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The most common reverse osmosis (RO) membranes that achieved economic water desalination applications are made of cellulose acetate (CA). Cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) have been blended with CA as innovative combinations to produce RO membranes through phase inversion technique. The relation between membranes compositions, structure, morphology, hydrophilicity and applicability were examined. Scanning electron microscope and Fourier transform infrared were used to evaluate the microstructure of these membranes. Hydrophilicity, strength, salt rejection and flow permeates were tested using a cross-flow reverse osmosis system and contact angle calculations. The contact angle measurements showed an increase from 56° for CA membrane to 71° for CAP membrane and 74° for CAB membrane. The hydro-phobicity of such membranes increased as CAP and CAB loadings increased. The salt rejection of pristine RO membranes increased from 93.2% with permeate of 1.4 L/m2 h for CA membrane to 96.8% with permeate of 1.07 L/m2 h for CAB membrane and 97.8% with permeate of 18.62 L/m2hr for CAP membrane. The salt rejection of supported membranes onto a nonwoven polyester fabric decreased from 92.8% with permeate of 3.78 L/m2 h for CA/0.5 wt% CAP to 91.4% with permeate of 6.05 L/m2 h for CA/0.5 wt% CAB and 88.5% with permeate of 5.84 L/m2 h for CA/0.1 wt% CAP/0.1 wt% CAB.

Xu, P. and Na, N., 2020. Study on antibacterial properties of cellulose acetate seawater desalination reverse-osmosis membrane with graphene oxide. In: Hu, C. and Cai, M. (eds.), Geoinformatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 246–251. Coconut Creek (Florida), ISSN 0749-0208. In this study, an antibacterial mixed-matrix reverse-osmosis membrane was prepared by adding graphene oxide (GO) through interfacial polymerization on the surface of a cellulose acetate (CA) reverse-osmosis (RO) membrane. The properties and structure of a GO-CA-RO membrane were analyzed by infrared spectrometry and Raman spectrometry, and the antibacterial properties of the GO-CA-RO membrane were tested. The relative inhibition rates of modified membrane products on Escherichia coli and Staphylococcus aureus were 75.93% and 79.98%, respectively. The results showed that a GO-CA-RO membrane prepared by interfacial polymerization has a good antibacterial effect.

Vast amounts of electromagnetic waves are generated in modern society, which severely endanger human health and cause instrument disturbance. Furthermore, practical application of electromagnetic shielding polymer-based materials aspires to flame retardancy. Herein, cellulose acetate butyrate modified ammonium polyphosphate (CAPP) and phosphoramide flame retardant decorated short carbon fiber (MSCF) were synthesized separately and then simultaneously blended into thermoplastic polyurethane (TPU) to prepare a series of flame retardant TPU composites. Then, the multi-hierarchical flexible TPU/CAPP/MSCF composites were fabricated via our self-developed air-assisted thermocompression method. The results revealed that the TPU/CAPP/MSCF showed improved thermal stability. Moreover, the TPU/10CA/2.5F incorporated with 10.0 wt.% CAPP and 2.5 wt.% MSCF respectively exhibited 77.8% and 58.6% reduction in peak of heat release rate (PHRR) and total heat release (THR), compared to those of pure TPU. In addition, the TPU/10CA/2.5F passed the UL-94 V-0 rating test and achieved a higher limit oxygen index (LOI) (27.3%) than pure TPU (21.7%). In the case of electromagnetic interference shielding effectiveness (EMI SE), the TPU/10CA/10.0F-SW with 10 wt.% CAPP and 10 wt.% MSCF dispersed in the surface layer and Ti 3 C 2 T x MXene intercalated in the interlayer exhibited EMI SE of 43.8 dB in X band and 32.0 dB in K band. Summarily, synergistic effect between CAPP and MSCF together with scattered and multiply adsorbed effect of MSCF, MXene and CAPP was responsible for fire safety and EMI shielding property improvements. This work provides a fascinating strategy for fabricating multi-hierarchical flexible TPU composites with outstanding flame retardant and EMI shielding performances.

