Novel Cellulose Acetate-Based Monophasic Hybrid Membranes for Improved Blood Purification Devices: Characterization under Dynamic Conditions

A novel cellulose acetate-based monophasic hybrid skinned amine-functionalized CA-SiO2-(CH2)3NH2 membrane was synthesized using an innovative method which combines the phase inversion and sol-gel techniques. Morphological characterization was performed by scanning electron microscopy (SEM), and the chemical composition was analyzed by Fourier transform infrared spectroscopy in attenuated total reflection mode (ATR-FTIR). The characterization of the monophasic hybrid CA-SiO2-(CH2)3NH2 membrane in terms of permeation properties was carried out in an in-house-built single hemodialysis membrane module (SHDMM) under dynamic conditions. Permeation experiments were performed to determine the hydraulic permeability (Lp), molecular weight cut-off (MWCO) and the rejection coefficients to urea, creatinine, uric acid, and albumin. SEM confirmed the existence of a very thin (<1 µm) top dense layer and a much thicker bottom porous surface, and ATR-FTIR showed the main bands belonging to the CA-based membranes. Permeation studies revealed that the Lp and MWCO of the CA-SiO2-(CH2)3NH2 membrane were 66.61 kg·h−1·m−2·bar−1 and 24.5 kDa, respectively, and that the Lp was 1.8 times higher compared to a pure CA membrane. Furthermore, the CA-SiO2-(CH2)3NH2 membrane fully permeated urea, creatinine, and uric acid while completely retaining albumin. Long-term filtration studies of albumin solutions indicated that fouling does not occur at the surface of the CA-SiO2-(CH2)3NH2 membrane.

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Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose–Acetate/Silica/Titania and Cellulose–Acetate/Titania Membranes

Membranes ◽

10.3390/membranes10090195 ◽

2020 ◽

Vol 10 (9) ◽

pp. 195 ◽

Cited By ~ 1

Author(s):

Inês Peixoto ◽

Mónica Faria ◽

M. Clara Gonçalves

Keyword(s):

Cellulose Acetate ◽

Phase Inversion ◽

Sol Gel ◽

Asymmetric Structure ◽

Hydraulic Permeability ◽

Icp Oes ◽

Phase Inversion Technique ◽

In Series ◽

Covalently Bound

Two series of novel integral asymmetric monophasic hybrid membranes, cellulose acetate/silica/titania (CA/SiO2/TiO2—series 1) and cellulose acetate/titania (CA/TiO2—series 2), were developed by the coupling of sol-gel technology and a modified version of the phase inversion technique. SEM micrographs confirmed the integral asymmetric structure of all membranes. ATR-FTIR and ICP-OES results showed that, for the membranes in series 1, TiO2 is covalently bound to SiO2, which, in turn, is covalently bound to CA, while for the membranes in series 2, TiO2 is directly and covalently bound to the CA matrix. Permeation experiments revealed that the permeation performance of the membranes in series 1 is unaffected by the introduction of TiO2. In contrast, the introduction of TiO2 in the series 2 membranes increased the hydraulic permeability by a factor of at least 2 when compared to the pristine CA membrane and that incremental additions of TiO2 further increased the Lp.

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Cellulose Acetate Reverse Osmosis Membrane Structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095893 ◽

1972 ◽

Vol 30 ◽

pp. 528-529

Author(s):

H. K. Plummer ◽

E. Eichen ◽

C. D. Melvin

Keyword(s):

Cellulose Acetate ◽

Reverse Osmosis ◽

Membrane Structure ◽

Freeze Drying ◽

Dense Layer ◽

Water Removal ◽

Reverse Osmosis Membrane ◽

Correct Interpretation ◽

Electron Image ◽

Scanning Electron

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.

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Association between polymorphism at IGF-1 rs35767 gene locus and long-term decline in renal function: a Japanese retrospective longitudinal cohort study

BMC Nephrology ◽

10.1186/s12882-021-02408-9 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Kosuke Honda ◽

Satoru Kuriyama ◽

Kimiyoshi Ichida ◽

Tomoko Nakano ◽

Naoki Sugano ◽

...

