Nonwoven Film Research Articles

Electrospinning of pullulan-based orodispersible films containing sildenafil

Feasibility of electrospinning in the manufacturing of sildenafil-containing orodispersible films (ODFs) intended to enhance oxygenation and to reduce pulmonary arterial pressure in pediatric patients was evaluated. Given the targeted subjects, the simplest and safest formulation was chosen, using water as the only solvent and pullulan, a natural polymer, as the sole fiber-forming agent. A systematic characterization in terms of shear and extensional viscosity as well as surface tension of solutions containing different amounts of pullulan and sildenafil was carried out. Accordingly, electrospinning parameters enabling the continuous production, at the highest possible rate, of defect-free fibers with uniform diameter in the nanometer range were assessed. Morphology, microstructure, drug content and relevant solid state as well as ability of the resulting non-woven films to interact with aqueous fluids were evaluated. To better define the role of the fibrous nanostructure on the performance of ODFs, analogous films were produced by spin- and blade-coating and tested. Interestingly, the disintegration process of electrospun products turned out to be the fastest (i.e. occurring within few s) and compliant with Ph. Eur. and USP limits, making relevant ODFs particularly promising for increasing sildenafil bioavailability, thus lowering its dosages.

Preparation and characterization of bioactive polyvinylpyrrolidone film via electrospinning technique.

Electrospinning technique became a very common and effective method to fabricate nonwoven films with a large surface area for different purposes especially in the biomedical field. Antimicrobial submicron fibrous films based on polyvinylpyrrolidone (PVP) doped with silver nanoparticles (Ag-NPs), Zinc Oxide (ZnO), and (Ag-NPS/ZnO), were successfully fabricated via the electrospinning technique. The morphology and the elemental configurations of the as-prepared films were studied by using scanning electron microscope with EDX. While the phase formation and crystal structures were determined by using XRD analysis. The antibacterial effect was investigated against one of the most common Gram-negative bacteria Klebsiella pneumoniae by using a modified Kirby-Bauer disc diffusion method. The results showed that the doping nanoparticles were uniformly loaded on the surface of the fabricated film fibers. By using Scherrer equation the calculated average crystallite sizes of Ag-NPs, ZnO, and Ag-NPs/ZnO on PVP fibers were 63, 30, and 44 nm, respectively. The antimicrobial activity against Klebsiella pneumoniae showed the growth inhibition zones in the bacteria plates of 23.3, 54, and 60.6 mm for the samples of Ag-NPs/PVP, ZnO/PVP, and Ag-NPs/ZnO/PVP, respectively. The antimicrobial efficiency increased by forming nanocomposites of both ZnO nanoparticles and Ag nanoparticles inside the film. RESEARCH HIGHLIGHTS: Novel antimicrobial submicron electrospun membranes based on polyvinylpyrrolidone doped with silver, zinc oxide nanoparticles were successfully fabricated. The fabricated samples showed bactericidal activity against K. pneumoniae.

