Cellulose Ester Research Articles

A sustainable approach for providing water repellency in textiles by using long-chain cellulose esters

A sustainable approach for providing water repellency in textiles by using long-chain cellulose esters

Evaluation of the alternating magnetic field (AMF) influence in catalytic activities of enzymes immobilized into magnetic graphene oxide: A new approach

The conventional methods of production of biofuels generate hazardous by-products, one way to reduce them, by using reusable enzymatic process that requires insoluble enzyme carriers. This investigation allowed the obtention of magnetic graphene oxide (MGO) carrier containing aminosilane functional groups with and without the crosslinker glutaraldehyde. Thus, it was possible to immobilize cellulases and lipases enzymes and evaluate its enzymatic activity in normal conditions, as well as the novelty that was under alternating magnetic field (AMF) conditions. Through enzymatic essays it was determined the optimal working activities for both enzymes using these two magnetic carriers, being pH 4 and 60ºC for cellulases and pH 5 and 50ºC for lipase. Different frequencies were used during AMF test (20, 30, 50 and 70 kHz) and it was confirmed for both groups that with the increase in frequency during the reaction, the less pronounced will be the activity decrease at pH values different from the optimal condition. Due to magnetic properties from the carrier and the medium reaction used the recycle test was satisfactory for the two immobilized groups of the cellulase enzyme, being recycled 9 times without losses greater than 50 % of relative activity. As for the two groups of immobilized lipases, drastic decreases in activity were observed, possibly caused by the strong enzyme/substrate interaction. For both groups of immobilized enzymes, an inhibitory behavior of the glutaraldehyde reagent, widely used as an enzyme/carrier cross-linker, was also observed. Nevertheless, the immobilization of cellulase and lipases enzymes into MGO derivates shows a promising and suitable strategy for the conversion of cellulose and long-chain acyl esters into value-added inputs.

Tensile and Surface Wettability Properties of the Solvent Cast Cellulose Fatty Acid Ester Films.

Thermoplastic cellulose esters are promising materials for bioplastic packaging. For that usage, it is important to understand their mechanical and surface wettability properties. In this study, a series of cellulose esters are prepared, such as laurate, myristate, palmitate, and stearate. The aim of the study is to investigate the tensile and surface wettability properties of the synthesized cellulose fatty acid esters to understand their suitability as a bioplastic packaging material. Cellulose fatty acid esters are first synthesized from microcrystalline cellulose (MCC), then dissolved in pyridine solution, and after the solvent cast into thin films. The cellulose fatty acid ester acylation process is characterized by the FTIR method. Cellulose esters hydrophobicity is evaluated with contact angle measurements. The mechanical properties of the films are tested with the tensile test. For all the synthesized films, FTIR provides clear evidence of acylation by showing the presence of characteristic peaks. Films' mechanical properties are comparable to those of generally used plastics such as LDPE and HDPE. Furthermore, it appears that with an increase in the side-chain length, the water barrier properties showed improvement. These results show that they could potentially be suitable materials for films and packaging materials.

Polyethersulfone (PES) Filters Improve the Recovery of Legionella spp. and Enhance Selectivity against Interfering Microorganisms in Water Samples.

In the analysis of water samples, the type of filtration membrane material can influence the recovery of Legionella species, although this issue has been poorly investigated. Filtration membranes (0.45 µm) from different materials and manufacturers (numbered as 1, 2, 3, 4, and 5) were compared: mixed cellulose esters (MCEs), nitrocellulose (NC), and polyethersulfone (PES). After membrane filtration of samples, filters were placed directly onto GVPC agar and incubated at 36 ± 2 °C. The highest mean counts of colony-forming units and colony sizes for Legionella pneumophila and Legionella anisa were obtained with PES filters (p < 0.001). All membranes placed on GVPC agar totally inhibited Escherichia coli and Enterococcus faecalis ATCC 19443 and ATCC 29212, whereas only the PES filter from manufacturer 3 (3-PES) totally inhibited Pseudomonas aeruginosa. PES membrane performance also differed according to the manufacturer, with 3-PES providing the best productivity and selectivity. In real water samples, 3-PES also produced a higher Legionella recovery and better inhibition of interfering microorganisms. These results support the use of PES membranes in methods where the filter is placed directly on the culture media and not only in procedures where membrane filtration is followed by a washing step (according to ISO 11731:2017).

