Cast Films Research Articles

Preparation and Evaluation of Amorphous Solid Dispersions for Enhancing Luteolin's Solubility in Simulated Saliva.

Luteolin (LUT), a bioactive flavonoid, possesses various pharmacological properties, including antioxidant, antimicrobial, anti-allergic, cardio-protective, and anti-cancer activity. Among them, LUT's administration for the treatment of periodontal disease is very promising. However, its low water solubility magnifies the challenge of formulating LUT into an effective dosage form. In this vein, the aim of the present study examines the preparation of amorphous solid dispersions (ASD) for the solubility improvement of LUT in saliva. At first, the physicochemical properties of the active pharmaceutical ingredient (API) were studied before the selection of the most suitable ASD matrix/carrier. For this reason, six commonly used polymeric ASD matrix/carriers (namely, povidone, PVP; copovidone, coPVP; hydroxypropyl cellulose, HPC-SL; hydroxypropyl methyl cellulose acetate succinate, HPMC-AS; Eudragit® RS, Eud-RS; and Soluplus®, SOL) were screened via the film casting method, as to whether they could suspend the drug's recrystallization. The most promising matrix/carriers were then evaluated, based on their ability to inhibit LUT's precipitation after its solubilization, via the solvent shift method. Based on both screening methods, it was determined that PVP was the most promising matrix/carrier for the preparation of LUT's ASDs. Hence, in a further step, after the successful testing of components' miscibility, LUT-PVP ASDs were prepared via the solvent evaporation method. These systems (examined via powder X-ray diffractometry, pXRD) showed full API amorphization immediately after preparation and excellent physical stability (since they were stable after 3 months of storage). The study of LUT-PVP ASD's ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) spectra demonstrated strong H-bonds between the molecules of the drug and the matrix/carrier, while molecular dynamics (MD) simulations were able to shed light on these drug-matrix/carrier interactions, at a molecular level. Finally, in vitro dissolution studies in simulated saliva proved that the prepared ASDs were able to significantly enhance LUT's dissolution profile. Hence, according to findings of the present work, the preparation of LUT-ASDs utilizing PVP as the polymeric matrix/carrier is regarded as a highly promising technique for the improvement of API's solubility in the oral cavity.

Multifunctionally-doped PEDOT for organic electrochemical transistors

Organic Electrochemical Transistors (OECTs) are suitable for developing ultra-sensitive bioelectronic sensors. In the organic electrochemical transistors architecture, the source-drain channel is made of a conductive polymer film either cast from a formulated dispersion or electrodeposited from a monomer solution. The commercial poly(3,4-ethylenedioxidethiophene)/poly(styrene sulfonate) (PEDOT:PSS) water dispersion is the workhorse of organic bioelectronics for its high conductance, low impact and ease of processability. In this study, a hybrid organic electrochemical transistors channel fabrication strategy is presented, where electrochemical deposition of a PEDOT/X (with X indicating the counterion) is performed on a dispersion-cast PEDOT:PSS film. Six different counterions where used: X = PSS, Nafion, Hyaluronate, Dextran sulfate, Dexamethasone phosphate and tauroursodeoxycholic acid, each potentially endowing organic electrochemical transistors with additional functions such as ion exchange and pharmacological activity upon release of X. The PEDOT/X-PEDOT:PSS bilayers were characterized by means of electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and focused ion beam tomography combined with scanning electron microscopy (FIB-SEM). In addition, their respective organic electrochemical transistorss were characterized and compared to PEDOT:PSS organic electrochemical transistors. Our results show that the hybrid bilayer strategy is viable to fabricate multifunctional organic electrochemical transistorss with biologically-relevant function, thereby retaining the outstanding figures of merit of commercial PEDOT:PSS.

