Acetyl Cellulose Research Articles

Anti-Inflammatory Property Establishment of Fulvic Acid Transdermal Patch in Animal Model

The formulation of the transdermal patch with fulvic acid (FA) on an emulsion basis using pluronic Kolliphor® p237 as a permeability enhancer was developed and studied for anti-inflammatory properties. FA was isolated from the peat in the Nizhny Novgorod region of Russia and characterized as a potential active pharmaceutical ingredient. In vitro studies of the release of FA from the transdermal patch, as well as the FA penetration through the acetyl cellulose membrane using the Franz diffusion cell, showed its high efficiency (56% and 90%, respectively, in 8 h). In the in vivo experiment, qualitative and quantitative features of the rat knee caused by complete Freund’s adjuvant-induced arthritis (morphological changes, the FA influence on the biochemical indexes) were studied. The inflammatory process that developed within 15 days was accompanied by the activation of antioxidant oxidoreductase enzymes (by 50–70%), the increase in the cross-sectional diameter of the cartilage, and the increase in the values of marker indicators of the process of rheumatoid arthritis. Within 7 days of treatment, under the influence of FA, the values of ESR, RF, leukocytes, C-reactive protein, as well as the biochemical parameters characterizing oxidative stress (SOD, catalase, glutathione reductase, LDH, G6PD) normalized, and the edema reduced. These results may be useful for arthritis treatment using the transdermal patch with FA.

The Effect of Zinc Oxide Nanoparticles on Properties and Burn Wound Healing Activity of Thixotropic Xymedone Gels

Zinc oxide nanoparticles (ZnO NPs) modified by oxopyrymidine alcohol, also known as xymedone (Xym), were obtained and studied using FTIR, UV-vis, and fluorescent spectroscopy, and SEM, BET, powder XRD, and DLS analysis. A formulation of thixotropic hydrophilic gels containing Carbopol-based Xym and ZnO NPs was developed. A vertical Franz cell with a cellulose acetate membrane was used as a model to investigate the passive diffusion of the gel components by AAS. The gel components—Xym and ZnO NPs—were shown to penetrate through acetyl cellulose membrane within 5–7 h depending on an initial amount, and its values were in the range of 56–77%. The penetration of modified ZnO NPs by Xym was more effective in contrast to ZnO NPs without modification. The burn wound healing activity of ZnO NPs–Xym gel was demonstrated on a thermal burn wound model on rats. SOD and GR activity was increased by 30–35% during ZnO NPs–Xym gel treatment, the burn area on 10 postburn day decreased by 10% in contrast to a positive control, Methyluracyl®® ointment.

Formation of Nanochannels Using Polypropylene and Acetylcellulose for Stable Separators.

In this study, a polymer separator with enhanced thermal stability is prepared to solve the problem of thermal durability of lithium-ion battery separators. This separator is manufactured by coating a solution of acetyl cellulose and glycerin on polypropylene. The added glycerin reacts with the acetyl cellulose chains, helping the chains become flexible, and promotes the formation of many pores in the acetyl cellulose. To improve the thermal stability of the separator, a mixed solution of acetyl cellulose and glycerin was coated twice on the PP membrane film. Water pressure is applied using a water treatment equipment to partially connect the pores of a small size in each layer and for the interaction between the PP and acetyl cellulose. SEM is used to observe the shape, size, and quantity of pores. TGA and FT-IR are used to observe the interactions. Average water flux data of the separators is 1.42 LMH and the decomposition temperature increases by about 60 °C compared to the neat acetyl cellulose. It is confirmed that there is an interaction with PP between the functional groups of acetyl cellulose.

Acetyl Cellulose Film with 18-crown-6 Ether for Colorimetric Phosgene Detection.

