Puncture Strength Research Articles

Diagnostic Accuracy of Toluidine Blue Electrospun in Detecting Oral Potentially Malignant Disorders.

Oral potentially malignant disorders (OPMDs) with epithelial dysplasia can progress to oral squamous cell carcinoma (OSCC). Toluidine blue (TB) has been used in oral screening with various methods. This study aimed to evaluate the sensitivity and specificity of TB-containing electrospun fibers in detecting OPMDs with epithelial dysplasia compared to histopathology. The concentrations of polyvinylpyrrolidone (PVP) and TB were optimized for fiber diameter and puncture strength using the design of experiments method with a central composite design. These optimized fibers were tested on 36 suspected OPMD lesions in 30 patients, followed by a biopsy for histopathological examination. The quadratic and two-factor interaction models described the relationship between TB and PVP concentrations and fiber characteristics. The TB-containing electrospun fibers had 77.3% sensitivity and 35.7% specificity in detecting OPMDs with epithelial dysplasia. The TB-containing electrospun fibers offer advantages such as easy application, cost-effectiveness, and enhanced sensitivity in identifying OPMDs with epithelial dysplasia. However, their diagnostic accuracy is insufficient as a standalone diagnostic method, and they should be considered an adjunctive tool for detecting dysplastic changes in the oral epithelium. Thailand Clinical Trials Registry: TCTR20240429002.

New training simulator for lumbar puncture base on magnetorheological

In response to the difficulties in accurately reproducing the resistance drop generated by puncturing key tissue layers with a needle and the poor experience in existing simulators, based on the continuous controllability and rapid response of magnetorheological fluid under the influence of a magnetic field, this paper proposes a lumbar puncture training simulator(LPTS) that can accurately simulate the puncture feedback force within tissues such as the skin, subcutaneous fat, and supraspinous ligament throughout the entire process. By using a dual rod structure and reasonably arranging the damping channel gap, the influence of mechanical friction and zero-field damping force on the feedback force during tissue progression is minimized. This paper introduces the acquisition and modeling analysis of raw data, and based on this, the design, simulation, and mechanical testing of the simulator are carried out. Finally, a performance testing platform for the simulator is established to evaluate its tracking performance of the expected puncture strength and the reproducibility of the puncture sensation. The results show that the experimental puncture strength deviates from the expected puncture strength by 0.35 N to 0.61 N in the crucial steps of breaking through the supraspinous ligament, interspinous ligament, ligamentum flavum, and dura mater, with a relative error below 10 %.

Thermal comfort and mechanical analysis of vigorous diamond and diaper weaves; warp, weft and balanced float fabrics with equal thread densities

Diamond (pointed twill) and diaper (herringbone twill) woven assemblies are considered ideal for applications where thermal insulation, heat retention, wrinkle resistance, strength, softness, and breathability attributes are crucial. Limited research has been found on the optimization of thermal comfort and mechanical performance of warp face, weft face and balanced float diaper and diamond woven assemblies. In this work six different woven assemblies have been engineered using cotton (cellulosic yarn) on a dobby machine, having warp face (4/2) weft face (2/4) and balanced float (3/3) based diamond and diaper weave designs with equal number of thread densities. Thermal comfort (dry fluid transmission, thermal resistance, stiffness, and overall wet fluid management capability) and mechanical (tensile, puncture and tear strength) tests were performed for developed woven fabrics. The results of diamond warp face sample showed the highest dry fluid transmission and volume porosity. Diamond weft face specimens showed the highest thermal conductivity behavior and diaper weft face exhibited the highest overall wet fluid management capability behavior. Stiffness was the highest in diamond balanced float. Diamond warp faced fabric showed the highest tearing durability and diaper weft face showed the highest tensile resilience in mechanical performance attributes.

Characteristics of soy films as affected by transglutaminase cross-linking and inclusions of pectin and protein enhancers.