Unprecedented water permeation in nanostructured PVDF membranes prepared by unidirectional freezing and surface melting method

Phase inversion has played a vital role in membrane technology by offering the economic viability for producing polymeric membrane in quantity, and it allows for the development of wastewater treatment technologies with the membrane as a promising energy-saving separator. However, most existing phase inversion membranes suffer from low permeance, thus diminishing their advantages in the quest for more efficient and sustainable separation processes. Here, based on unidirectional freezing approach, we showcase a hierarchical porous membrane that outperforms the permeance of the phase inversion membranes without compromising the membranes’ separation capabilities. An unprecedented surface melting atop a frozen membrane cast film promotes the phase inversion in the water phase, which in turn constructs an additional separating layer on membrane surface. These membranes exhibit tuneable pores in the range between 9 and 50 nm and pure water permeation which is 16–25 times higher than that of an equivalent industry standard. Moreover, the synergy between freezing and melting enables a separate design of pore sizes from membrane both surfaces, leading to a dual-skin polymeric membrane showing enhanced functionality throughout its cross-section. With the enhanced efficiencies, these membranes have potential to positively contribute to the current water-energy nexus, by considerably improving the economic and technological viability of many water-treatment and filtration-based separation systems.

Processing optimization of PEDOT:PSS and PEDOT:PSS/Tween 80 films

The optimum processing conditions for PEDOT:PSS and PEDOT:PSS/Tween 80 cast films were investigated by considering film quality and resistivity. The thermal stabilities of these materials were found to strongly influence the accessible annealing temperatures, especially in the presence of the conductivity-enhancing agent Tween 80. The resistivities of PEDOT:PSS films with and without Tween 80 decreased by up to 85% with increases in both annealing temperature and time until a plateau was reached. In addition, thermal structural rearrangements of these polymers were the key driving factors that reduced resistivity, with water removal alone insufficient. Finally, the optimum processing conditions for PEDOT:PSS and PEDOT:PSS/Tween 80 films are detailed.

Antimicrobial Bilayer Film Based on Chitosan/Electrospun Zein Fiber Loaded with Jaboticaba Peel Extract for Food Packaging Applications.

This work focused on developing an active bilayer film based on natural extract. Thus, the jaboticaba peel extract (JPE) was produced and characterized and showed promising application as a natural additive in biopolymeric materials. The zein fiber and bilayer films were produced using a chitosan film (casting) and zein fiber (electrospinning), with and without JPE. All samples were evaluated according to thickness, solubility in water, water vapor permeability, and main diameter, and for these, zein fiber, chitosan/zein fiber, and chitosan/zein fiber + 3% JPE showed values of 0.19, 0.51, and 0.50 mm, 36.50, 12.96, and 27.38%, 4.48 × 10-9, 1.6 × 10-10, and 1.58 × 10-10 (g m-1 Pa-1 s-1), and 6.094, 4.685, and 3.620 μm, respectively. These results showed that the addition of a second layer improved the barrier properties of the material when compared to the monolayer zein fiber. The thermal stability analysis proved that the addition of JPE also improved this parameter and the interactions between the components of the zein fiber and bilayer films; additionally, the effective presence of JPE was shown through FTIR spectra. In the end, the active potential of the material was confirmed by antimicrobial analysis since the bilayer film with JPE showed inhibition halos against E. coli and S. aureus.

Eco-friendly preparation and characterization of bioplastic films made from marine fish-scale wastes.

Synthetic plastics are becoming hazardous wastes, posing a threat to environmental sustainable health; hence, they must be replaced with alternatives. This study aimed to prepare corn starch-based bioplastics using fish scale through film casting technique as an alternative to synthetic plastics. In this work, four types of bioplastic films (CSF, CSFSF1, CSFSF2, FSF) containing different percentages of fish-scale powder and corn starch were prepared. Physical and chemical properties such as texture, color, solubility in hot water, tensile strength, functional groups, and morphology of all the four types of the prepared bioplastics were analyzed. The mixture of fish-scale powder and corn starch powder in the ratio of 1:3 (CSFSF1) yielded the best results. Its average thickness is 0.0420 ± 0.001mm, water absorption range is 55-60%, tensile strength is 6.06 ± 0.05MPa, and thermal stability is 278.741°C. In the biodegradability test, degradation was noticed after 7days of treatment with organic waste. The degradation was confirmed by surface changes in the morphology and the development of Aspergillus sp. Corn starch film (CSF) exhibited the highest degradation (60%), while the fish-scales film (FSF) underwent the least degradation (28%). The produced bioplastics were prepared from eco-friendly, inexpensive, and natural materials. Thus, the present research has provided a viable alternative to synthetic plastics.

