Search

Photocatalysis disinfection has great potential for irrigation water disinfection to improve fresh produce safety. Titanium dioxide (TiO2) nanoparticle (NP)-embedded cellulose acetate (CA) film has shown effectiveness against Escherichia coli (E. coli) O157:H7 in water. The current study evaluated the effect of natural water compounds on the photo-disinfection efficacy of TiO2 NP-embedded CA film. Humic acid, calcium carbonate (CaCO3), and kaolin clay solutions were prepared at four concentrations, respectively. When concentration increased from 0 to 20 ml/L, inactivation of E. coli O157:H7 in humic acid, CaCO3, and kaolin clay solutions decreased from 6 log to 5, 4, and 2 log CFU/ml, respectively after 3 h treatment. Turbidity, UVT-254, water hardness, total suspended solids (TSS), and total organic carbon (TOC) of the solutions were measured. UVT-254 and turbidity had the highest correlation with the inhibition effect of water compounds on photo-disinfection efficacy. A prediction equation was developed with UVT-254 and water hardness as independent variables to predict photo-disinfection efficacy in natural water. E. coli O157:H7 decreased by 1 and 2.5 log CFU/ml in unfiltered and filtered natural creek water samples after treatment. The results from this study showed promise in the use of TiO2 NP-embedded CA film to inactivate pathogens in natural water. HIGHLIGHTS Natural water compounds affect TiO2 photo-disinfection efficacy in different degrees.; UV transmittance and water hardness are important water quality parameters that can affect TiO2 photo-disinfection efficacy.; Prediction equation was developed to predict TiO2 photo-disinfection efficacy in natural water.; Filtration is an effective pre-treatment method for improving TiO2 photo-disinfection in natural water.

Phenoxy-substituted phthalocyanine zinc (PPcZn) was synthesized and used as a photosensitizer to prepare a variety of self-disinfecting films by incorporating it into a cellulose acetate (CA) film at various concentrations. The generation of singlet oxygen (1O2) from the films containing PPcZn irradiated with visible light was detected by a film containing 1,3-diphenylisobenzofuran (DPBF). The rate of 1O2 generation followed a pseudofirst-order kinetic model. Antiviral activity was confirmed under visible light irradiation using Bacteriophage Qβ. The film exhibited superior water resistance, photostability, mechanical strength, and sustained 1O2 production over 6 months under continuous exposure to room light. These data show the promise of this film in real-life applications as self-disinfecting surfaces. A transparent film with photoactive antiviral functions and minimal degradation over time was easily obtained by uniformly dispersing the phenoxy-substituted phthalocyanine zinc (PPcZn) in the cellulose acetate film. This film produced singlet oxygen (1O2) upon visible light irradiation, and the production capacity of 1O2 was maintained even when the film was exposed to indoor lighting for 6 months.

A new way of controllable releasing menthol with amorphous silica is reported for the first time. Porous silica adsorbed menthol in 373‐413 K and then was covered with cellulose acetate film to form a carrier‐embedded menthol. The sealed menthol would be released at elevated temperatures once the cover fractured. Here, the influence of temperature and nature of sorbent on the adsorption of menthol along with the covering manner were investigated carefully, and the thermal release of menthol was studied with headspace gas chromatography (HS‐GC) method. Silica adsorbed about 400 mg g⁻¹ of menthol at the optimal adsorption conditions and released most of them at about 473 K. Preliminary application in non‐combustible cigarette proven the feasibility of thermal release of menthol with the covered silica carrier.

The surface of cellulose acetate (CA) films has been modified by gas–liquid fluorination. The treatment has been carried out with a fluorinating mixture (10 vol % F2 + N2) in a perfluorodecalin medium in a flow reactor for 30, 60, and 120 min. Film samples have been studied using X-ray diffraction and IR spectroscopy. It has been shown that the general appearance and position of peaks in the diffraction patterns of the initial and fluorinated CA samples are almost the same, indicating the absence of a significant effect of treatment on the phase composition of the film samples. On the contrary, according to IR data, there is an increase in the concentration of fluorine-containing and hydroxyl groups in the fluorinated CA layer. SEM images of cross sections of fluorinated films have confirmed their layered structure. The transport parameters of the films with respect to He, H2, O2, CO2, and CH4 have been also determined experimentally. The gas permeability has been found to monotonically decrease with an increase in the fluorination time and to increase with an increase in the size of the penetrant molecule. Direct fluorination also leads to an increase in O2/N2, CO2/CH4, N2/CH4, He/CH4, H2/CH4, and He/H2 ideal permselectivities compared to those of the unmodified cellulose acetate film. The data points for fluorinated CA films on the Robeson plots for these gas pairs approach the 1991 upper bound, whereas those for the virgin polymer are located in the middle of the plots.