This study investigated the recycling of freshly-smoked cigarette butts (FCBs) and unsmoked cigarette filters (UCFs) into a cellulose acetate (CA) membrane. The both samples were prepared by means of a combination of seven cigarette brands, and the phase inversion method was used to recycle each sample into a membrane using N-methyl-2-pyrrolidone. The efficiency of the prepared membranes for the removal of chromium, cadmium, and lead from an aqueous solution in a forward osmosis reactor was investigated. The results showed that the both membranes had a smooth surface and macrovoids. The flux of the prepared membranes from the UCFs and FCBs recycling were 14.8 and 13.2 LMH, respectively. The porosity and reverse salt of the UCFs membrane were 61% and 3.5 gMH, while those for FCBs membrane were 58% and 3.9 gMH. The observed metal removal efficiency of the both membranes was in the range of 85 to 90%. However, increasing the concentration of metals up to five times caused a slight decrease in the removal efficiency (less than 5%).

Cellulose microspheres have a wide range of applications due to their unique properties and versatility. Various preparation methods have been explored to tailor these microspheres for specific applications. Among these methods, the acetate method using cellulose acetate is well known. However, replacement of the acetate group through the butyrate group significantly extends the variety of morphological properties. In the present work, microspheres based on cellulose acetate butyrate are being developed with modified characteristics in terms of particle size, porosity, surface morphology and the inner structure of the microspheres. While the inner structure of cellulose acetate microspheres is predominantly porous, microspheres prepared from cellulose acetate butyrate are mainly filled or contain several smaller microspheres. Carbon materials from cellulose acetate butyrate microspheres exhibit a high specific surface area of 567 m2 g−1, even without further activation. Activation processes can further increase the specific surface area, accompanied by an adaptation of the pore structure. The prepared carbons show promising results in symmetrical supercapacitors with aqueous 6 M KOH electrolytes. Activated carbons derived from cellulose acetate butyrate microspheres demonstrate an energy density of 12 Wh kg−1 at a power density of 0.9 kW kg−1.

Cellulose acetate butyrate is a biodegradable cellulose ester bioplastic produced from plentiful natural plant-based resources. Solvent-exchange-induced in situ gels are particularly promising for periodontitis therapy, as this dosage form allows for the direct delivery of high concentrations of antimicrobial agents to the localized periodontal pocket. This study developed an in situ gel for periodontitis treatment, incorporating a combination of metronidazole and doxycycline hyclate, with cellulose acetate butyrate serving as the matrix-forming agent. Consequently, assessments were conducted on the physicochemical properties, gel formation, drug permeation, drug release, morphological topography, and antimicrobial activities of the formulation. The formulation demonstrated an increased slope characteristic of Newtonian flow at higher bioplastic concentrations. The adequate polymer concentration facilitated swift phase inversion, resulting in robust, solid-like matrices. The mechanical characteristics of the transformed in situ gel typically exhibit an upward trend as the polymer concentration increased. The utilization of sodium fluorescein and Nile red as fluorescent probes effectively tracked the interfacial solvent–aqueous movement during the phase inversion of in situ gels, confirming that the cellulose acetate butyrate matrix delayed the solvent exchange process. The initial burst release of metronidazole and doxycycline hyclate was minimized, achieving a sustained release profile over 7 days in in situ gels containing 25% and 40% cellulose acetate butyrate, primarily governed by a diffusion-controlled release mechanism. Metronidazole showed higher permeation through the porcine buccal membrane, while doxycycline hyclate exhibited greater tissue accumulation, both influenced by polymer concentration. The more highly concentrated polymeric in situ gel formed a uniformly porous structure. Metronidazole and doxycycline hyclate-loaded in situ gels showed synergistic antibacterial effects against S. aureus and P. gingivalis. Over time, the more highly concentrated polymeric in situ gel showed superior retention of antibacterial efficacy due to its denser cellulose acetate butyrate matrix, which modulated drug release and enhanced synergistic effects, making it a promising injectable treatment for periodontitis, particularly against P. gingivalis.