Effect of uniaxial stretching on the structural and dielectric properties of melt cast Nylon 11 films

AbstractIn this study, the effect of processing on the structural and dielectric properties of Nylon 11 melt cast film was studied. Capacitor grade thin films were cast using a film extruder and stretched uniaxially and real‐time mechano‐optical data were acquired at temperatures ranging from solid state all the way to partially molten state. These studies were supplemented with offline WAXS, SAXS, and DSC to develop a complete understanding of processing induced structural changes and their relation to dielectric properties. When stretched in the solid‐state, preferential crystalline and amorphous chain orientation levels increased as a function of strain while the long spacing remained constant due to lamellar slippage. Processing in the partially molten state led to the formation of new lamellae with larger long spacings. It was also observed that the dielectric properties of Nylon 11 were strongly dependent on the crystallinity and crystal phase, with higher crystallinity of the α′ phase giving higher electrical breakdown strength. When films were stretched to 3X solid and partially molten states, together with crystallinity, the breakdown strength is increased, while the dielectric constant and loss decrease. Since crystalline regions are stiffer, they form effective barriers to hot carriers, retarding the electric breakdown.

Facile synthesis of nanogranular PPy thin films for sensitive and selective detection of toxic NO gas

The pyrrole monomers have been synthesized by in situ oxidative polymerization and followed by the drop casting of polypyrrole thin films onto glass. The optimized PPy thin film for gas sensor showed the highest NO 2 sensitivity of 40.08 % at room temperature with a stable response even after 45 days with a retention of stability of around 86 %. The gas sensing results suggested that the nanogranular PPy sensor exhibited an excellent response toward NO 2 and also showed high sensitivity even at low concentrations up to 10 ppm. • Synthesis of pyrrole monomers by in situ oxidative polymerization for NO 2 gas sensor. • Achieve sensitivity of 40.08 % at room temperature with a stable response even after 45 days. • Selective sensing towards NO 2 within a wide range of concentrations from 10 to 100 ppm. • The sensor exhibits reliable long-term stability, reproducibility and reversibility. Nanogranular polypyrrole (PPy) have been synthesized by in-situ oxidative polymerization of pyrrole monomer followed by deposition of PPy thin films onto a glass substrate by drop casting method. The deposited thin films were characterized for their structural, morphological, compositional studies using x-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and x-ray photoelectron spectroscopic (XPS) studies. The XRD patterns revealed that the synthesized films are amorphous in nature. FE-SEM microscopic images exhibit agglomerated granular-like morphology of PPy thin films with high degree of roughness. The XRD patterns confirm the amorphous nature of PPy thin films. XPS analysis reveals the formation of PPy. The gas sensing properties of PPy thin film based gas sensor were studied in terms of sensitivity, response-recovery time, selectivity and stability by varying the concentration of nitrogen dioxide (NO 2 ) gas. The optimized PPy thin film gas sensor showed highest sensitivity of 40.08 % at room temperature with stable response even after 45 days with retention of stability around 86%. The gas sensing results suggested that nanogranular PPy sensor exhibited an excellent response toward NO 2 and also showed high sensitivity even at low concentrations upto 10 ppm level.

Harry Potter and the Other: Race, Justice, and Difference in the Wizarding World ed. by Sarah Park Dahlen and Ebony Elizabeth Thomas