Deployment of Superhydrophilic and Super-antifouling Cr-soc-MOF-1-Based Membrane for Ultrafast Separation of Stabilized Oil-in-Water Emulsions.

In spite of massive progress in oil-water separation, attributable to the use of advanced materials, the separation process faces challenges such as low permeance and fouling problems. Therefore, superwettable materials used in several fields are considered potential candidates for oily wastewater treatment. Metal-organic frameworks (MOFs) are receiving more and more interest in various separation applications due to their wide potential applications. Nevertheless, MOFs have been rarely explored for separating stabilized oil-in-water emulsions due to the difficulty in finding highly hydrolytic stable MOF candidates for this application. Furthermore, oil can clog water-stable materials owing to its high density, causing the degradation of MOF particles. As a result, there is a need to develop better MOF materials that can fulfill these requirements. Herein, we have explored Cr-soc-MOF-1 as a candidate for this application and deployed it as a membrane, which exhibited superhydrophilicity and underwater superoleophobicity for separating stabilized oil-in-water emulsions. The Cr-soc-MOF-1 membranes were synthesized by assembling the as-prepared MOF particles on a mixed cellulose ester substrate using a vacuum-assisted self-assembly technique. The Cr-soc-MOF-1 membrane exhibited ultrahigh water permeance (7465.9 L·m-2·h-1·bar-1), very high oil rejection (99.9%), and excellent anti-oil-fouling properties. The Cr-soc-MOF-1 membranes also exhibited excellent recyclability over 10 continuous separation cycles. Further, they exhibited an outstanding performance in separating various surfactant-stabilized oil-in-water emulsions. Thus, the Cr-soc-MOF-1 membranes exhibit a high potential in treating oily wastewater.

CO2 electroreduction to multicarbon products from carbonate capture liquid

CO2 electroreduction to multicarbon products from carbonate capture liquid

Древесина как химическое сырье. История и современность. V. Древесная целлюлоза как природное полимерное сырье. Часть I

The history of chemical processing development of the improved technical wood cellulose for the receiving of the additive derivatives, complex and simple ethers on their basis are considered. The historical transformation of technologies for the production of plant parchment, fiber, copper-ammonia fiber, synthesis of cellulose nitrates, xanthogenates and acetates, as well as methods for processing these derivatives into target products and materials is described in detail. The historical description of the preparation and prospects for the use of cellulose esters and modification of cellulose fiber hydrate is given. This article is the fifth in the cycle «Wood as a chemical raw material. History and modernity»; the previous parts were published in the journal Lesnoy vestnik / Forestry Bulletin (2020, v. 24, no 1, № 5; 2021, v. 25 no. 3; 2022, v. 26 no. 1).

One-pot synthesis of cellulose ester–graft–polylactide copolymers in an ionic liquid and the effect of graft-chain composition on their thermoplasticities and enzymatic degradabilities

With the aim of developing polymers having controlled thermoplasticities and biodegradabilities, a series of cellulose ester–graft–polylactide copolymers was synthesized using a homogeneous one-pot system in which the reaction medium was the ionic liquid 1-ethyl-3-methylimidazolium diethylphosphate (EmimDEP). The structures and compositions of the copolymers were controlled by varying the feed ratio of the carboxylic anhydride (acetic (C2), propionic (C3), or hexanoic (C6)) and L-lactide. In terms of side-chain substitution, the copolymers exhibited DSAcyl values of 0.7–2.7 and MSPLA values of 3.2–14.2. With increasing DSAcyl, the copolymers presented enhanced thermal stability and thermoplasticity due to the intermolecular interactions between the acyl groups and polylactide side-chains. The effect of graft-chain composition on mechanical properties and biodegradability was investigated using homogeneous cast films prepared with the copolymers. The mechanical properties were found to be affected by the carbon number of the acyl group (C2–C6), with higher carbon numbers imparting better plasticization. To investigate biodegradability, a two-step enzymatic degradation was performed using proteinase K and then cellulase. The copolymers with DSAcyl values below 1.3 exhibited enzymatic biodegradability with weight losses in the range 15.2%–34.6% (cf. 58.4% for polylactide).