Keyword(s):

Blood Pressure ◽

Metabolic Syndrome ◽

Renal Function ◽

Uric Acid ◽

Cohort Study ◽

Serum Uric Acid Level ◽

Human Growth ◽

Longitudinal Cohort Study ◽

Longitudinal Cohort

Abstract Background Insulin-like growth factor-1 (IGF-1) acts on glucose and protein metabolism and human growth and also influences blood pressure and renal function. This study investigated whether the single-nucleotide polymorphism of IGF-1, rs35767, plays a role in metabolic syndrome indicators, including blood pressure, glucose metabolism, uric acid levels, and renal function. Methods In this retrospective longitudinal cohort study, blood samples from 1506 Japanese individuals were collected and used for genotyping for variant rs35767: T > C in the IGF-1 upstream promoter. Data were analyzed to identify associations between IGF-1 genotypes and patient biochemical parameters, including the components of metabolic syndrome and the long-term change in renal function. Results The cohort rs35767 genotypes included 650 CC carriers (43.2%), 687 TC carriers (45.6%), and 169 TT carriers (11.2%). Multiple regression analysis revealed no association between IGF-1 genotype and blood pressure, glycated hemoglobin level, and serum uric acid level. However, in females, blood pressure was negatively correlated with the TT genotype. Longitudinal observation revealed that the decline in eGFR over 10 years was greater in TT (− 18.51 ± 1.04 mL/min/1.73m2) than in CC carriers (− 16.38 ± 0.52 mL/min/1.73m2; P < 0.05). Conclusion The present study suggests that renal function declines faster in individuals with the TT genotype at the IGF-1 rs35767 locus than in those with the CC genotype, suggesting that the TT genotype is associated with the long-term chronological decline in renal function.

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Photocatalytic Activity Enhancement of Low-pressure Cold-Sprayed TiO2 Coatings Induced by Long-term Water Vapor Exposure

Journal of Thermal Spray Technology ◽

10.1007/s11666-021-01244-5 ◽

2021 ◽

Cited By ~ 1

Author(s):

Seremak Wioletta ◽

Baszczuk Agnieszka ◽

Jasiorski Marek ◽

Gibas Anna ◽

Winnicki Marcin

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Water Vapor ◽

Sol Gel ◽

Low Pressure ◽

Oxygen Depletion ◽

Amorphous Structure ◽

Industrial Applications ◽

Additional Parameter

AbstractThis work shows that the titanium dioxide coatings obtained by low-pressure cold gas spraying with the use of the sol–gel amorphous TiO2 powder are characterized by photocatalytic activity despite their partial amorphous content. Moreover, the research outcome suggests that the decomposition rate of organic pollutants is enhanced after long-term exposure to moisture. The condensation humidity test is not detrimental to the continuity and integrity of the coating, but the phase composition of coatings changes—with the exposure to water vapor, the portion of the amorphous phase crystallizes into brookite. The mechanism responsible for the conversion of amorphous TiO2 into brookite is attributed to the water-driven dissolution and reprecipitation of TiO6 octahedra. It has been shown that an additional parameter necessary for the stabilization of the brookite is the oxygen depletion of the amorphous structure of titanium dioxide. Considering the results presented in this paper and the advantages of a portable, low-pressure cold spray system for industrial applications, it is expected that TiO2 coatings produced from a sol–gel feedstock powder can be further developed and tested as efficient photocatalysts.

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Sodium Solid Electrolytes: NaxAlOy Bilayer-System Based on Macroporous Bulk Material and Dense Thin-Film

Materials ◽

10.3390/ma14040854 ◽

2021 ◽

Vol 14 (4) ◽

pp. 854

Author(s):

Antonia Hoppe ◽

Cornelius Dirksen ◽

Karl Skadell ◽

Michael Stelter ◽

Matthias Schulz ◽

...

Keyword(s):