A facile one− step method to fabricate acetylated cellulose nanocrystals (ACNCs) was developed by using mixed sulfuric acid and acetic acid hydrolysis. It could be demonstrated that the esterification of surface hydroxyl groups took place simultaneously with hydrolysis of amorphous regions of cellulose, which was confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectra (FT − IR) and X − ray diffraction (XRD) measurement. The as − prepared ACNCs exhibited typical rod − like morphology with diameter and length of 12 − 18 and 191 − 234 nm, respectively. All − cellulose nanocomposite films were subsequently produced by introducing ACNCs into cellulose acetate (CA) matrix through solution casting technique. The mechanical performance of nanocomposites was significantly enhanced due to the uniform dispersion of ACNCs and favorable CA − ACNC interface. The results showed that the tensile strength, Young’s modulus and elongation at break of nanocomposite film were increased by 78%, 58% and 68%, respectively, with the introduction of 5% ACNCs. Moreover, the nanocomposite films could retain good optical transparency. These results indicated ACNCs have a great potential to be used as reinforcing filler in polymer matrices for extending their industrial applications.

HighlightsPhoto-disinfection using TiO2 NP-embedded CA film showed great potential.TiO2 loading, water depth, and light intensity affected TiO2 photo-disinfection.Bacterial reduction can be predicted based on water depth and light intensity.Durability of the TiO2 NP-embedded CA film has been demonstrated.Abstract. Photocatalysis disinfection has great potential for food and water safety applications. TiO2 NP-embedded cellulose acetate (CA) film has shown effectiveness in inactivating Escherichia coli (E. coli) O157:H7 in water. This study evaluated the effect of several operational parameters such as TiO2 load, light intensity, and water depth on photo-disinfection efficacy of TiO2 NP-embedded CA film. Effect of TiO2 load on photocatalysis disinfection efficacy was investigated by assessing the disinfection rate of the films at different TiO2 levels in inoculated water at a weak UV-A light intensity. The individual and interaction effects of light intensity and water depth on photocatalysis disinfection were evaluated using the response surface methodology (RSM). Based on a central composite design, 13 runs of experiments were conducted with the combination of the two factors at three levels. The effect of film size on photo-disinfection efficacy was also investigated. Results showed that CA film with a TiO2 load of 0.82 mg/cm2 yielded the highest disinfection rate. An empirical model was established to predict the effect of light intensity and water depth on bacterial reduction with a high coefficient of determination (R2 = 0.98). An increased water depth or a decreased light intensity reduced photo-inactivation efficacy. A 5 log reduction was achieved during a 3-h treatment at a light intensity of 1 mW/cm2 and water depth at 1.6 cm. The photo-disinfection efficacy of the film was not significantly (p>0.05) affected by film size. The CA film was able to maintain antimicrobial efficacy after four repeated uses. Results from this study demonstrated that UV-A assisted photo-disinfection using TiO2 NP-embedded CA film has great potential to inactivate pathogens in water. Keywords: Cellulose Acetate, E. coli O157:H7, Photocatalysis, TiO2 nanoparticles, Water Treatment.

With the growing demand for fuel and simultaneous pollution caused by the use of traditional fuel sources, the quest for clean energy source is the biggest challenge forward. Thus, has given way to...

This paper presents the findings of an international online survey designed to better understand current practices and knowledge surrounding cellulose-based films showing signs of vinegar syndrome ...

The white spots known as microbubbles that are formed in cellulose acetate film, significantly affects the texture of the image. However, the formation of microbubbles and their corresponding microstructure are poorly understood. In this paper, cellulose acetate microfilm from the Republic of China (AD 1912–1949) collected in the Second Historical Archives of China was chosen as a prototype to investigate the causes of microbubble disease for the first time. A comparative study was conducted between the film samples with and without microbubbles. Herein, the microstructural analyses including optical and SEM microscopy were conducted. The crystals in the microbubbles proved to be triphenyl phosphate as identified by NMR spectroscopy and SEM–EDX. Comparative properties of the film substrate with and without microbubbles were measured by TG, XRD and FT-IR spectroscopy. The results show that formation of microbubbles was generally accompanied with the vinegar syndrome and was produced between the protective and emulsion layers with the different types of shapes along the closed structure (the diameter of ~ 0.1–2 mm). The formed microbubble was filled with plasticizer. Based on the above-mentioned results, the possible formation process of microbubble was proposed in the present study. The results can provide support for the cause of microbubbles and basis for the conservation of photographic films.