Reviewed by: Harry Potter and the Other: Race, Justice, and Difference in the Wizarding World ed. by Sarah Park Dahlen and Ebony Elizabeth Thomas Emily Lauer (bio) Harry Potter and the Other: Race, Justice, and Difference in the Wizarding World. Edited by Sarah Park Dahlen and Ebony Elizabeth Thomas. University Press of Mississippi, 2022. The essay collection Harry Potter and the Other: Race, Justice, and Difference in the Wizarding World is a broad-ranging and necessary addition to the ever-evolving field of Harry Potter scholarship. As the editors mention in their introduction to the book, they were motivated by the need to explore "the contradiction that lies at the heart of the Potter series: an author and a world that make the tacit promise of fantastic escape for the marginalized, all while the author inscribes exclu sion and bigotry within the wizarding world—as well as with her public words" (9). The contributors to Harry Potter and the Other employ a breadth of approaches to the vast transmedia landscape of the world of Harry Potter. The collection ranges widely: from analysis of specific fan artists' race-bending illustrations of characters, to a pedagogical essay about how one professor of color uses the Potter series in a college composition course, to an examination of trans-exclusionary themes in the Harry Potter books predating Rowling's public anti-trans stance, to race issues in the film and theater casting of expansions of the Harry Potter series beyond the original six books. The editors Sarah Park Dahlen and Ebony Elizabeth Thomas corral these various perspectives on the "other" in the Harry Potter series into three main sections. The eight essays in part 1, "Race, Gender, and Gender Identity," address how encounters with the other are framed and presented in various texts of the wizarding world, and how fans have reacted. In this section, I found the essay "The Magical (Racial) Contract: Understanding the Wizarding World of Harry Potter through Whiteness" by Christina M. Chica to be a particular standout. Chica posits that in the world of Harry Potter, "wizardness" can be seen as an analog of whiteness. Explaining how "Wizardness (Whiteness) is maintained by property and power over others" (72), Chica details the ways in which the privileges of "wizardness" have political, moral, and legal ramifications in the series. Her essay [End Page 420] has changed the way I think about the functions of magic in the series. Part 2 of Harry Potter and the Other, "#BlackHermione," is much smaller and more focused. The three essays in this section explore the varied fan reactions to the casting of a Black actress to play Hermione in the stage production of Harry Potter and the Cursed Child, and analyze J. K. Rowling's tweet endorsing the casting decision. In this section, Ebony Elizabeth Thomas's chapter "Hermione is Black: Harry Potter and the Crisis of Infinite Dark Fantastic Worlds" describes her own experiences as a Black woman in the Harry Potter fandom of previous decades, and provides a useful framework for how fans and scholars are expected to "reconcile multiple storyworlds" (194). Thomas notes that this chapter is a "truncated version of the original" sixth chapter of her book The Dark Fantastic: Race and the Imagination from Harry Potter to Hunger Games (201). In part 3, "History, Pedagogy, and Liberation," the authors of the four essays that comprise this section look at issues of justice within the book series and also in the way the series is used in our world. The final essay of the collection, "The Failed Wizard Justice System: Race and Access to Justice in Harry Potter" by Charles D. Wilson, is a highlight of the collection and a strong finish. Wilson closely examines the way the legal system is portrayed in the Ministry of Magic in the series in order to make clear its various shortcomings. He points out that "this is more of world-building exercise than a focal point of the series" (288), succinctly voicing an underlying issue of so many of the essays in this collection. Wilson's essay, through its critique of the institutions of the wizarding world, clarifies how inconsistent it is in its policies...

Preparation and Study of Some Physical and Mechanical Properties of Plasticized Chitosan Films

Biodegradable polymer-based packaging materials are a practical replacement for traditional plastic packaging made of fossil fuels. The molecular weight and the kind of plasticizer present in these materials are the two primary variables influencing their usability and performance. This study set out to physically blend chitosan to enhance the physical and mechanical properties of chitosan cast films. A chitosan extract with a molecular weight of 2.702x105 g/mole with an 80% degree of deacetylation level was produced from the shells of local shrimp. Chitosan films plasticized with varied w/w ratios of diethylene glycol and poly(ethylene glycol) with molecular weights of 400 and 1500 g/mole were produced by casting from 2%acetic acid solutions. By using FTIR to analyze them, it was found that their spectra were compared to those of native chitosan, showing that the main backbone of the chitosan structure was unaffected. An examination of the mechanical properties of the films revealed that the results of the tensile strength measurement showed that the combination of diethylene glycol and poly(ethylene glycol) improved the mechanical properties of chitosan as films were obtained with more elasticity than unplasticized chitosan with better solubility.

The Effect of Beeswax and Glycerol Addition on the Performance of Bioplastic Film Made of Konjac Glucomannan

In this study, bioplastics made of Konjac glucomannan have been successfully prepared via film casting method. The effects of addition of beeswax content (i.e. of 0%, 0.5%, and 1%,), as well as glycerol content (i.e. 0.5%, 1%, and 1.5%) on the properties of the bioplastics have been investigated. The bioplastics produced have been characterized for their tensile strength, percent elongation, swelling degree, and biodegradability. The results of this study, showed that most of the bioplastic samples have weight loss of about 95% after the drying process as well as the finished film. The addition of beeswax and glycerol concentrations also increased tensile strength and percent elongation of the bioplastics. The highest value of tensile strength occurred at bioplastic film with a concentration of 1.5% beeswax and 1% glycerol (i.e. Sample C3) with a value of approximately 3.5 MPa. Whereas, the highest percent elongation value occurred at bioplastic film with a concentration of 1.5% beeswax and 1% glycerol (i.e. Sample C3) with a value of approximately 23.29%. These tensile and percent elongation values were higher or comparable to other bioplastic samples made from starch of different raw materials reported by literatures. In the other hand, the addition of beeswax and glycerol decreased the degree of swelling. The degree of swelling for all the bioplastic film samples were in the range of 316.77 – 481%.