Pore Size ◽

Bulk Material ◽

Sol Gel ◽

Dense Layer ◽

X Ray Diffraction ◽

Bilayer System ◽

Step Procedure ◽

Short Circuits ◽

Α Al2o3 ◽

Sol Gel Synthesis

A new preparation concept of a partially porous solid-state bilayer electrolyte (BE) for high-temperature sodium-ion batteries has been developed. The porous layer provides mechanical strength and is infiltrated with liquid and highly conductive NaAlCl4 salt, while the dense layer prevents short circuits. Both layers consist, at least partially, of Na-β-alumina. The BEs are synthesized by a three-step procedure, including a sol-gel synthesis, the preparation of porous, calcined bulk material, and spin coating to deposit a dense layer. A detailed study is carried out to investigate the effect of polyethylene oxide (PEO) concentration on pore size and crystallization of the bulk material. The microstructure and crystallographic composition are verified for all steps via mercury intrusion, X-ray diffraction, and scanning electron microscopy. The porous bulk material exhibits an unprecedented open porosity for a NaxAlOy bilayer-system of ≤57% with a pore size of ≈200–300 nm and pore volume of ≤0.3 cm3∙g−1. It contains high shares of crystalline α-Al2O3 and Na-β-alumina. The BEs are characterized by impedance spectroscopy, which proved an increase of ionic conductivity with increasing porosity and increasing Na-β-alumina phase content in the bulk material. Ion conductivity of up to 0.10 S∙cm−1 at 300 °C is achieved.

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Evaluation of clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2021-0034 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Gunce Basarir ◽

Bahar Ozcabi ◽

Ozden Aksu Sayman ◽

Hatice Ozturkmen Akay ◽

Feyza M. Yildiz

Keyword(s):

Uric Acid ◽

Density Lipoprotein ◽

Thyroid Stimulating Hormone ◽

Fasting Insulin ◽

Obese Children ◽

Pubertal Stage ◽

Alcoholic Fatty Liver ◽

Group 2 ◽

Group 1

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) is a common obesity-related comorbidity in childhood. In this study, we aimed to evaluate predictors of NAFLD by comparing clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis. Methods Two hundred and eight obese children aged 6–18 years were included. The patients were divided into group 1 (patients with NAFLD, n=94) and group 2 (patients without NAFLD, n=114). Anthropometric measurements, pubertal stage, lipid profiles, fasting glucose and insulin, homeostatic model of assessment for insulin resistance (HOMA-IR), uric acid, total bilirubin, alanine aminotransferase (ALT), blood urea nitrogen, thyroid-stimulating hormone and free thyroxine parameters were compared retrospectively. Results The mean body weight, body mass index (BMI), height, tri-ponderal mass index (TMI), insulin, HOMA-IR, triglyceride, ALT and uric acid values were significantly higher, while high-density lipoprotein-cholesterol (HDL-C) values were significantly lower in group 1. The 70.7% of obese children with hepatosteatosis and 83.9% of those without hepatosteatosis were correctly estimated by parameters including age, gender, ALT, HDL-C, fasting insulin and uric acid values. Conclusions Since obesity-associated hepatosteatosis induces various long-term metabolic impacts in children, early detection is of critical importance. Age, gender, TMI, BMI, ALT, HDL-C, fasting insulin and uric acid values may help to predict the risk of hepatosteatosis. Besides, we assessed whether TMI compared to BMI does not have a better utility in estimating obesity-induced hepatosteatosis in children. This is the first study to show the association between TMI and hepatosteatosis in children.

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The Ferroelectric and Electrical Properties of CaBi4Ti4O15 Thin Films Prepared by Sol-Gel Technology

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.891 ◽

2011 ◽

Vol 239-242 ◽

pp. 891-894 ◽

Cited By ~ 3

Author(s):

Tsung Fu Chien ◽

Jen Hwan Tsai ◽

Kai Huang Chen ◽

Chien Min Cheng ◽

Chia Lin Wu

Keyword(s):

Thin Film ◽

Thin Films ◽

Sol Gel ◽

Morphological Characterization ◽

Experimental Result ◽

X Ray Diffraction ◽

Solution Deposition ◽

Capacitance Voltage ◽

Preferential Crystal Orientation

In this study, thin films of CaBi4Ti4O15with preferential crystal orientation were prepared by the chemical solution deposition (CSD) technique on a SiO2/Si substrate. The films consisted of a crystalline phase of bismuth-layer-structured dielectric. The as-deposited CaBi4Ti4O15thin films were crystallized in a conventional furnace annealing (RTA) under the temperature of 700 to 800°C for 1min. Structural and morphological characterization of the CBT thin films were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The impedance analyzer HP4294A and HP4156C semiconductor parameters analyzer were used to measurement capacitance voltage (C-V) characteristics and leakage current density of electric field (J-E) characteristics by metal-ferroelectric-insulator- semiconductor (MFIS) structure. By the experimental result the CBT thin film in electrical field 20V, annealing temperature in 750°C the CBT thin film leaks the electric current is 1.88x10-7A/cm2and the memory window is 1.2V. In addition, we found the strongest (119) peak of as-deposited thin films as the annealed temperature of 750°C

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