Withdrawal Notice: Beauty and Wellness Turn Towards a Green Economy

: Beauty and wellness remain for both women and men an important target also because global attractiveness is considered a cue indicating the ability to maintain beauty and wellness. Consequently neuromarketing has occurred as an innovative mean to interact with consumer's trend, actually looking for high-quality and natural cosmetics and food. By the biometric studies, in fact, it seems possible to verify the consumers’ willingness to buy the right products they are looking for. On the other hand, customers are requesting cosmeceuticals and nutraceuticals acting positively on the superficial appearance of face and body, seem to be able to boost the immune system also, limiting the stress conditions. This general disease is induced by the actual way of living on a planet invaded by a great quantity of waste released from human’s activities. The consequent pollution alters the ecological balance of the body, influencing negatively the life of animals and plants also. Thus, the induced stress, further increased by the COVID-19 spread, could change the human brain' neural conditions. Consequently, in humans the production of both neurons' stem cells and cortisol could decrease, while in plants, the patterns of growth could affect the leaf cuticle and stomatal conductance. Thus brain, under psychosocial stress, actively demands energy from the body, eliciting a marked increase in eating by a major carbohydrate intake which sacrifices the requirements of other organs. In any way, pollution has wide-ranging adverse health and social effects, further worsened by an increased worldwide aged population who, requiring more food and goods, increases the waste production. What the proposed solution? To change the way of consuming and producing, it is necessary to optimize the material resource, minimizing waste that should be recycled and reused by a green economy approach. So doing, it could be possible to realize a new industrial Renaissance reducing consumption of water, energy and natural raw materials. Thus the necessity to use sustainable technologies and materials for maintaining human wellbeing in an environment in which the species' biodiversity could be assured. At this purpose, chitin nanofibrils(CN), nano-lignin (NL) and their derived compounds have been proposed to make nanoparticles (NPs) by the use of water as solvent. These NPs, loaded with different active ingredients, may be embedded into innovative natural or man-made polymers and used to make biodegradable carriers in the form of non-woven tissues and films. Depending on the polymers and on the actives loaded into the fibers, these new vehicles may be used to produce smart cosmeceuticals, nutraceuticals or advanced medications. It is interesting to underline that all these innovative NPs and tissue/films can be produced by natural polymers and ingredients, obtained from waste materials and produced by sustainable technologies at low consumption of water and energy, according to the new green economy.

Биодеградация ультраволокнистых материалов на основе смесей полигидроксибутирата и полилактида

Comparative studies of ozone and oxygen effects, hydrolytic destruction, biodegradation of nonwoven fibrous and film materials based on mixtures of natural polymers - polyhydroxybutyrate and polylactide are carried out in this work. Fibers were obtained from a solution in chloroform via electrospinning method. The films were formed by pouring a solution onto a glass substrate. The structure of materials was investigated by methods of electron and optical microscopy, DSC, EPR spectroscopy. It has been shown that materials enriched with polylactide have greater resistance to oxidation, low resistance to hydrolysis and UV irradiation, in comparison with polyhydroxybutyrate.

Fabrication on the Flexible Supercapacitor Based on the Polypyrrole Deposited on Polyethylene/Polypropylene Non-Woven Film

Non-woven films of polypropylene/polyethylene (PP/PE) are usually used as filter membrane or diaphragm because of their excellent mechanical strength and chemical stability. Here, by using PP/PE as substrates, the composite films of FeTS/(PP/PE) are prepared via drop-coating iron p-toluenesulfonate (FeTS) on the PP/PE. Polypyrrole (PPy) is then deposited on PP/PE non-woven films to form the PPy/(PP/PE) composites by reacting the pyrrole vapor with oxidant of FeTS. The structure of PPy/(PP/PE) prepared under different conditions have been characterized in detail. Using H3PO4/polyvinyl alcohol (PVA) as the gel electrolyte, the flexible symmetric electrochemical capacitors (FEC) of PPy/(PP/PE)//PPy (PP/PE) are prepared and the properties of the devices are determined. The results show that the optimized FEC exhibits relatively high areal specific capacitance (246.6 mF cm–2 at 2 mV s–1 scan rate), excellent cyclic stability (capacitance retention is 92.5% after 20 000 cycles), and excellent flexibility (the capacitance retention is 90.0% after 2000 and 81.3% after 3000 repeated bending cycles), which indicate that this kind of FEC may have potential application in flexible electronic device.

Performance of frost protection structures on yield and post-harvest quality of organically grown winter dawn strawberry

Low tunnel protected cultivation of organically grown strawberry (winter dawn) was carried out to standardize the cladding material and the height of structure for enhancing the yield and post-harvest quality in Punjab North India. Three different design of low tunnels i.e. three different heights; 45 cm, 60 cm and 75 cm and three claddings; thin plastic film (50 microns), UV stabilised plastic sheet (200 microns) and non-woven film (20 GSM) were used in the trials. Microclimate parameters, soil moisture and soil temperature inside the installed structures were analyzed throughout the experiments. The maximum yield of crop, number of fruits (45), maximum weight (28g) was observed in the tunnel of size 45 cm with non-woven 20 GSM followed by UV 200 micron of 60 cm height and minimum values were observed in other structures and open. All the tunnels maintained favourable soil and canopy temperature for the growth of crop and it was observed that crop grown inside tunnels were protected from any kind of frost injury and exhibited better post-harvest quality than the strawberry grown in open.