Determination of the degree of substitution of cellulose esters via ATR‐FTIR spectroscopy

AbstractCellulose derivatives are promising bio‐based polymeric materials with possible applications ranging from thickening agents and stabilizers to optical films. The precise determination of their degree of substitution (DS) is crucial, as the DS substantially influences the material properties of such cellulose derivatives. Herein, the applicability of attenuated total reflection‐Fourier transform infrared for DS determination of cellulose esters was investigated. Sixteen cellulose acetates with DS ranging from 0.41 to 2.99 were synthesized and three acetyl group‐specific vibrational signals were evaluated quantitatively in reference to the cellulose anhydroglucose unit vibration ν(CO)AGU. A non‐linear correlation for the absorbance intensity with the DS was observed and the data was fitted based on a newly developed model with correlation coefficients R2 between 0.958 and 0.998, depending on the evaluated signal. This DS determination method is simple and efficient, since it does not need any prederivatization or extensive sample preparation and can furthermore be applied to non‐soluble samples. In order to widen the scope, eight cellulose butyrates, six cellulose laurates and six cellulose benzoates with different DS were synthesized and the DS determination method could be analogously applied to these cellulose esters, but a separate calibration for the different esters was found to be necessary.

DESTRUCTION OF POLYMERCEMENT PLASTER COATING DURING OPERATION OF WALL STRUCTURE

The disadvantage of limesand, limecement and cementlime plaster mortars is the intensive formation of cracks during hardening and operation, which leads to rapid destruction of the plaster coating, its detachment from the masonry, which causes increased humidity and loss of heat through it, as well as reducing the service life of the wall structure.The main reason for this is choosing the components of the mixture and their quantity without taking into account the processes occurring during curing of the coating and its "work" as part of the wall structure during operation.To solve the problem, the wall structure should be considered as a system that includes a plaster coating associated with the masonry through the contact area. The composition of the soluble mixture must be prescribed taking into account the processes occurring during its hardening and operation of the wall structure, the stresses that occur in it. It is necessary to choose the components of the mixture and their quantity, so as to ensure the reduction of stresses in the plaster coating and its contact zone with the masonry, to values, less than destructive. This will increase the service life of the coating and wall construction.Since the properties of polymercement plaster mortar are determined by its composition and structure, to achieve these goals, the possibility of managing them by purposeful selection of components of the soluble mixture was analyzed. For this purpose, redispersible polymer powders (RPP), polymer fiber, cellulose esters, and a fine filler with a low modulus of elasticity were used.Studies have shown that their use has changed the nature of the destruction, reduced the number of cracks formed during the hardening of the plaster mortar, slowed down their development and increased the service life of plaster mortar and the wall structure.

Permeation Properties of Water Vapor through Graphene Oxide/Polymer Substrate Composite Membranes.

Graphene oxide (GO) has attracted attention as an excellent membrane material for water treatment and desalination owing to its high mechanical strength, hydrophilicity, and permeability. In this study, composite membranes were prepared by coating GO on various polymeric porous substrates (polyethersulfone, cellulose ester, and polytetrafluoroethylene) using suction filtration and casting methods. The composite membranes were used for dehumidification, that is, water vapor separation in the gas phase. GO layers were successfully prepared via filtration rather than casting, irrespective of the type of polymeric substrate used. The dehumidification composite membranes with a GO layer thickness of less than 100 nm showed a water permeance greater than 1.0 × 10-6 mol/(m2 s Pa) and a H2O/N2 separation factor higher than 104 at 25 °C and 90-100% humidity. The GO composite membranes were fabricated in a reproducible manner and showed stable performance as a function of time. Furthermore, the membranes maintained high permeance and selectivity at 80°C, indicating that it is useful as a water vapor separation membrane.