During the COVID-19 pandemic, personal protective equipment (PPE) has become crucial to protect humans from the transmission of the virus. The face shield is a simple and effective PPE to prevent the viral and bacterial contact. Since COVID-19 is known to be spread via respiratory droplets, the face shield has become increasingly important PPE. However, the common materials used in face shields are synthetic, environmentally unfriendly polymers, which cause an accumulation of plastic waste once disposed. Cellulose acetate (CA) can be used as an alternative for face shield films due to its ability to decompose safely in the environment; however, pristine CA cannot serve as an effective face shield due to its low hydrophobicity. In this research, the somewhat hydrophilic character of CA with a water contact angle of 55° is experimented on: hexamethyldisilazane (HMDS) is utilized to improve the hydrophobicity of CA up to a water contact angle of 77°. After the oxidization of the surface of CA via oxygen plasma, implementing HMDS shows a significant increase in hydrophobicity of the film.

In this study, cellulose acetate (CA)/cellulose nanofibril (CNF) film was prepared via solvent casting. CNF was used as reinforcement to increase tensile properties of CA film. CNF ratio was varied into 3, 5, and 10 phr (parts per hundred rubbers). Triacetin (TA) and triethyl citrate (TC) were used as two different eco-friendly plasticizers. Two different types of solvent, which are acetone and N-methyl-2-pyrrolidone (NMP), were also used. CA/CNF film was prepared by mixing CA and CNF in acetone or NMP with 10% concentration and stirred for 24 h. Then, the solution was cast in a polytetrafluoroethylene (PTFE) dish followed by solvent evaporation for 12 h at room temperature for acetone and 24 h at 80 °C in an oven dryer for NMP. The effect of solvent type, plasticizers type, and CNF amount on film properties was studied. Good dispersion in NMP was evident from the morphological study of fractured surface and visible light transmittance. The results showed that CNF has a better dispersion in NMP which leads to a significant increase in tensile strength and elastic modulus up to 38% and 65%, respectively, compared with those of neat CA. CNF addition up to 5 phr loading increased the mechanical properties of the film composites.

To preserve archive films of which the base material is composed of cellulose acetate, we carried out screening tests on various reagents. We selected sodium carbonate and sodium polyacryla...

Background Active packaging containing natural flavonoid has recently emerged due to its potential to inhibit the oxidation of foods by interacting with it and/or its surrounding environment, with the aim of counteracting oxidation reactions and extending the shelf-life of foods. The plant Spondias purpurea L. is widely found in northeastern Brazil and is known to contain bioactive flavonoids. The aim of this study was to obtain a flavonoid-rich fraction from the pulp of S. purpurea L. and incorporate it into the cellulose acetate film to obtain biodegradable films with antioxidant properties. Results The fractionation in SiO2 open-column chromatography of the S. purpurea pulp crude extract furnished an antioxidant active fraction containing the flavonols quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside as the major compounds. This active fraction was incorporated (10, 20, and 30 g kg-1 ) into the substance produced with the casting method for cellulose acetate films. The films produced were characterized concerning mechanical properties, water vapor permeability (WVP) and antioxidant activity. Conclusion The incorporation of the active flavonoid fraction from S. purpurea in the cellulose acetate films decreases WVP and elongation at break, while it also increases antioxidant activity, tensile strength and elastic modulus. Thus, the S. purpurea pulps may be an alternative as a source of antioxidants to be used in cellulose acetate films. This article is protected by copyright. All rights reserved.