M13 bacteriophages (phages) are used as very important tools in molecular biology, biotechnology and, nanotechnology. Many methods have been developed so far for the purification of these phages. However, it is important that phages retain their infecting properties, especially in biotechnological applications such as phage display technology. The most widely used is the PEG precipitation method, but it has some limitations such as impurities and reduced infectivity. To overcome them, we developed a new method for purification of M13 bacteriophages using syringe filters made of cellulose acetate membranes with a pore diameter of 0.22 µm. Phages were aggregated so that they could remain on the filters and for this purpose, the pH of the phage cultures was reduced to 3. The phage cultures were filtered and then the phages were recovered in tris-buffered saline (TBS) buffer (pH 10.5) by reversing the filter. The recovery rate was 250% higher than the standard PEG method. This new Faj-elek method offers an alternative to existing methods, allowing cheaper, easier and faster purification of M13 phages using syringe filters available in every research laboratory.

Cellulose acetate (CA), an organic ester, is a biobased polymer which exhibits good mechanical properties (e.g., high Young’s modulus and tensile strength). In recent decades, there has been significant work done to verify the thermal and thermomechanical behaviors of raw and plasticized cellulose acetate. In this study, the thermomechanical properties of plasticized cellulose acetate—especially its ββ-relaxation and activation energy—were investigated. The general thermal behavior was analyzed and compared with theoretical models. The study’s findings could be of special interest, due to the known ββ-relaxation dependency of some polymers regarding mechanical properties—which could also be the case for cellulose acetate. However, this would require further investigation. The concentration of the plasticizers—glycerol triacetate (GTA) and triethyl citrate (TEC)—used in CA ranged from 15 to 40 wt%. DMTA measurements at varying frequencies were performed, and the activation energies of each relaxation were assessed. Increasing plasticizer content first led to a shift in ββ-relaxation temperature to highervalues, then reached a maximum before declining again at higher concentrations. Furthermore, the activation energy of the ββ-relaxation constantly rose with increases in plasticizer content. The trend in the ββ-relaxation temperature of the plasticized CA could be interpreted as a change in the predominant phase of the overlapping ββ-relaxation of the CA itself and the αα′-relaxation of the plasticizer—which appears in the same temperature range. The plasticizer used (GTA) demonstrated a higher plasticization efficiency than TEC. The efficiencies of both plasticizers declined with increasing plasticizer content. Additionally, both plasticizers hit the saturation point (in CA) at the lowest studied concentration (15 wt%).

A series of waterborne polyurethane (WPU) dispersions were prepared by chain-extending a prepolymer made of polyester diol, isophorone diisocyanate, and dimethylol propionic acid using cellulose acetate butyrate (CAB). The particle size and viscosity of the WPU dispersion were measured. In addition, we investigated the effects of CAB on the thermal, mechanical, and optical properties of WPU films. The use of CAB effectively improved the crosslinking degree of the WPUs, increasing the thermal stability and water resistance of the corresponding films. In particular, CAB increased the tensile strength of the WPU films up to 67%, while maintaining their elongation at break unchanged. In addition, CAB improved the optical transmittance by reducing the microphase separation between the soft and hard segments of PU. The rough surface structure of the WPU films formed by CAB led to improved matting properties.

Cellulose acetate butyrate (CAB) is a possible candidate, being a raw material derived from renewable resources, to replace fossil-based materials. This is due to its thermoplastic properties and the relative ease with which it could be implemented within the existing industry. With a significant amount of variation in CAB on the market today, a knowledge gap has been identified regarding the understanding of the polymer structural arrangement in films. This relates to the underlying mechanisms that regulate CAB film material properties, insights that are important in product development. In this study, commercially available CAB was investigated with XRD, SEM, AFM, and TOPEM DSC in order to obtain physicochemical information related to its micro-structural features in solvent-cast films. The film-forming ability relates mostly to the number of hydroxyl groups, and the semi-crystallinity of the films depends on the type and position of the side groups along the cellulose backbone. The appearance of signs of possible cholesteric ordering in the films could be connected to higher amounts of hydroxyl groups along the backbone that disturb the helix arrangement, while the overall order was primarily related to the butyrate substitution and secondarily related to the molecular weight of the particular CAB studied. Cold crystallization was also observed in one CAB sample.