in a saline medium, a drilling fluid additive with good performance and acceptable cost was sought. The effects of several water-soluble polymers, such as cellulose polymers, synthetic polymers and natural polymers, on the rheology and gel suspension stability of calcium-based bentonite were compared in this study.
View Article and Find Full Text PDFNanocellulose (NC), including cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial cellulose (BC), has attracted a great deal of attention as a green packaging material. NC can protect food from pathogen adhesion and can be degraded by microorganisms after being discarded. In this review, we introduce preparations of NC-based film, including layer by layer (LbL) assembly, electrospinning, coating, extrusion, casting, vacuum filtration, and immersion.
View Article and Find Full Text PDFAdsorbents for wastewater treatment have evolved from scientific adsorbents to natural adsorbents. In this study, a humic acid-bentonite polymer (HBP) composite comprising humic acid, bentonite, and anionic polyacrylamide was integrated into an anionic polyacrylamide (aPAM) polymer matrix as an adsorbent pellet with N, N-methylene-bis-acrylamide (MBA), sodium tetraborate pentahydrate and chromium chloride is used as a novel adsorbent to remove Ni, Cd and Pb ions from aqueous solution. Sorption of these ions onto HBP is studied as a function of pH, adsorbent dosage, initial metal ion concentration, humic acid, and bentonite properties to evaluate adsorption efficiency.
View Article and Find Full Text PDFFumaric acid sludge (FAS) by-produced from phthalic anhydride production wastewater treatment contains a large amount of refractory organic compounds with a complex composition, which will cause environmental pollution unless it is treated in a deep, harmless manner. FAS included saturated carboxylic acid, more than 60%, and unsaturated carboxylic acid, close to 30%, which accounted for the total mass of dry sludge. A new oil well drilling fluid filtrate loss reducer, poly(AM-AMPS-FAS) (PAAF), was synthesized by copolymerizing FAS with acrylamide (AM) and 2-acrylamide-2-methyl propane sulfonic acid (AMPS).
View Article and Find Full Text PDFPlant press slag (PPS) containing abundant cellulose and starch is a byproduct in the deep processing of fruits, cereals, and tuberous crops products. PPS can be modified by using caustic soda and chloroacetic acid to obtain an inexpensive and environmentally friendly filtrate reducer of drilling fluids. The optimum mass ratio of m:m:m is 1:1:2, the optimum etherification temperature is 75 °C, and the obtained product is a natural mixture of carboxymethyl cellulose and carboxymethyl starch (CMCS).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
May 2022
Analysis of mixture via chromatographic-spectroscopic and analogous experiments is a common task in analytical chemistry. A 2D/nD asynchronous spectrum is effective in retrieving spectra of pure substances even if different components cannot be separated. However, noise in the 2D/nD asynchronous spectrum becomes a bottleneck in the analysis.
View Article and Find Full Text PDFReducing the cost of pellet additives as a substitute for reducing bentonite binder is an important research direction of new pellet additives. There are some industrial solid wastes that have the similar physical and chemical properties to bentonite, and SiO content of them may be much lower than bentonite, but also contains a lot of FeO, AlO, MgO, BO and other components beneficial to the quality of pellets, which have been paid more attention by many pellet workers. In this review, the effect mechanism of FeO, NaO/KO, AlO, SiO, CaO, MgO and BO in the industrial solid wastes on the fired strength and reduction expansion of pellets were systematically summarized.
View Article and Find Full Text PDFDental mold gypsum materials require fine powder, appropriate liquidity, fast curing, and easy-to-perform clinical operations. They require low linear expansion coefficient and high strength, reflecting the master model and facilitating demolding. In this article, the suitable accelerators and reinforcing agents were selected as additives to modify dental gypsum.
View Article and Find Full Text PDFSmall-diameter vascular grafts (inner diameter < 6 mm) are useful in treating cardiovascular diseases. The off-the-shelf small-diameter vascular grafts for clinical applications remain a great limitation owing to their thrombogenicity or intimal hyperplasia. Herein, bilayer anticoagulant hydrogel tubes with poly(ε-caprolactone) (PCL) sheaths are prepared by freeze-thawing and electrospinning, which contain nanofibrillated cellulose (NFC)/poly(vinyl alcohol) (PVA)-heparin/poly-L-lysine nanoparticles tube as an inner layer and PCL sheath as an outer layer.