Microbubble disease observed in cellulose acetate microfilm is accompanied by the production of vinegar syndrome, which affects the image integrity. In the present study, samples of cellulose acetate microfilm with microbubble disease were selected to investigate potential treatment methods. Samples were sourced from the Republic of China (AD 1912-1949) microfilm collections held in the Second Historical Archives of China. A combination of optical microscopy and a stainless-steel needle was used to remove plasticizer exudation within microbubbles. The plasticizer was effectively removed by infiltrating butan-1-ol into the microbubble from a small hole made by the stainless-steel needle. SEM and confocal microscopy were used to study the morphology and roughness of the internal surface of the microbubbles. It was found that the blurry image could be attributed to light scattering from the rough surface. Ethyl cellulose was used to fill the interior of the microbubble to obtain a clearer image. To determine the protective potential of this filling material, the chemical and mechanical properties of coated film after dry heat, hygrothermal and UV accelerated ageing were measured. Based on the above-mentioned results, it is encouraging that a new microrepair method and its corresponding method are offered in film treatment work.

Multiple cellulose-derived platforms were designed for the immobilization of pristine/functionalized CeO2 nanoparticles with efficient photocatalytic activity under UV light. CeO2 nanoparticles were synthesized at two different pH values (pH = 6 and pH = 9) observing that those prepared at basic pH have better defined shapes and, by modifying their surface with silane moieties, the band gap values decreased from 3.27 eV to 2.89 eV. The synthesized CeO2 NPs were embedded in cellulose acetate matrix in various amounts and the achieved nanocomposites were tested as photocatalysts under UV irradiation in the photodegradation of hazardous pollutants, the optimal results being obtained at nanoparticle loading of 5 wt%. Also, the matrix type strongly influences the reaction pathway for 4–nitrophenol, from mineralization to photoreduction to 4-aminophenol. The cellulose acetate film containing functionalized CeO2 NPs was deacetylated under alkaline medium, to regenerate the cellulose structure, and subsequently oxidized using TEMPO mediated protocol. Experiments on 4–nitrophenol photodegradation, in the presence of oxidized cellulose bearing CeO2 NPs showed that this is completely converted to 4–aminophenol and proved the versatility of the proposed materials. Nanocomposites have good reusability results and the film containing silane-functionalized CeO2 NPs displayed encouraging efficiency as photocatalyst under visible light.

Cellulose nitrate transparent plastic film was used by photographers and movie filmmakers from its release in the 1880s to the 1950s. The storage of this material is a challenge for cultural institutions because of its instability and hazardous nature, as nitrate is highly flammable and deteriorates over time. Historically, cellulose acetate gradually began to replace cellulose nitrate as it is not flammable. Despite its non-flammable properties, leading to cellulose acetate being called ‘safety’ film, over time it became clear that it also deteriorates in hazardous ways. Identification of cellulose nitrate and cellulose acetate in collections is necessary for preservation and risk management to collections and humans. Both cellulose nitrate and cellulose acetate are found in gallery, library, archive and museum photographic collections. As a result, identification and management of this material might be the responsibility of curators, librarians, archivists, collection managers, registrars or conservators, depending on the institution staffing and structure. Currently, there is no single identification method readily available to heritage institutions that meets the requirements to identify and distinguish between cellulose nitrate and cellulose acetate reliably, non-destructively and rapidly. In this study samples from both the Sydney University Museums and Australian National Maritime Museum collections have been analysed using infrared total reflectance spectroscopy, a novel approach which demonstrates great potential for rapid and non-invasive identification particularly when combined with multivariate statistical analysis methods. Principal component analysis (PCA) allowed for non-subjective data mining and the development of a model which is hoped to be used in the future for predicting sample identification. After calculation of the PCA model, the novel application of the Parsimax orthogonal rotation method potentially provides a means of determining the level of chemical deterioration in the cellulose nitrate film.

Abstract In this study an optical cellulose fiber for water sensoring was prepared by using a sequential preparation strategy. The core of the fiber was prepared from dissolved cellulose, in [EMIM]OAc, which was dry–wet spun into water. The cladding layer on the cellulose core was produced by coating a layer of cellulose acetate, dissolved in acetone, using a filament coater. The chemical and optical properties of both regenerated cellulose and cellulose acetate were studied from cast films using ultraviolet–visible and Fourier-transform infrared spectroscopy measurements. Regenerated cellulose film was observed to absorb UV light, passing the visible light wavelengths. Cellulose acetate film was observed to pass the whole light wavelength range. The mechanical strength and topography of the prepared optical cellulose fiber were investigated through tensile testing and SEM imaging. The mechanical performance of the fiber was similar to previously reported values in the literature (tensile strength of 120 MPa). The prepared optical fiber guided light in the range of 500–1400 nm. The attenuation constant of the cellulose fiber was observed to be 6.3 dB/cm at 1300 nm. The use of prepared optical cellulose fiber in a water sensor application was demonstrated. When the fiber was placed in water, a clear attenuation in the light intensity was observed. The studied optical fiber could be used in sensor applications, in which easy modifiability and high thermal resistance are beneficial characteristics. Graphic abstract Coaxial cellulose acetate-regenerated cellulose fiber for transporting light in sensor optical fiber sensor applications.