The use of a cellulose detection film as a carrier for a colorimetric sensor to detect phosgene and allied compounds to be evaluated primarily visually is studied. For the case study, a benzimidazole-rhodamine dye and an acetyl cellulose film were selected. The detection complex was modified using cyclic ether 18-crown-6 to achieve more desirable analytic properties. The chromatic properties of detection film was verified using reflectance colorimetry in the visible light spectrum. The employed detection agent demonstrated high sensibility to phosgene vapours, but acid gases, acyl chlorides, base organic solvents, and in higher concentrations, even some organophosphorus substances interfered. The detection film application was adjusted to the in-situ preparation of simple detection devices (a spray or a marker) as well as to manufacture detection strips with beforehand excluded polymer film.

Production of Acetyl Cellulose from Agricultural Waste of Oil Palm Empty Fruit Bunches

In Indonesia especially in Lampung Province, there are a lot of oil palm empty fruit bunches (OPEFB) as an organic material waste. OPEFB is relatively inexpensive lignocellulose material as raw material of cellulose acetate or acetyl cellulose. In a business to bigger added value out of these natural renewable materials, the production of the acetyl cellulose was performed well by the acetylation of cellulose from OPEFB using different methods. These were extensively characterized using thermogravimetric analysis, Fourier transform infrared spectroscopy and X-ray diffraction. The results indicated that the acetyl cellulose resulted showed similar properties to cotton acetyl cellulose. Degree of substitution of the resultant acetyl cellulose from different methods was improved from 1.86 to 2.60.

The Effect of Aqueous–Ethanol Sodium Chloride Solutions on the Selectivity and Electrosurface Properties of an Acetyl Cellulose Membrane

The electrokinetic properties and selectivity of an acetyl cellulose membrane with respect to 0.0001 mol/L sodium chloride solutions in water–ethanol mixtures have been studied. The electrical conductivity, streaming potential, and filtration and selectivity characteristics of the membrane have been measured. It has been found that, in solutions with alcohol contents of 4 and 12%, the membrane selectivity with respect to sodium chloride is increased and decreased relative to that in an aqueous solution, respectively. No correlation between the membrane selectivity and its surface charge has been observed. The membrane has been found to possess a slight selectivity (20–26%) with respect to ethanol. It has been hypothesized that the solvation enthalpy of electrolyte ions changes differently in a free solution and membrane pores at different contents of ethanol in the mixtures, thereby affecting the membrane selectivity.

Determination of Hg2+ by Diphenylcarbazone Compound in Polymer Film

A sensitive optical sensor for determining Hg2+ concentration has been prepared by incorporating the indicator dye, diphenylcarbazone, into cellulose acetate polymer film. The sensor was fabricated by binding diphenylcarbazone to a cellulose acetate film that had been previously subjected to exhaustive base hydrolysis. The method is easy to perform and uses acetyl cellulose as a carrier. The results showed that the sensor has the ability to determine the Hg2+ concentration with ±6% error. Also, the adsorption capacity was 3.41 × 10-3 mmol/g.

Development of cellulose-based migratory and nonmigratory active packaging films

The main aim of this work is to develop a transparent bioactive cellulose acetate (CA) film for food packaging applications. The aim of the study is also to optimize the production methods for development of bulk and surface immobilized bioactive CA films. The vacuum drying method was optimized for the production of transparent CA films. The direct infusion and UV-assisted surface immobilization methods were investigated for the development of bioactive CA films. Reduction in the crystalline nature of CA was observed to be responsible for the production of transparent CA films. Thymol, with high antioxidant and antimicrobial properties, was examined to be the major active compound (>40%) present in the polar fraction of oregano. Retention of active compounds analyzed by High Performance Liquid Chromatography (HPLC), surface morphology analyzed by Atomic Force Microscopy (AFM), and surface chemistry analyzed by X-ray Photoelectron Spectroscopy (XPS) proved the efficiency of UV-assisted surface immobilization method. Acetyl cellulose films treated with UV irradiation at 312 nm were examined to have higher retention of active compounds. The bioactive CA films produced by bulk and surface immobilization methods showed >90% and ∼65% thymol retention, respectively. The UV-assisted surface immobilization method was found to decrease the mechanical and barrier properties of CA film. The bioactive CA films produced by bulk and surface immobilization methods were found to have retained the antioxidant and antimicrobial properties of the thymol.