Efficient Conversion of Cellulose to Thermoplastics by Mechanochemical Esterification

Despite the melting processibility of cellulose is of great importance to convert this abundant biomass to various products, the efficient and sustainable preparation of a thermoplastic cellulose material remains a challenge. Herein, we report a novel one-step ball-milling mechanochemistry method for efficiently converting cellulose to melt-processable cellulose stearates (SCEs) without sacrificing excess reagents. By adjusting the reaction conditions, a series of SCEs with degrees of substitution (DS) ranging from 1.30 to 2.37 are synthesized. Besides, the relationship between DS and the thermoplasticity of SCEs is well investigated. The obtained SCEs with DS beyond 1.62 show favorable thermoplasticity, which can be processed into homogeneous films with a maximum tensile strength of 12.4 MPa and an elastic modulus of 353.6 MPa by a conventional hot-pressing technique (160 °C, 10 MPa). Moreover, this method is universally used for achieving various thermoplastic fatty acid cellulose esters with different numbers of carbons (10–18) in side chains. Due to its high efficiency and sustainability, this approach holds great potential for the large-scale fabrication of thermoplastic cellulose-based materials.

Preparation of Bio-Foam Material from Steam-Exploded Corn Straw by In Situ Esterification Modification.

In this work, we engineered a corn-straw-based bio-foam material under the inspiration of the intrinsic morphology of the corn stem. The explosion pretreatment was applied to obtain a fibrillated cellulose starting material rich in lignin. The in situ esterification of cellulose was adopted to improve the cross-linking network of the as-developed foam bio-material. The esterification of lignin was observed in the same procedure, which provides a better cross-linking interaction. The esterified corn-straw-derived bio-foam material showed excellent elastic resilience performance with an elastic recovery ratio of 83% and an elastic modulus of 20 kPa. Meanwhile, with surface modification by hexachlorocyclotriphosphazene-functionalized lignin as the flame retardant (Lig-HCCP), the as-obtained bio-foam material demonstrated quite a good flame retardancy (with 27.3% of the LOI), as well as a heat insulation property. The corn-straw-derived bio-foam material is prospected to be a potential substitution packaging material for widely used petroleum-derived products. This work provides a new value-added application of the abundant agricultural straw biomass resources.

Copper hydroxide nanowires assisted molecule enrichment for highly sensitive SERS detection

Surface-enhanced Raman scattering (SERS) has been recognized as one of the most powerful spectroscopic tools for molecular detection. In the past decades, Hotspots engineering have promoted the improvement of SERS performance. Recently, molecular enrichment has proven to be another effective approach to improve SERS performance. In this work, we propose a concept of multiple filtration to increase the amount of analytical molecules, thus achieving molecular enrichment for ultra-low concentration detection. The approach combined the high Raman enhancement effect of Ag nanostructures and the multiple filtration capability of copper hydroxide nanowires (CHNs), making Ag/CHNs/Mixed cellulose esters (Ag/CHNs/MCE) complex highly sensitive SERS substrates by effectively concentrating analytical molecules in close proximity to the electromagnetic fields at the SERS-active metal surface. Using this enrichment strategy, the sensitivity of SERS is remarkably improved, and the detection limits of Rhodamine 6G and crystal violet are down to 1 × 10−13 and 1 × 10−11 M, respectively. This enrichment strategy is very robust and easy to implement, and it can potentially be exploited in various plasmonic-based molecule detection and identification techniques.

Single-Piece Membrane Supercapacitor with Exceptional Areal/Volumetric Capacitance via Double-Face Print of Electrode/Electrolyte Active Ink.