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 × 10-3mmol/g.

In the present work thermal roll to roll nanoimprint lithography process of various thermoplastic films (polycarbonate, polymethyl methacrylate and cellulose acetate) has been studied. To study the effect of the imprinting parameters on the process, the fabrication process of two different micropillars geometries has been carried out by fixing the imprinting speed, and changing the imprinting temperature and pressure, while the morphological characterization of the obtained microstructured films has been performed. Moreover, hydrophobic properties of the films have been measured to characterize the functionality of the surfaces. Among the studied three polymers, polycarbonate film has shown the best performance for the imprinting of both micropillars geometries, whereas cellulose acetate film didn't fully replicate the smallest micropillars. Polycarbonate film composed of 60 μm pitch and 40 μm height pillars has shown a static water contact angle value of 138°.

Cellulose acetate films were impregnated with carvacrol using supercritical carbon dioxide. The supercritical impregnation process, conducted in a static regime at pressure of 21 MPa and temperature of 50°C, was optimized by variation in the processing time (30 and 120 min) and decompression rate (from 0.3 MPa/min to 36 MPa/min). Characterization of the obtained cellulose acetate films was performed by Atomic Force Microscopy and Differential Scanning Calorimetry. Effects of glycerol and carvacrol on the properties of the films were discussed. Release kinetics from the cellulose acetate film with 31.4% of carvacrol was investigated in a physiological saline solution. In addition, the Higuchi and Korsmeyer-Peppas release models fitted the carvacrol release curve well. Obtained cellulose acetate films impregnated with carvacrol can be of interest for the application in medicine as wound dressings considering their biocompatibility and biodegradability as well as their potential antimicrobial activity or in the food industry as an active food packaging. Filmovi acetata celuloze su impregnirani karvakrolom pomoću natkritičnog ugljenik(IV)-oksida. Proces natkritične impregnacije, izveden u statičkom režimu na pritisku 21 MPa i temperaturi 50°C, je optimizovan varijacijom procesnog vremena (30 i 120 min) i brzine dekompresije (od 0,3 MPa/min do 36 MPa/min). Karakterizacija dobijenih filmova acetata celuloze je izvedena pomoću mikroskopije atomskih sila i diferencijalne skenirajuće kalorimetrije. Efekat glicerola i karvakrola na karakteristike dobijenih filmova je objašnjen. Otpuštanje karvakrola iz filma koji je ima 31,4% primos impregnacije karvakrola je ispitano u fiziološkom rastvoru. Dodatno, Higuči i Korsmejer-Pepas modeli otpuštanja su dobro fitovali krivu otpuštanja karvakrola. Dobijeni filmovi acetata celuloze impregnirani karvakrolom mogu biti značajni za primenu u medicini za previjanje rana uzimajući u obzir njihovu biokompatibilnost i biodegradabilnost kao i potencijalno antimikrobno dejstvo ili u industriji hrane kao aktivno pakovanje.

Active packagings (antimicrobial) control microbial contamination and reduce the need for preservatives added directly to food. Their active character can be obtained by adding essential oils (EO), which are natural extracts with antimicrobial properties. This work aimed to produce active films of cellulose acetate by incorporation of pink pepper EO, evaluating this action by diffusion in solid medium (agar), dispersion in liquid medium (broth), volatilization (micro-atmosphere), and in situ (sliced mozzarella cheese) against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium. The concentrations of 2, 4 and 6% of EO added to the films made them active against L. monocytogenes and S. aureus in all evaluated media. Escherichia coli was sensitive in liquid medium, micro-atmosphere and in situ, while S. Typhimurium showed sensitivity to the films in liquid medium and in situ. The in situ tests demonstrated that the affinity between nonpolar molecules of EO and the lipid components of cheese allows the EO of the polymer to migrate to food, indicating favorable characteristics for its use as active packaging, by direct contact.