Effects of applying ramie fiber nonwoven films on root-zone soil nutrient and bacterial community of rice seedlings for mechanical transplanting

Raising rice seedlings in flat trays has become the main method for mechanized transplanting of rice in China. However, seedling blocks raised by this method were easily cracked in practice, and this problem can be solved by padding a thin ramie fiber nonwoven film on the bottom surface of seedling tray. This study was conducted to determine the effects of this film on root-zone environment of rice seedlings. The results showed that on the 10th day after sowing, the soil inorganic nitrogen, especially nitrate nitrogen, content in the root-zone of the film treatment were considerably higher than in the no-film treatment, in contrast, the soil organic matter content was lower in the film treatment, and by the 20th day, the gap between treatments was enlarged. After applying the film, the Chao 1 index and Shannon index values for the soil bacterial community diversity decreased, and the rice seedlings were shorter, had higher root/shoot ratios, lower nitrate contents, and higher soluble sugar contents. We conclude that application of the ramie fiber nonwoven film resulted in substantial changes in the soil nutrient and bacterial community in root-zone in a short time, which significantly impacted the growth and development of rice seedlings.

Film Fiber Radio-Absorbing Material

The dielectric properties of nonwoven webs and polymer films filled with dispersed carbon web, as well as multilayer materials obtained by addition of webs and films, were investigated. Webs and films have a pronounced interference mechanism of absorption of electromagnetic waves. Dielectric properties with an asymmetric structure relative to the middle of the thickness of the multilayer materials depend on the side on which electromagnetic radiation enters the material. Multilayer materials based on nonwoven web and polymer films have an interference absorption mechanism, but their use expands the frequency range of absorption of electromagnetic radiation.

Development and Characterization of Self -assembled Bacterial Cellulose Nonwoven Film

ABSTRACT Bacterial cellulose is one of the widely discussed biomaterials due to its unique physical, mechanical and chemical characteristics. In this research, bacterial cellulosic film (BCF) was developed using Acetobacter xylinum strain in green tea as a source of carbon under static culture conditions. The developed BCF was evaluated for their morphological properties using a scanning electron microscope and the approximate fiber diameter noted as 38–40 nm. The purity of the cellulose evaluated through an X-ray diffraction method identified that the developed cellulose is Iα rich – triclinic type with 89.61% of crystallinity. The thermal behavior of the BCF was evaluated using TGA and DSC. The results indicated that the major weight loss occurred from 250 to 500°C. The glass transition temperature (Tg) of the developed BCF was very high and it was 165°C. Concerning the mechanical properties, the BCF had lower tensile strength (13.82 Kgf/Cm2), Elongation (10.13 mm) and air (19.72 cm3/cm2/sec) and water vapor permeability value (151 g/m2/day) than the woven cotton fabric. However, the water absorbency (0.7 s) and water holding capacity (320%) are superior to the cotton fabric. The contact angle of the BCF was noted around 28.53°, which is an indication of the higher hydrophilic nature of the BCF. These results provide an insight into the potential applications of bacterial cellulosic material in the apparel and textile sector.