Uniaxially well-aligned nanofiber arrays fabricated by electrospinning with a stable and low moving velocity jet

Aligned fibers in micro-/nano-scale have attracted more attention especially in tissue engineering field because cells can orientation growth along the fiber. However, it is still a huge technological challenge in achieving it as a result of the inherent bending instability of an electrospinning jet. Herein, we report a novel and simple spinning approach, in which low dielectric constant of dioxane was judiciously used as solvent for spinning dope, to obtain electrospinning jet with low induced charge, therefore eliminating electrically and aerodynamically driven bending instability, and forming a stable and low forward-moving velocity jet longer than 100 cm. This consequently allows for readily collecting and fabricating individual fibers, well-aligned ultrafine fiber arrays over large areas. Our approach has proved to be effective in preparing well-aligned ultrafine fibers from biodegradable poly(D, L-lactic acid) with different molecular mass, natural polymer acetyl cellulose and synthesized non-biodegradable polymer polystyrene.

Synthesis of cellulose/silica gel polymer hybrids via in-situ hydrolysis method

Homogeneous cellulose/silica gel polymer hybrids were prepared by hydrolysis of acetyl cellulose (AcCL) in a sol–gel reaction mixture of alkoxysilane such as tetramethoxysilane (TMOS). To a mixture of AcCL and TMOS in a mixed solvent of THF and methanol (v/v, 7/3), an HCl aqueous solution was added to initiate hydrolysis and condensation of the alkoxysilane. The resulting mixture was constantly stirred for 5 h and heated at 60 °C for two weeks to allow evaporation of the solvents. Consequently, corresponding transparent and homogeneous polymer hybrids could be obtained in a range of mass ratios (AcCL/TMOS = 1/5–1/2). In the FT-IR spectra, the absorption peaks corresponding to the acetyl group decreased as the amount of 0.1 M aqueous HCl solution increased, which indicates hydrolysis of acetyl groups of AcCL, whereas the intensity of the Si–O-Si stretching vibration peak increased. The thermal properties of the obtained polymer hybrids were evaluated by TG/DTA and DSC measurements.

Selectivity of biopolymer membranes using HepG2 cells.

Bioartificial liver (BAL) system has emerged as an alternative treatment to bridge acute liver failure to either liver transplantation or liver regeneration. One of the main reasons that the efficacy of the current BAL systems was not convincing in clinical trials is attributed to the lack of friendly interface between the membrane and the hepatocytes in liver bioreactor, the core unit of BAL system. Here, we systematically compared the biological responses of hepatosarcoma HepG2 cells seeded on eight, commercially available biocompatible membranes made of acetyl cellulose–nitrocellulose mixed cellulose (CA–NC), acetyl cellulose (CA), nylon (JN), polypropylene (PP), nitrocellulose (NC), polyvinylidene fluoride (PVDF), polycarbonate (PC) and polytetrafluoroethylene (PTFE). Physicochemical analysis and mechanical tests indicated that CA, JN and PP membranes yield high adhesivity and reasonable compressive and/or tensile features with friendly surface topography for cell seeding. Cells prefer to adhere on CA, JN, PP or PTFE membranes with high proliferation rate in spheriod-like shape. Actin, albumin and cytokeratin 18 expressions are favorable for cells on CA or PP membrane, whereas protein filtration is consistent among all the eight membranes. These results further the understandings of cell growth, morphology and spreading, as well as protein filtration on distinct membranes in designing a liver bioreactor.

Strain mapping with high spatial resolution across a wide observation range by digital image correlation on plastic replicas

In this study, a one-step replica method was applied at 0, 3, and 7% plastic strains in pearlitic steel. A microstructural digital image correlation was then performed on acetyl cellulose plastic replica surface images to obtain high spatial resolution strain maps across a wide observation range. In order to validate the digital image correlation on the replica, digital image correlation was also conducted on the chemically etched sample surface. Although the digital image correlation results were affected by replica shrinkage, its effect could be corrected by a simple experimental equation relating the shrinkage ratio dependence on the solvent immersion time. Reproducible strain maps were obtained for the plastic replica for any macroscopic strain, strain components, or degree of microscopic strain localization.