An optical film with high optical anisotropy was prepared by the stretching of a cellulose acetate film and the consequential orienting of a retardation-enhancing additive. The change in retardation in response to moisture absorption was explored and it was found that the degree of the retardation variation is strongly related to the stretching temperature. Stress generated by the stretching and its relaxation was systematically investigated to elucidate the effect of stretching temperature on the irreversible change in retardation upon moisture absorption. The results show that the magnitude of releasable stress plays an important role in controlling changes in optical properties. In addition, the difference in the deformation behavior between glassy and rubbery states should be taken into account in the development of a moisture-resistant optical film. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1470–1478

Background: The routine approach to delve into the organization of mineralized and nonmineralized structures of teeth is by studying whole tooth or slices of it by making thin section which requires laborious grinding or employing specialized equipment and also leads to specimen wastage. Peels hitherto utilized for fossil studies hold promise in overcoming the aforesaid shortcomings. Although the acetate peel technique has been modified for the study of tooth structure, the field remains largely unexplored. Aim: The current study was taken up to explore the usefulness of cellulose acetate peels in reproducing microscopic structures of teeth as seen in routine ground sections and further if they could supplement or replace the same. Materials and Methods: Extracted human teeth were embedded in plaster blocks in longitudinal and transverse orientation, ground and polished with silicon carbide paper. Following etching, washing and drying, the polished surface was wet with acetone and precut cellulose acetate film was placed over it and allowed to dry. As the acetate polymer dissolved in acetone and subsequently re-polymerized after setting into the micro reliefs produced by tooth etching, it registered the microscopic tooth details on its surface. The peels were mounted and secured on a glass slide and subjected to routine light and phase contrast microscopy for observing captured details of the tooth structure. Results and Conclusion: Acetate peels successfully reproduced most of the microscopic tooth details which were better than those observed in ground tooth sections. Hence, this technique could be considered as a quick, durable and inexpensive alternative or supplement to routine thin ground sections of dental hard tissues.

The penetration of water into a cellulose acetate (CA) film with m-terphenyl (m-TP) as a waterproofing agent (WPA) was investigated in real time by coherent anti-Stokes Raman scattering (CARS) microspectroscopy. Owing to the WPA, the water penetration was significantly suppressed. It was manifested by a small spectral change in comparison with the CA films without m-TP. Moreover, the amplitude of the Raman band at 1600 cm−1 due to the OH bending mode, which is the marker band of water penetration, was significantly smaller. The present results indicate that m-TP has significant effects as a WPA for CA films on the water penetration process.

To address the industry's interest in finding novel biobased glues, the adhesive properties of the bacterial polysaccharide FucoPol were evaluated through shear bond strength tests. A FucoPol solution was used to bond different materials, namely, wood, glass, cardboard and cellulose acetate film. The shear strength was compared to that of the same adherends bonded with commercial synthetic glues. Wood-wood joints bonded with FucoPol formulation withstood 742.2±9.8kPa shear strength without detachment. FucoPol adhesive capacity for cardboard was comparable to that of the tested commercial glues (425±8.9kPa), yielding similar shear strength values (416.0±12.9kPa), while improved performance was shown for glass (115.1±26.2kPa) and cellulose acetate film (153.7±11.3kPa) comparing to the commercial glues (67.7-97.5kPa and 79.4-92.7kPa, respectively). This study demonstrates the adhesive properties of FucoPol, opening up the opportunity of using this bacterial polysaccharide for the development of new natural water-based glues, suitable to bond different materials.

The penetration process of water into a cellulose acetate film was traced in real time by coherent anti-Stokes Raman scattering (CARS) microspectroscopy. The Cdouble bond; length as m-dashO stretch mode was red-shifted due to hydrogen-bond formation. We also found that two Raman bands at 1605 cm−1 and 1665 cm−1 emerged only in the early stage of the water penetration process. Based on the combined analysis of the experimental and computational studies, these bands at 1605 cm−1 and 1665 cm−1 were assigned as the OH bend mode due to hydrogen-bonded penetrated water and hydrogen-bonded OH groups in pyranose rings, respectively.