Enhancing the spreading dynamics of oil drops over nanofiber substrates

The spreading dynamics of small oil drops over nanofiber layers has been investigated to improve the oil spill management process. Although liquid transport studies have been used to compare different substrates, the actual effect of the fibrous substrate structure has not been precisely investigated. Nanofiber substrate structures consist of micro- and nanocapillaries that vary in diameter and length and are interconnected in a complex manner. Migration of a liquid from one layer to another as well as on the same layer is an important part of the sorption process in nanofiber substrate structures. In this work, the problem under investigation provides spreading small oil drops over a thin porous layer nanofiber until saturation. An experimental evolution describing the drop spreading has been deduced, which shows the speed of spread of the oil drop is significantly affected by the substrate areal weight. The oil drop area over a dry porous layer seems to be caused by the interchange of two spreading velocities, one over the layers and the other penetration of the oil drop through the pores of the substrate. The higher the oil spreading speed, the lower the permeation of the oil into the porous nanofiber substrate and vice versa. To increase the absorption of the nanofiber substrate, adding a nonwoven thin film to cover the nanofiber layers was studied. It was revealed that the presence of such film significantly accelerates the oil-drop spreading speed by up to 300% and reduces the overall time of the oil drop's life.

Interfacial failure boosts mechanical energy dissipation in carbon nanotube films under ballistic impact

High-performance fabrics with outstanding mechanical performance hold great promises in load-bearing and protection applications, where the capability to dissipate mechanical energy is one of the key figures of merits. We study in this work the microstructural evolution and mechanical responses of carbon nanotube films upon ballistic impact. Both cross-ply laminated and non-woven films are explored by molecular dynamics simulations, which are validated by penetration experiments. The results indicate that high stiffness and strength of carbon nanotubes offer excellent mechanical resistance. In addition to brittle fracture of the nanotubes, ductile failure of van der Waals interfaces between the nanotubes in forms of detachment or sliding opens new channels to dissipate mechanical energy resulted from the impact. The reversible nature of intertube interaction endows the film self-healable capabilities, which is superior compared to polymers that are widely used in industry, and graphene multilayers that are fractured by emitting radial cracks. Combined with the fact that carbon nanotubes feature outstanding thermal and chemical stabilities, these findings bring perceptive insights into the design of strong yet dissipative materials for load-bearing and protection applications in harsh environment.

A Biodegradable Ramie Fiber-Based Nonwoven Film Used for Increasing Oxygen Supply to Cultivated Soil

Plastic agricultural nonwoven films are traditionally used as covering materials, and are prone to cause various ecological problems due to their poor biodegradability. In this paper, a ramie fiber/starch nonwoven film was prepared, and was used as bedding material, that was covered by cultivated soil as opposed to covering it. The biodegradability and porosity characteristics of the film were analyzed, and its effect on oxygen supply to soil was investigated. Results showed that the prepared film had good biodegradability (65.6% after 72 days), and had a loose and porous structure, with the main pore size being in the range of 250–300 μm. After the soil moisture content was reduced to about 44%, the oxygen concentration in the soil that was in close contact with the film, which padded the bottom surface of the plate, rose sharply and then kept stable at 20.1%, whereas soil directly in contact with the plate remained extremely anoxic (0.2%). It was concluded that use of the prepared film increased the oxygen supply to the soil in contact with it, which sufficiently compensated for the oxygen consumption caused by soil microbial activities. Thus, the prepared film is very suitable in short-term plant cultivation within containers where anoxia often occurs.

Investigating alternative methods for enhancing the establishment of the zoophytophagous mirid Nesidiocoris tenuis (Reuter) in greenhouse tomato crops

The zoophytophagous mirid Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is an effective natural enemy of some major pests of tomatoes in the Mediterranean region. In this area the colonization of protected tomato crops by this biocontrol agent may be hampered by the application of measures aimed at avoiding the transmission to tomato plants of insect-vectored diseases (e.g. TYLCD). Furthermore, various factors, such as the scarce availability of preys on crop plants and the severe deleafing of tomato plants, may affect the population build-up of artificially introduced predatory mirids. Since these natural antagonists have become commercially available in Europe, several methods have been explored to enhance their establishment on greenhouse tomatoes. This work reports the results of experiments carried out to investigate the effects of different release methods on the establishment of N. tenuis in commercial greenhouse tomato crops grown in southern Sardinia (Italy). The techniques tested can be summarized as follows: a) release of mirids before transplanting; b) introduction into release points covered by non-woven films; c) introduction into uncovered feeding points; d) traditional release method. N. tenuis was introduced at a rate of 0.8 individuals per stem grown (2.4-3.2 mirids plant-1) in crops planted during late summer. All methods except the traditional one envisaged the distribution of 0.01 g plant-1 of Ephestia kuehniella Zeller eggs, supplied three times at two-week intervals, as an alternative food source. Two months after planting, pre-plant release and the introduction into covered or uncovered release points allowed the predatory mirid to reach significantly higher densities in comparison with the traditional release method. Under the conditions tested, the anticipation of release and the supply of an artificial food source appear to be decisive factors for enhancing the establishment of N. tenuis in greenhouse tomato crops.