Biodegradation of polyether‐polyol‐based polyurethane elastomeric films: influence of partial replacement of polyether polyol by biopolymers of renewable origin

In this work we investigated the degradation process of polyether‐polyol‐based polyurethane (PUR) elastomeric films in the presence of a mixed thermophilic culture as a model of a natural bacterial consortium. The presence of PUR material in cultivation medium resulted in delayed but intensive growth of the bacterial culture. The unusually long lag phase was caused by the release of unreacted polyether polyol and tin catalyst from the material. The lag phase was significantly shortened and the biodegradability of PUR materials was enhanced by partial replacement (10%) of polyether polyol with biopolymers (carboxymethyl cellulose, hydroxyethyl cellulose, acetyl cellulose and actylated starch). The process of material degradation consisted of two steps. First, the materials were mechanically disrupted and, second, the bacterial culture was able to utilize abiotic degradation products, which resulted in supported bacterial growth. Direct utilization of PUR by the bacterial culture was observed as well, but the bacterial culture contributed only slightly to the total mass losses. The only exception was PUR material modified by acetyl cellulose. In this case, direct biodegradation represented the major mechanism of material decomposition. Moreover, PUR material modified by acetyl cellulose did not tend to undergo abiotic degradation. In conclusion, the modification of PUR by proper biopolymers is a promising strategy for reducing potential negative effects of waste PUR materials on the environment and enhancing their biodegradability.

Mesoporous supported cobalt catalysts for enhanced hydrogen production during cellulose decomposition

Two groups of cobalt (Co) catalysts, supported on SBA-15 and MCM-41, respectively, were prepared by incipient wetness impregnation and tested for their influence on the thermal decomposition of acetyl cellulose. γ-Al2O3 supported Co catalysts were investigated as a comparison. A thermogravimetric analyser coupled with a mass spectrometer (TG-MS) was used to examine the influence of catalyst loading, support material and the presence of additional water vapour on H2 production and selectivity. Normalization of the raw MS data enabled semi-quantitative analysis of the product gas distribution, which facilitated reliable comparison between different experimental conditions. Catalysts were characterized by physisorption, chemisorption, TGA, XRD, SEM and TEM. SBA-15 and MCM-41 supported catalysts significantly elevated the yield and selectivity of H2, under dry Ar and with the injection of additional water vapour, when compared with the γ-Al2O3 support. 15wt.%Co/SBA-15 and 10wt.%Co/MCM-41 were identified as the most active catalysts from the two groups with indicative yields of 202 and 303mlH2/g cellulose, respectively. The 10wt.%Co/MCM-41 catalyst gave with the highest H2 selectivity reaching 21.7% of the dry product gas.

Determination of trace alkaline phosphatase by affinity adsorption solid substrate room temperature phosphorimetry based on wheat germ agglutinin labeled with 8-quinolineboronic acid phosphorescent molecular switch and prediction of diseases

The 8-quinolineboronic acid phosphorescent molecular switch (abbreviated as PMS-8-QBA. Thereinto, 8-QBA is 8-quinolineboronic acid, and PMS is phosphorescent molecular switch) was found for the first time. PMS-8-QBA, which was in the “off” state, could only emit weak room temperature phosphorescence (RTP) on the acetyl cellulose membrane (ACM). However, PMS-8-QBA turned “on” automatically for its changed structure, causing that the RTP of 8-QBA in the system increased, after PMS-8-QBA-WGA (WGA is wheat germ agglutinin) was formed by reaction between –OH of PMS-8-QBA and –COOH of WGA. More interesting is that the –NH 2 of PMS-8-QBA-WGA could react with the –COOH of alkaline phosphatase (AP) to form the affinity adsorption (AA) product WGA-AP-WGA-8-QBA-PMS (containing –NH–CO– bond), which caused RTP of the system to greatly increase. Thus, affinity adsorption solid substrate room temperature phosphorimetry using PMS-8-QBA as labelling reagent (PMS-8-QBA-AA-SSRTP) for the determination of trace AP was established. The method had many advantages, such as high sensitivity (the detection limit (LD) was 2.5 zg spot −1. For sample volume of 0.40 μl spot −1, corresponding concentration was 6.2 × 10 −18 g ml −1), good selectivity (the allowed concentration of coexisting material was higher, when the relative error was ±5%), high accuracy (applied to detection of AP content in serum samples, the result was coincided with those obtained by enzyme-linked immunoassay), which was suitable for the detection of trace AP content in serum samples and the forecast of human diseases. Meanwhile, the mechanism of PMS-8-QBA-AASSRTP was discussed. The new field of analytical application and clinic diagnosis technique of molecule switch are exploited, based on the phosphorescence characteristic of PMS-8-QBA, the AA reaction between WGA and AP, as well as the relation between AP content and human diseases. The research results promote the development and interpenetrate among molecule switch technique, lectin science and SSRTP.