This study aimed to investigate the properties of the films containing cellulose acetate and different amounts of polyethylene glycol 200 designed for controlled porosity osmotic pump systems. Polyethylene glycol 200 was used as a plasticizer and pore-forming agent and was incorporated into the cellulose acetate films at the varied concentrations. Water permeability through the films was determined based on the osmotic pump system using a device developed for this study. The film properties including polymer interaction, mechanical properties, swelling properties, thickness, porosity, polarity and morphology of the films were investigated. The amount of polyethylene glycol 200 had an effect on the film strength and the water permeability, increasing the amount resulted in greater water permeability. Scanning electron microscopy images showed that there was an increase in the number of pores in the films as the polyethylene glycol 200 content was increased. Moreover, the thickness of the films also affected the water permeation rate, increasing the thickness led to a decrease in the water permeability. This study reported additional knowledge regarding the properties and characteristics of cellulose acetate films with different proportions of polyethylene glycol 200. This could be applied to the development of a pharmaceutical formulation especially a controlled porosity osmotic pump system in the future.

The construction, operation, and performance characteristics of a compact dualwavelength, solid-state photometer and fiber-optic probe for use with absorbance based thin-film sensors are described. The instrument has been specifically designed for field deployment and uses low-cost components while maintaining a precision and accuracy comparable to fluorescence-based laboratory sensors. The computer-controlled photometer employs red and green light-emitting diodes (LEDs) as fixed-wavelength light sources and silicon photodiodes as detectors, and it has no moving parts. Graded refractive index lenses control light propagation through a beam splitter in the photometer and through the fiber-optic probe. The beamsplitter directs light simultaneously on to a sample and a reference detector in a doublebeam in-space mode which compensates for fluctuations in the outputs of the LEDs. A chemically modified polymeric film is mounted on the fiber probe and serves as an optical pH sensor. The previously described sensing film is constructed by the immobilization of the diprotic acid-base indicator Congo Red at a base-hydrolyzed cellulose acetate film and responds to changes in pH between 0 and 4.2. An absorbance-based internal calibration scheme, which takes advantage of the optical properties of each of the reactive forms of the immobilized indicator, is presented. The potential capability of this instrumentation, based on its small size and minimal need for calibration, to function as a durable low-maintenance pH sensor for on-site deployment in environmental monitoring applications, is discussed.

The effective and reusable photocatalyst film based on metal @metal organic framework@cellulose acetate [metal (Ag & Pd)@MIL-125-NH2@CA] was systematically studied. Nano-silver was grown over the crystalline disc of MIL-125-NH2 within CA film, while, self-assembly of crystalline trees like the structure of Pd)@MIL-125-NH2 was observed inside CA matrix. The calculated band gap was diminished from 2.53 eV to 2.38–1.99 eV after doping of metal (Ag & Pd) within MIL-125-NH2@CA film. Compared to MIL-125-NH2@CA; metal (Ag & Pd)@MIL-125-NH2@CA film showed a considerably higher photocatalytic reduction of nitro-aromatics in visible light. After 60 min, 80.6–93.5 % of 2-nitrophenol was photoreduced when metal (Ag & Pd)@MIL-125-NH2@CA film was used. After 5 recycles, the photoreduction percentage of 2-nitrophenol was lowered to 54.4–62.0. The produced metal@MIL-125-NH2@CA films showed an effective photocatalytic reduction of nitro-aromatics in the visible light, reflecting their promising performance in preparation of intermediates useful in many industrial products.

The studies on photocatalytic disinfection of water contaminated with Escherichia coli using Ag core and TiO2 shell (Ag@TiO2) nanoparticles under UV irradiation showed that these nanoparticles are very efficient in water disinfection both in their free and immobilised form. Complete disinfection of 40 × 10(8) CFU/mL could be achieved in 60 min with 0.4 g/L catalyst loading and in 35 min with 1 g/L catalyst loading. Ag@TiO2 nanoparticles were found to be superior to TiO2 nanoparticles in photocatalytic disinfection of water. Kinetics of disinfection followed Chick's law, and the pseudo-first-order rate constant was 0.0168 min(-1) for a catalyst loading of 0.1 g/L. Disinfection of water and degradation of endotoxins (harmful disinfection residual) occurred simultaneously during photocatalysis thereby making the treated water safe for use. Endotoxin degradation showed a shifting order of kinetics. The rate of photocatalysis with nanoparticles immobilised in cellulose acetate film was marginally lower as compared to that of free nanoparticles. Negligible Ag ion leakage and re-growth of cells post-photo-catalytic treatment of water confirmed that complete disintegration of E. coli occurred during photocatalysis making the treated water safe for use. Therefore, Ag@TiO2 nanoparticles have a potential for large-scale application in drinking water treatment plants and household purification units.