Chitosan‐finished Antheraea mylitta silk fibroin nonwoven composite films for wound dressing

ABSTRACTIn this study, we aimed to produce nonwoven wound‐dressing films made of Antheraea mylitta (tasar) silk fibroin by a solution‐casting method. These nonwoven films were finished with chitosan solutions of different concentrations ranging from 0.75 to 2% w/v with a pad–dry method to fabricate nonwoven composite films. Chitosan‐finished tasar fibroin nonwoven composite films (CMTFFs) showed higher mechanical and dynamic mechanical properties as compared to nonwoven tasar fibroin. The physical, structural, and thermal properties of the films were investigated. The hemocompatibility, cytocompatibility, and biodegradation tests showed that the CMTFF was a promising material for use as a wound dressing. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44341.

Enhancement of Toxic Gas Detecting Ability of Film Type Colorimetric Sensor

In this study, we tried to develop the in situ coating methods of hydrophilic polymer solution containing water soluble dye on nonwoven sheet for the colorimetric film sensor. And color change of coated dye according to contact various gas samples (as strong acid and base, chloroform, ammonia and HF) of this dye-coated nonwoven film was examined for the application of chemically toxic materials detecting tools in the actual site of working place without aid of any kinds of detecting devices. By the addition of electron transfer agent (quinone derivatives), quick color change behaviors were observed within 10 seconds under the contact of various toxic gases in general condition(room temperature, 50% humidity).

DEVELOPING IMPROVED METHODS FOR THE RELEASE OF MACROLOPHUS PYGMAEUS (RAMBUR) (HETEROPTERA: MIRIDAE) IN SARDINIAN TOMATO GREENHOUSES

The release of biocontrol agents for the management of arthropod pests on greenhouse tomatoes is an increasingly widespread technique in Europe. The predatory mirid Macrolophus pygmaeus was initially used for control of the greenhouse whitefly, Trialeurodes vaporariorum, but its range of application expanded when it was found to have the potential for management of the tomato leafminer, Tuta absoluta. One of the constraints that still limits the use of this beneficial in Sardinian greenhouse crops is its slow population growth, frequently responsible for unsatisfactory control of target pests. To evaluate the effects of two innovative release methods on the establishment and population build-up of M. pygmaeus in tomato crops, experiments were carried out under semi-field and field conditions. The two techniques tested for the introduction of the mirid were pre-plant release and release in confined areas. Pre-plant releases were done in the nursery, while confined area releases were done in the production greenhouse where the mirid was introduced on plants covered with a non-woven film for six weeks and provided with a food source (Ephestia kuehniella eggs). In both cases, approximately 0.8 adult mirids per plant were released. The experiments were conducted in glasshouses where spring tomato crops were grown for up to four months. The method that achieved the most promising results in terms of mirid population build-up (up to 9.6 individuals per plant) was the introduction in confined areas. However, when the insects used were purchased through ordinary retail channels, insufficient population growth and inadequate control of target pests were observed. The pre-plant release method failed to significantly enhance the build-up of M. pygmaeus population, and the peak density observed by eight weeks after its introduction was 1.1 individuals per plant for predators introduced in both a heated and unheated nursery.