Colloidal Crystal Films with Narrow Reflection Bands by Hot-Pressing of Polymer-Grafted Silica Particles.

Previous reports have shown that colloidal crystal (CC) films with visible Bragg reflection characteristics can be fabricated by the surface modification of monodisperse silica particles (SiPs) with poly(methyl methacrylate) (PMMA) chains, followed by hot-pressing at 150 °C. However, the reflection bands of the CC films were very broad due to their relative disordering of SiPs. In this report, we attempted to fabricate the CC films using SiPs surface-modified with poly(n-octyl acrylate) (POA) chains by hot-pressing. When the cast films of POA-grafted SiPs were prepared by hot-pressing at 100 °C, the reflection bands were narrow rather than those of CC films of PMMA-grafted SiPs. This can be ascribed to easy disentanglement of POA chains during the hot-pressing process, thereby enabling the formation of well-ordered CC structures. Moreover, the reflection colors of CC films could be easily tuned by controlling the molecular weight of POA chains grafted on the SiP surface.

Thermal stability and antibacterial activity of Er2O3, and Co3O4 scattered in polycaprolactone

The development of a biocompatible wound dressing with good antibacterial and fasting for healing skin wounds is still a challenge. Through the film casting, a polycaprolactone (PCL) scaffold is manufactured with different ratios of metal oxides such as Erbium oxide (Er2O3) and Cobalt oxide (Co3O4). The fabricated films were examined using XRD, SEM, FTIR, and XPS. The study of surface morphology exhibits diameters of pores in the range of 1–7 µm. The contact angle tested with a drop of water and showed that it is in decreased from 55.67˚ for pure PCL then lowered to 47.85˚ for Er2O3@PCL and slightly decreased to 41.195˚ for Co3O4@PCL and a significant decrease occurred to 34.435˚ for Er2O3/Co3O4@PCL and then it slightly increased to 38.02˚ for Er2O3/Co3O4/GO@PCL. In addition, the TGA started from room temperature up to 200 °C by a weight loss of around 3 %. The cell viability is examined for Er2O3/Co3O4/GO@PCL and it showed that the IC50 at 4000 µg/ml and with lowering the concentration, the viable cells tend to increase. On the other hand, an antibacterial test against E. coli and S. aureus showed high antibacterial activity in Er2O3/Co3O4/GO@PCL. The wound bandages were developed using loaded materials which represent good biocompatibility, biodegradability, and high antibacterial behavior that inhibit bacterial growth on the surface of the wound which might accelerate the wound healing period. Moreover, it has been approved that, the surface porosity might enhance the mutual transfer of gases between the wound and the outer environment.

The influence of calcium carbonate and its modifications on the extrusion process and selected functional properties of polypropylene cast films

The purpose of the article was to determine the influence of calcium carbonate and its modification (with stearic acid) on selected properties of composite polypropylene films and their processing. Polypropylene composites containing, respectively, 5, 10, 20 and 30 wt% filler, were made in twin-screw extrusion process with cold granulation. Films, on the other hand, were produced in single-screw extrusion process (an extruder with a screw with diameter d = 20 mm and ratio l/d = 24) using a flat head (so-called cast films) and a chill roll type cooling and pull-back device. The pull-back rotational speed was selected so as to obtain films of a thickness of approx. 120 µm, irrespectively of the composite being processed. The assessment of the effect of the addition of applied fillers on the magnitude of the melt volume-flow rate (MVR) of polypropylene and the processing characteristic of extrusion process was made (the flow resistance and the variations in volumetric flow rate were determined). It was demonstrated how variations in the processability of polymeric material determined the correction of extrusion process setup parameters (pull-back system speed). The processability of composite films under extensional flow conditions was also determined by evaluating the extensional viscosity (ηE) of the composites. The strength values of composite films were determined under static tension conditions and in puncture tests. The effect of the content and modification of CaCO3 on the film haze and gloss was also assessed. The investigation carried out has demonstrated a direct effect of the addition of calcium carbonate and its modification on the processability and selected functional properties of composite films. The study has also proved that stearic acid is an effective modifier of processing properties, not only in shear flow conditions, but also under extensional flow conditions – smaller ηE values are exhibited by films containing modified calcium carbonate.