Cellulose nitrate was widely used as a film base for photography, cinematography, and radiography in the first half of the twentieth century. Its stability is inherently poor and subject to environmental storage conditions. The risk of fire and the cross-infection effect on the cellulose acetate film stored at the same location necessitate that cellulose nitrate is identified within collections and stored separately. Not only medical archives, but also museums using radiography in their research may hold a sizeable amount of historical X-ray films. The Natural History Museum, London has been using film for X-radiography since before World War II. This suggests that some of the X-ray materials in its collections have a cellulose nitrate rather than ‘safety’ (cellulose acetate or polyester) film base. X-ray sheets rarely contain information related to their composition so science-based identification methods must be used. We propose the determination of nitrogen content in the film by organic elemental anal...

The liquid crystal (LC) alignment behaviors of LC cells fabricated with cellulose acetate films were investigated. These polymer films exhibited good optical transparency in the visible light region (400–700 nm). For example, transmittance value (92%) of the cellulose acetate film onto glass substrate at 550 nm is better that (89%) of the polyimide (PI) film, the most commonly used LC alignment layers. These LC cells fabricated with the rubbed cellulose acetate films showed the homogeneous planar LC alignment with parallel direction with respect to the rubbing direction. The electro-optical characteristics of the LC cells made from the cellulose acetate films such as response time were as good as those fabricated from rubbed PI films.

Ag@TiO2 nanoparticles were synthesized by one pot synthesis method with postcalcination. These nanoparticles were tested for their photocatalytic efficacies in degradation of phenol both in free and immobilized forms under UV light irradiation through batch experiments. Ag@TiO2 nanoparticles were found to be the effective photocatalysts for degradation of phenol. The effects of factors such as pH, initial phenol concentration, and catalyst loading on phenol degradation were evaluated, and these factors were found to influence the process efficiency. The optimum values of these factors were determined to maximize the phenol degradation. The efficacy of the nanoparticles immobilized on cellulose acetate film was inferior to that of free nanoparticles in UV photocatalysis due to light penetration problem and diffusional limitations. The performance of fluidized bed photocatalytic reactor operated under batch with recycle mode was evaluated for UV photocatalysis with immobilized Ag@TiO2 nanoparticles. In the fluidized bed reactor, the percentage degradation of phenol was found to increase with the increase in catalyst loading.

In this study novel concept of osmotically controlled drug delivery system in the form of three layered sandwiched tablet (SOT) was introduced. The tablets were prepared and optimized by design of experiment method. Metoprolol succinate, an antihypertensive agent, was selected model drug. Modified Ishikawa diagram was used to understand critical parameters that might affect the final product. Sandwiched osmotic tablets were prepared by direct compression and coated with cellulose acetate film. The process and formulation parameters were initially screened by Plackett–Burman design and later optimized by Box Behnken design. From the tablets we evaluated hardness, friability, weight variation, weight gain, coating uniformity and in vitro drug release as critical quality attributes. The amount of sodium chloride, polyethylene oxide and hydroxypropyl methylcellulose were found to influence the drug release rate from SOT as evident from Plackett–Burman design. Further these factors were optimized to get extended drug release of 80 % or more in 20 h. Optimized formulation batches (BBD8 and BBD5) showed drug release of 79.62 ± 1.19 and 82.46 ± 0.45 % respectively in 20 h with diffusion controlled zero order drug release. The check point batch prepared showed drug release of 80.86 % in 20 h. The prepared osmotically controlled sandwiched tablet showed potential to control the drug release with zero order kinetics.

Highly uniform, flexible, and transparent electrodes based on in situ polymerization of PANi nanowires on nylon nanofiber-reinforced cellulose acetate thin film substrates were reported in this study. At first, the nylon nanofibers were electrospun followed by infiltration with cellulose acetate to get highly transparent substrate. Then PANi nanowires were grown uniformly on the transparent substrate by an in situ polymerization technique. The resulting thin films showed transparency from 39% to 82% and sheet resistivity between 188 and 8700 Ω/sq depending on the aniline monomer concentration. In addition, the transparent electrode exhibited outstanding toughness during bending cycles. Further, the transparent electrode showed excellent capacitive performance with specific capacitance of 402 F/g. These promising results highlight the importance of PANi nanowires and nylon reinforced cellulose acetate film as potential materials for optoelectronic devices.