Determination of Glucose by Affinity Adsorption Solid Substrate‐room Temperature Phosphorimetry Based on Triticum Vulgare Lectin Labeled with Silicon Dioxide Nanoparticle Containing Fluorescein Isothiocyanate

Abstract In the presence of heavy atom perturber Pb2+, silicon dioxide nanoparticle containing fluorescein isothiocyanate (FITC‐SiO2) could emit a strong and stable room temperature phosphorescence (RTP) signal on the surface of acetyl cellulose membrane (ACM). It was found in the research that a quantitative specific affinity adsorption (AA) reaction between triticum vulgare lectin (WGA) labeled with luminescent nanoparticle and glucose (G) could be carried on the surface of ACM. The product (WGA‐G‐WGA‐FITC‐SiO2) of the reaction could emit a stronger RTP signal, and the ΔIp had linear correlation to the content of G. According to the facts above, a new method to determine G by affinity adsorption solid substrate room temperature phosphorimetry (AA‐SS‐RTP) was established, based on WGA labeled with FITC‐SiO2. The detection limit (LD) of this method calculated by 3Sb/k was 0.47 pg·spot−1 (corresponding to a concentration value 1.2×10−9 g·mL−1, namely 5.3×10−9 mol·L−1), the sensitivity was high. Meanwhile, the mechanism for the determination of G by AA‐SS‐RTP was discussed.

Preparation and ecotoxicity assessment of new biodegradable polyurethane foams

Flexible biodegradable polyurethane foams (BIO-PUR) were prepared by a one-shot process using commercially available coreactants and modified by substituting biodegradable additive based on the acetylated starch (AS), acetylcellulose (AC), 2-hydroxyethylcellulose (HEC) and carboxymethylcellulose sodium salt (CMC) for 5 or 10 wt% of commercial polyether polyol. The BIO-PUR foams were characterized by FTIR, TGA and polarization microscopy. Ecotoxicity of BIO-PUR foams freshwater extracts was evaluated using the alternative crustacean toxicity test Thamnotoxkit F. Values of toxicity were expressed as percentage mortality of the instars II–III larvae of freshwater fairy shrimps (Thamnocephalus platyurus) dependence on the effect criterion of the respective assay. The leaches of BIO-PUR foams modified with 5 or 10 wt% of HEC showed higher toxicity then other BIO-PUR foams, whereas leaches of BIO-PUR with 5wt% of AS and 10wt% of AC were even less toxic than REF. PUR foam.

Determination of alkaline phosphatase based on affinity adsorption solid-substrate room temperature phosphorimetry using rhodamine 6G–dibromoluciferin luminescent nanoparticle to label lectin and prediction of diseases