Investigation of preparation and properties of Ti3SiC2/Al2O3 multilayered composites

AbstractTi3SiC2/Al2O3 multilayered composites were prepared by the combination of tape casting and hot pressing sintering. The slurry was produced by adjusting the amounts of each organic material, including triethyl phosphate (TEP) as a dispersion, polyvinyl butyrate (PVB) as a binder, dioctyl phthalate (DOP) as a plasticizer, and anhydrous ethanol as an organic solvent. When TEP content was 3 wt.%, PVB content was 4.5 wt.%, R‐value (DOP/PVB) was 1.4, and solid content was 38 wt.%; the cast film with a smooth surface, good flexibility, and uniform thickness was obtained after defoaming, tape casting, and drying. Three samples were prepared, namely, S1–S3. The S1 was monolithic Ti3SiC2/Al2O3 (mass ratio is 1:1) composites. S2 and S3 were Ti3SiC2/Al2O3 multilayered composites, which matrix layers were Ti3SiC2/Al2O3 composites (mass ratio is 1:1) and Al2O3, respectively, and their interface layer was Ti3SiC2. S1–S3 were also sintered at 1550°C. The bending strength of multilayered materials were lower than that of monolithic material, but the fracture toughness of multilayered materials significantly increased. Due to the introduction of Ti3SiC2 interface layer, the friction coefficient and wear rate of Ti3SiC2/Al2O3 multilayered composites were reduced by 30.7% and 33.8%, respectively, compared with monolithic material.

Highlighting the Compositional Changes of the Sm2O3/MgO-Containing Cellulose Acetate Films for Wound Dressings.

The development of wound dressing materials with appropriate specifications is still a challenge to overcome the current limitations of conventional medical bandages. In this regard, simple and fast methods are highly recommended, such as film casting. In addition, deliverable nanoparticles that can act to accelerate wound integration, such as samarium oxide (Sm2O3) and magnesium oxide (MgO), might represent a potential design with a novel compositional combination. In the present research, the casted film of cellulose acetate (CA) was mixed with different ratios of metal oxides, such as samarium oxide (Sm2O3) and magnesium oxide (MgO). The tests used for the film examination were X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The SEM graphs of CA films represent the surface morphology of Sm2O3@CA, MgO@CA, and Sm2O3/MgO/GO@CA. It was found that the scaffolds' surface contained a high porosity ratio with diameters of 1.5-5 µm. On the other hand, the measurement of contact angle exhibits a variable trend starting from 27° to 29° for pristine CA and Sm2O3/MgO/GO@CA. The cell viability test exhibits a noticeable increase in cell growth with a decrease in the concentration. In addition, the IC50 was determined at 6 mg/mL, while the concentration of scaffolds of 20 mg/mL caused cellular growth to be around 106%.

Preparation of polyurethane coating formulation based on dihydropyridine derivatives as an insecticide and antifungal additives for surface coating applications