Single-piece flexible supercapacitors (FSCs) have light and ultrathin superiorities, thereby having great potential in portable/wearable electronics. However, all the available single-piece FSCs are fabricated by in situ growth routes, which are incompatible with large-scale technology. This work designs a carboxymethyl cellulose/phytic acid/polyaniline ink, incorporating electrode with electrolyte active compositions. Based on the electrode/electrolyte active ink, a double-face print technique on mixed cellulose ester and nylon membranes to fabricate single-piece membrane-FSCs, where both sides of membranes can be utilized well, is proposed. Consequently, one FSC is measured to be only ≈0.785 cm2 in area, ≈0.021g in weight, and ≈200µm in thickness, while it has exceptional areal and volumetric capacitances up to 757 mF cm-2 and 37.8 F cm-3 , respectively, based on the entire device. It also exhibits high flexibility with a capacitance retention of 98% after 2000 bend cycles from 0° to 180°. The state-of-the-art FSCs are expected to have exciting prospects in portable/wearable electronics, smart reading, and flexible displays. The preparation strategy renders the massive production of large-area and mini-size arrayed FSCs, and also the "do-it-yourself" or homemade preparation, which adds more interest and designability for general users.

Cellulose esterification with carboxylic acid in deep eutectic solvent pretreatment inhibits enzymatic hydrolysis

Avicel cellulose was pretreated using two commonly used carboxylic acid-based deep eutectic solvents, i.e., choline chloride-lactic acid and choline chloride-formic acid. The pretreatment process resulted in the formation of cellulose esters with lactic acid and formic acid, which was confirmed by infrared and nuclear magnetic resonance spectra. Surprisingly, the esterified cellulose led to a significant decrease in the 48-h enzymatic glucose yield (≥75%) compared to raw Avicel cellulose. Analysis of changes in cellulose properties caused by pretreatment, including crystallinity, degree of polymerization, particle size and cellulose accessibility, contradicted the observed decline in enzymatic cellulose hydrolysis. However, removing the ester groups through saponification largely recovered the reduction in cellulose conversion. The decreased enzymatic cellulose hydrolysis by esterification may be attributed to changes in the interaction between cellulose-binding domain of cellulase and cellulose. These findings provide valuable insights into improving the saccharification of lignocellulosic biomass pretreated by carboxylic acid-based DESs.

Single particle ICP-MS combined with filtration membrane for accurate determination of silver nanoparticles in the real aqueous environment.

This work presents the role of commercial microfiltration membranes combined with single particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) in removing environmental matrix interference for model silver nanoparticles (AgNPs) determination. The filters with different pore sizes (0.22μm, 0.45μm, 0.8μm) and materials (mixed cellulose ester, polyether sulfone, and nylon) were investigated to acquire the recovery of particle concentration and size of AgNPs spiked into different real aqueous solutions, including ultrapure water, tap water, surface water, and sewage effluent. The maximum recovery of nanoparticle concentration was 70.2% through the 0.8μm polyether sulfone membrane. The heated filters were able to improve the recovery of AgNPs particle concentration in the real aqueous environment. Hence, the pretreatment method by SP-ICP-MS combined with filtration membrane was simple, fast, and low-cost to quantify AgNPs in natural water environments.

Design of hybrid g-C3N4/GO/MCE photocatalytic membranes with enhanced separation performance under visible-light irradiation

Photocatalytic membranes with concurrent catalytic oxidation and separating functions possess promising potentials for the degradation of organic pollutants in wastewater treatment. Herein, we designed a hybrid photocatalytic membrane (viz., g-C3N4/GO/MCE) by vacuum-filtration-assisted assembling method, consisting of graphitic carbon nitride (g-C3N4) nanosheets as a top layer, graphene oxide (GO) nanosheets as an interlayer, and commercial mixed cellulose ester (MCE) as a substrate layer. The microstructures, chemical compositions, and physicochemical properties of the designed g-C3N4/GO/MCE membranes were systematically characterized by a series of characterization techniques. Particularly, photocatalysis-filtration reactor cells were designed for the evaluation of the simultaneous separation and photocatalytic degradation performance in a single unit using both organic dyes and antibiotics as modeling pollutants in wastewater. Four parameters were adopted to represent the integrated photocatalysis-filtration performance of our designed photocatalytic membranes, including permeance (P), rejection (R’, filtration alone), removal (R, combined photocatalysis-filtration under light-irradiation), and degradation rate (D). The hybrid membranes showed superior permeance and solute removal under visible-light irradiation (300 W, λ > 420 nm), in which the permeance was 20% higher than that of no-irradiation conditions. In addition, 10 consecutive cycling tests and light-on/off cycles of the as-prepared g-C3N4/GO/MCE membrane toward RhB showed quite stable permeance in the range of 268.9 to 352.9 L h−1 m−2 bar−1, and the removal was maintained in the range of 88.4% to 95.4%, indicating excellent long-term stability. Remarkably, it also exhibited good removal performance of antibiotics (e.g., ofloxacin, norfloxacin, sulfamethoxazole, erythromycin, and roxithromycin). Accordingly, the designed hybrid g-C3N4/GO/MCE photocatalytic membranes with excellent photocatalytic activity and photocatalysis-filtration performance are promising for wastewater treatment and water purification applications.