Core@dual‐Shell Nanoporous SiO2–TiO2 Composite Fibers with High Flexibility and Its Photocatalytic Activity

Structural design is of great importance to the performance of photocatalysts in environmental remediation. Therefore, micro/nanofibrous morphology and nanoporous local structures have been found to be beneficial to improve the photocatalytic activity. In this investigation, we report the design and fabrication of flexible and thermal stable nanoporous SiO2–TiO2 composite fibers as efficient photocatalysts. Combining electrospinning and modified Stöber techniques, core‐shell and mesoporous SiO2 fibers with high flexibility were fabricated and employed as the scaffold for supporting TiO2 nanoparticles. A nanoporous shell of TiO2 nanoparticles was then muffled over the SiO2 fibers to form core@dual‐shell SiO2–TiO2 composite fibers with hierarchically porous structure, which were conveniently patterned into a nonwoven, recyclable film. This nonwoven film exhibits better photocatalytic activity for Rhodamine B degradation under UV irradiation compared with some other TiO2‐based materials reported in recent years.

Flexible and thermally stable SiO2–TiO2 composite micro fibers with hierarchical nano-heterostructure

TiO2-based micro/nano fibres with secondary hierarchical structure have been extensively studied concerning a wide range of applications. However, simultaneous optimization of the flexibility and thermal stability of these materials still remains a big challenge. In this investigation, the successful fabrication and characterization of TiO2–SiO2 composite micron fibers with both high flexibility and excellent thermal stability are reported. Electrospun flexible SiO2 fibers were used as the scaffold for supporting TiO2 nanostructures. Three distinguished layers of porous SiO2, anatase TiO2 nanoparticle and rutile TiO2 nanorods were muffled over the SiO2 fibers stepwise, forming a unique core@multi-shell architecture with hierarchical structure. Such elaborately designed core@multi-shell TiO2–SiO2 fibers present high flexibility, excellent thermal stability, large specific surface area and high porosity. Moreover, they are easy to be patterned into nonwoven film with hierarchically porous structure, which is promising for many applications. We evaluate the water purification performance of the TiO2–SiO2 nonwoven film with Rhodamine B as a model organic pollutant. Efficient removal of Rhodamine B from water was implemented via simple filtration under UV irradiation, and regeneration of the photocatalytic functionality of the film from organic contamination was conveniently realized merely through calcination.

Preparation and Analysis of Cotton Nonwoven Film Strengthened by Chitosan

The invention of plastic film has brought not only convenience but also environmental pollution to people. To use natural vegetable fiber is the mainly approach to solve the problem. In this paper, the waste cotton fiber was used as raw material and the cotton nonwoven sample was made through wet laying process, after strengthened by chitosan, degradable film was prepared. The performances of the film were characterized and analyzed by testing the strength, air permeability, moisture permeability and other indexes. The results showed that chitosan can be used as strengthening agent, the performances of the film strengthened were improved, and it was degradable.

Silver nanoparticles decorated, flexible SiO 2 nanofibers with long-term antibacterial effect as reusable wound cover

As wound cover, electrospinning-derived organic polymer nanofibers usually cannot bear calcinations to remove contaminants from wound for regeneration of their functionality, thus are not reusable. In this investigation, we make an exploration of inorganic SiO 2 nanofibers as reusable wound cover. SiO 2 nanofibers here are fabricated with the sol–gel technique and the electrospinning method. Silver nanoparticles (Ag NPs) are grafted on fiber surface through post treatment to endow this material with antibacterial effect. Our results demonstrate the SiO 2 nanofibers are very soft and flexible. They can be conveniently patterned into nonwoven film (the required shape of wound cover). The Ag NPs grafted SiO 2 nanofibers can efficiently inhibit the proliferation of Escherichia coli with a long-term antibacterial effect. More importantly, this inorganic antibacterial wound cover can be renewed through calcinations without lost of its flexibility and antibacterial effect. Consequently, the Ag NPs grafted SiO 2 nanofibers in this investigation are very suitable to be applied as reusable wound cover.