In the presence of heavy atom perturber LiAc, the silicon dioxide nanoparticle containing rhodamine 6G (R) and dibromoluciferin (D) (R-D-SiO 2) can emit strong and stable solid-substrate room temperature phosphorescence signal of R (λ ex/λ em = 481/648 nm) and D (λ ex/λ em = 457/622 nm) on the surface of acetyl cellulose membrane (ACM). R-D-SiO 2 is used to label triticum vulgare lectin (WGA). Then two types of affinity adsorption reactions, R-D-SiO 2-WGA- alkaline phosphatase (ALP) (direct method) and WGA-ALP-WGA-R-D-SiO 2 (sandwich method), are carried out on ACM. The conditions and the analytical characteristics for the determination of ALP using affinity adsorption solid-substrate room temperature phosphorimetry (AA-SS-RTP) were studied. For a 0.40-μl drop of sample, results show that the detection limits of the sandwich method are 0.16 ag spot −1(457/622 nm) and 0.17 ag spot −1(481/648 nm), and the detection limits of the direct method are 0.41 ag spot −1 (457/622 nm) and 0.44 ag spot −1 (481/648 nm). The contents of ALP in human serum correlated well with those obtained by enzyme-linked immunoassay. This study shows that AA-SS-RTP whether by the sandwich method or the direct method, can combine very well the characteristics of both high sensitivity of SS-RTP and specificity of the immunoreaction. Simultaneously, whether the phosphorescence excitation/emission wavelength of either R or D in R-D-SiO 2 is chosen to determine ALP, this can promote the agility and widen the adaptability of AA-SS-RTP.

Affinity Adsorption Solid Substrate‐Room Temperature Phosphorimetry for the Determination of Alkaline Phosphatase

In the presence of Pb(Ac)2, the silicon dioxide nanoparticle containing rhodamine 6G (R‐SiO2) can emit strong and stable solid substrate‐room temperature phosphorescence (SS‐RTP) signal on the surface of acetyl cellulose membrane (ACM) at λex/λem=482/649 nm. It was found in the research that specific affinity adsorption reaction between triticum vulgare lectin (WGA) (which was labeled with luminescent silicon dioxide nanoparticle) and alkaline phosphatase (AP) can be carried out on the surface of ACM. The product of the reaction can emit stronger SS‐RTP signal. A new method of SS‐RTP for the determination of AP was established, based on an affinity adsorption reaction between AP and WGA labeled with nanoparticles containing rhodanime 6G luminescent molecules. The linear range of this WGA‐AP‐WGA‐R‐SiO2 method is 1.00–360.00 ag AP spot−1 (sample volume: 0.40 µL spot−1, corresponding concentration range: 2.50–900.00 fg mL−1). The regression equation of working curve is ΔIp=16.24+0.8856 mAP (ag spot−1), r=0.9993. Detection limit of this method calculated by 3Sb/k is 0.14 ag spot−1. After 11‐fold replicate measurements, RSD are 3.9% and 3.1% for the systems containing 1.00 and 360.00 ag AP spot−1, respectively. Compared with R‐SiO2‐WGA‐AP method (detection limit: 0.45 ag spot−1, corresponding concentration range: 2.00–320.00 ag spot−1), the sensitivity of WGA‐AP‐WGA‐R‐SiO2 method was obviously improved and the linear range was wider. The sensitivity, accuracy, and precision of this method are high. It has been successfully applied to determine AP in human serum.

Transient rheological behavior of lyotropic (acetyl)(ethyl)cellulose/m-cresol solutions

The chiroptical properties and transient rheological behavior of (acetyl)(ethyl)cellulose (AEC) m-cresol liquid crystalline solutions have been investigated. Chiroptical properties were manipulated through (i) increasing degree of acetylation of ethyl cellulose (EC), and (ii) blending AEC with EC. At the same average degree of acetylation (DA), the chiroptical properties of pure AEC were different from those of the EC/AEC mixtures. However, at the same DA, the AEC and mixed AEC/EC solutions showed similar steady state flow and oscillatory behaviors, but the transient behaviors were different. At high flow rates the mixed AEC/EC solutions exhibited double recoil after cessation of steady-state flow, whereas the AEC solutions showed double recoil only in the high DA AEC solutions. All solutions, pure and mixed, had the same stress relaxation behavior. Both pitch and handedness affected the transient behavior. After cessation of high shear rate flow, the rate of modulus evolution decreased with increasing pitch, and was faster in right-handed mesophases than in left-handed ones at a similar pitch.