View Article and Find Full Text PDFPolysaccharide nanocrystals (PNs) are attractive pharmaceutical excipients due to their abundant surface hydroxyl groups, high surface charges, prominent mechanical properties, excellent fluidity, and good swelling properties. In this review, we summarize three kinds of PNs, including cellulose nanocrystals (CNCs), starch nanocrystals (SNCs), and chitin nanocrystals (ChNCs). We introduce the applications of PNs as stabilizers, adsorbents, film-forming materials, gel materials, disintegrants, and ointment matrices.
View Article and Find Full Text PDFPreviously, we demonstrated that the intensities of cross-peaks in a two-dimensional asynchronous spectrum could be enhanced using sequence change of the corresponding one-dimensional spectra. This unusual approach becomes useful when the determination of the sequential order of physicochemical events is not essential. However, it was not known whether the level of noise in the two-dimensional asynchronous spectrum was also escalated as the sequence of one-dimensional spectra changed.
View Article and Find Full Text PDFCarbohydr Polym
September 2020
Nanocellulose (NC) possesses low density, high aspect ratio, impressive mechanical properties, nanoscale dimensions, which shows huge potential applications as a reinforced filler. Polyolefin (PO), represented by polyethylene (PE) and polypropylene (PP), has been widely used in industries. Recently nanocellulose/polyolefin nanocomposites (NC/PO nanocomposites) have caught more attention from the application of automotive components, aerospace, furniture, building, home appliances, and sport.
View Article and Find Full Text PDFCarbohydr Polym
November 2019
Scaffolds based on nanocellulose (NC) have crucial applications in tissue engineering (TE) owing to the biocompatibility, water absorption, water retention, optical transparency, and chemo-mechanical properties. In this review, we summarize the scaffolds based on nanocellulose, including nanocrystalline cellulose and nanofibrillated cellulose. We compare four representative methods to prepare NC-based scaffolds, containing electrospinning, freeze-drying, 3D printing, and solvent casting.
View Article and Find Full Text PDFAntibiotics that are most used to cure bacterial infections in the clinic result in the imbalance of intestinal microflora, destroy the intestinal barrier, and induce bacterial resistance. There is an urgent need for antibacterial agent therapy for bacterial infections that does not destroy intestinal microflora. Herein, we applied 4,6-diamino-2-pyrimidinethiol (DAPT)-coated Au nanoparticles (D-Au NPs) for therapy of bacterial infection induced by Escherichia coli ( E.
View Article and Find Full Text PDFEven though iron oxide (FeO) nanoparticles are promising materials for magnetic resonance imaging (MRI) contrast agents, their biocompatibility and targeting efficacy still need to be improved. Herein, we modified glycyrrhetinic acid (GA) groups on FeO nanoparticles (FeO@cGlu-GA) for liver tumor-targeted imaging. To evaluate the biocompatibility of these nanoparticles, we studied their cytotoxicity, hemolysis, and hepatotoxicity.
View Article and Find Full Text PDFIn recent years, nanocellulose-based antimicrobial materials have attracted a great deal of attention due to their unique and potentially useful features. In this review, several representative types of nanocellulose and modification methods for antimicrobial applications are mainly focused on. Recent literature related with the preparation and applications of nanocellulose-based antimicrobial materials is reviewed.
View Article and Find Full Text PDFCuprous oxide is firstly created on acidized sepiolite (AS) by a simple deposition method for photocatalytic degradation of the red water produced from 2,4,6-trinitrotoluene (TNT) manufacturing. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), ultraviolet-visible diffuse reflection absorptive spectroscopy (UV-vis/DRS), and Fourier transform infrared (FT-IR) spectroscopy are used to characterize the photocatalyst composites. Gas chromatography/mass spectrometry (GC/MS) is employed to determine the organic constituents in the red water.
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