Microplastic ingestion by common terns (Sterna hirundo) and their prey during the non-breeding season

Current evidence demonstrates the presence and persistence of microplastics in the marine food web. Seabirds are predators in marine ecosystems and are highly exposed to marine plastic debris through the food. The aim of this work was to examine the presence of microplastics in a long-distance migratory seabird, the Common tern (Sterna hirundo) (n = 10), and in their prey (n = 53) during the non-breeding season. The study was conducted in Punta Rasa, Bahía Samborombón, province of Buenos Aires, which is an important resting and feeding location for migratory seabirds and shorebirds in South America. Microplastics were found in all the birds examined. The occurrence of microplastics in the gastrointestinal tract (GIT) of Common terns (n = 82) was higher than in regurgitated prey (RP) (n = 28), which is likely reflecting trophic transfer process. Almost all microplastics found were fibers and only 3 were fragments. Microplastics were sorted by color; transparent, black and blue-colored fibers were the most abundant plastic types. Characterization of the polymer type by Fourier Transform Infrared Spectrometry (FTIR) revealed that cellulose ester plastics, polyethylene terephtalate, polyacrylonitrile and polypropylene were the most abundant types found in both the gastrointestinal tract and prey. Our results highlight the high levels of ingested microplastics in Common terns and in their prey, and reflect a concern in this important location for migratory seabirds.

A comparative study on environmental surveillance of enterovirus: Using a two-phase separation method and a filtration method with a mixed cellulose ester (MCE) membrane

This study aimed to compare the sensitivity of two-phase separation and the filtration method using a mixed cellulose ester (MCE) membrane to detect enteroviruses in sewage samples. From December 2015 to July 2016, four domestic sewage samples (1 L/sample) were collected monthly from the Guangzhou Liede Sewage Treatment Plant, and each sewage sample was divided into two aliquots (500 mL). The sewage sample was concentrated using the two-phase separation and the filtration method using an MCE membrane, and the treated solutions were inoculated into cells for enterovirus isolation. Polymerase chain reaction amplification, VP1 sequencing, and enterovirus molecular typing were performed on the positive isolates. The detection rates of poliovirus (PV) and non-polio enterovirus (NPEV) obtained using the filtration method using an MCE membrane were higher than those using the two-phase separation method. McNemar's test showed that the detection rates of PV, NPEV, type 1 Sabin-like (SL1), type 2 Sabin-like (SL2), and type 3 Sabin-like (SL3) strain were not statistically significant (P > 0.05). In Guangdong Province, China, the detection rates for PV and NPEV were 53.13% and 62.50% (20/32), respectively. Twenty-seven PVs were isolated, three highly variable strains of the type 1 vaccine, with seven nucleotide substitutions in the VP1 region, compared with the type 1 Sabin strains. Eighty-seven strains of NPEV were isolated and nine serotypes were identified, among which coxsackievirus B3 (CVB3), echovirus 6(E6), and echovirus 11(E11) were the dominant strains. The filtration method using an MCE membrane is more sensitive than two-phase separation and can be used as a robust, sensitive, and cost-effective method to isolate enteroviruses from sewage.