Pyridine derivatives are prepared and evaluated before being incorporated into polyurethane coating formulations to create antifungal and insecticidal coating compositions. Different analyses, including Fourier transform infrared (FTIR), mass, proton nuclear magnetic resonance (1HNMR), and carbon-13 nuclear magnetic resonance (13C NMR) spectra, were used to confirm the synthesized compounds. The material has been coated using a polyurethane coating mixture. Gloss, scratch resistance, flexibility, and adhesion are some of the coating attributes investigated; mechanical capabilities include impact resistance and shore hardness, and physicochemical properties such as chemical resistance of coated polyurethane (PU) samples are also investigated. PU coatings were applied to substrates to measure coating properties. The mechanical properties of the PU cast films were measured. The results of the experiments revealed that all PU coatings based on dihydropyridine derivatives had good scratch resistance which varied from > 1.5 to > 2 kg. While reducing gloss value varied from 65 to 85, there is no effect of the prepared compounds in the other mechanical test. These PU coatings have excellent chemical resistance except the alkali resistance as evidenced by their physicochemical properties. The observed antifungal and insecticide activities indicated that dry wood coated with PU based on dihydropyridine derivatives is promising for resistance to these insects and fungi, in comparison with the paint as blank. The results revealed that the inhibition zones diameter by compound 2 were 25.1 ± 0.69, 23.2 ± 0.94, 20.16 ± 0.62, 20 ± 0.80, and 18 ± 0.81 mm against A. terreus, A. niger, A. flavus, C. albicans, and A. fumigatus, respectively, whereas the inhibition zones (IZ) diameter by compound 3 were 22.56 ± 0.30, 21.03 ± 0.49, 21.03 ± 0.61, 21 ± 0.66, and 20 ± 0.78 mm versus A. niger, A. fumigatus A. flavus, C. albicans, and A. terreus, respectively. The ordering activity against insects increased as the dose concentration of the pyridine derivatives was increased.

Selecting the most appropriate formulation excipient for manufacture of amorphous solid dispersions: a case study of lumefantrine

This work demonstrated the importance of pre-formulation studies and proposed a generalised scheme for excipient screening in the early stage of amorphous solid dispersion(ASD) system development by profiling the excipients’ capability to solubilise, amorphisise, and stabilise the chosen active pharmaceutical ingredient (API) in an effort to rank their suitability. Lumefantrine, an antimalarial active compound with both poor solubility and permeability, was used as a model API and solvent evaporation film casting was used to prepare the candidate ASD matrices in this work. 

3D-Printed Pectin/Carboxymethyl Cellulose/ZnO Bio-Inks: Comparative Analysis with the Solution Casting Method.

Bio-inks consisting of pectin (Pec), carboxymethyl cellulose (CMC), and ZnO nanoparticles (ZnO) were used to prepare films by solution casting and 3D-printing methods. Field emission scanning electron microscopy (FE-SEM) was conducted to observe that the surface of samples made by 3D bioprinter was denser and more compact than the solution cast samples. In addition, Pec/CMC/ZnO made by 3D-bioprinter (Pec/CMC/ZnO-3D) revealed enhanced water vapor barrier, hydrophobicity, and mechanical properties. Pec/CMC/ZnO-3D also showed strong antimicrobial activity within 12 h against S. aureus and E. coli O157: H7 bacterial strains compared to the solution cast films. Further, the nanocomposite bio-inks used for 3D printing did not show cytotoxicity towards normal human dermal fibroblast (NDFB) cells but enhanced the fibroblast proliferation with increasing exposure concentration of the sample. The study provided two important inferences. Firstly, the 3D bioprinting method can be an alternative, better, and more practical method for fabricating biopolymer film instead of solution casting, which is the main finding of this work defining its novelty. Secondly, the Pec/CMC/ZnO can potentially be used as 3D bio-inks to fabricate functional films or scaffolds and biomedical applications.

Morphology, structure and property of high consistency mechano-enzymatic fibrillated cellulose: Effect of treatment consistency of bamboo pulp fibers

High consistency mechano-enzymatic fibrillation of cellulose fibers is a desirable approach to producing high solid fibrillated cellulose (HSFC) materials in a green fashion, which can reduce water consumption and lower logistic costs as well as carbon footprint. Here, we mainly investigated the effects of various treatment consistencies (15–45%) of bamboo pulp fibers during the mechano-enzymatic processing on the morphology, structure, and property of the resulting HSFC materials. The results revealed that the 35% treatment consistency was the most favorable for producing fibrillated cellulose materials comprising the most nanoscale fibrils, despite a small fraction of unfibrillated microfibril bundles existing. The fibrillated cellulose obtained at the 35% consistency had the highest water retention value, yielding a cast film with the highest mechanical performance. The 15% treatment consistency generated HSFC materials with the least degree of fibrillation, in which most were shortened yet micro-sized fiber fragments. Regardless of treatment consistencies, the HSFC materials almost retained cellulose crystallinity and thermal stability. The results suggest that mechano-enzymatic fibrillation at a suitable treatment consistency is crucial to producing the most highly fibrillated cellulose.