Previously, we showed that water extract (soymilk, except pH was increased to 8 from 6.5) of whole soybean could be used directly as a raw material for producing edible soy films by deposition of the film-forming solution (soy extract with enhancers). However, the strength of such soy films needed improvement because they were weak. The purpose of this study was to investigate how transglutaminase (TG) cross-linking reactions and film enhancers, including pectin (low- and high-methoxyl pectin), whey protein isolate (WPI), and soy protein isolate (SPI), improve the physical properties of soy films. Soy films prepared with TG had tensile strength (TS) of 3.01MPa and puncture strength (PS) of 0.78MPa, which were higher by as much as 51% and 30% than that of soy films without TG treatment, respectively. Pectin showed significant effects on the mechanical properties of TG-added soy films in terms of TS, PS, and % elongation. On the other hand, only TS and PS were increased by the addition of WPI or SPI. Heat curing had a significant effect on soy film's physical properties. TG treatment significantly reduced film solubility when soaked in water and various levels of acid (vinegar) and base (baking soda) solutions. Under the experimental conditions of 35 unit TG and 28min of reaction, the degrees of cross-linking were evidenced by the disappearance of individual protein subunits, except the basic subunit of glycinin, and the reduction of 21% of lysine residues of the proteins. HIGHLIGHTS: Edible soy films were made with transglutaminase and about 21% lysine cross-linked. The mechanical strength of soy films was increased by incorporating film enhancers. Transglutaminase enhanced the mechanical properties of soy films.

Effects of washing with boric acid solutions on residual boric acid content, microbiological load, and quality of fresh-cut spinach

Insufficient disinfection of fresh-cut spinach poses significant health risks, along with potential issues like odor, color changes, and softening during short-term storage. To address these challenges, boric acid solutions were explored as an alternative to chlorine washes, which are known to produce toxic compounds. Among various concentrations, 1 % boric acid exhibited the most effective microbial inactivation, leading to substantial reductions in total mesophilic aerobic bacteria, total yeast and mold, and Enterobacteriaceae counts, with reductions of 1.64, 1.38, and 1.77 logs, respectively. Additionally, washing spinach leaves with this solution for 1 min maintained quality parameters, with enhanced antioxidant activity (55.26 mg kg−1 Trolox equivalent), increased total phenolic content (1214.06 mg kg−1 gallic acid equivalent), retention of chlorophyll a (839.16 mg kg−1), chlorophyll b (539.61 mg kg−1) and ascorbic acid content (264.72 mg kg−1). Mechanical properties such as puncture strength (1.81 N) and puncture distance (52.78 mm) also showed favorable outcomes, alongside optimal moisture content at 89.81 %. Notably, residual boric acid content was lowest in spinach leaves (1252.49 mg kg−1) and highest in the wash water (53.88 mg kg−1) after treatment. Scanning electron microscopy images demonstrated maintained tissue integrity, while Hunter Lab readings indicated minimal color changes post-washing. Additionally, sensory evaluations and various physicochemical analyses further supported the efficacy of boric acid washing. Consequently, washing spinach leaves with a 1 % boric acid solution for 1 min yielded favorable results across multiple quality parameters. These findings suggest the potential of boric acid as a safe and effective alternative disinfectant in the fresh-cut produce industry, highlighting its practical implications for food safety and quality. Future research should focus on exploring long-term effects and optimizing washing protocols for broader applications.

Composite Materials as the Basis of Concrete Canvas

Statement of the problem. Composite materials based on mineral components and organic and mineral systems are gradually expanding their presence in the domestic market of materials and building techno-logies. Concrete fabric, as one of the varieties of textile-concrete, can be considered as a composite material whose properties depend both on those of polymeric materials that form its enclosing surfaces and those of the core material, and on the nature of the interaction between the facing and core materials. The purpose of the research presented in the article is to evaluate the main strength characteristics of the concrete canvas, as well as to study the effect of the content of Portland cement, plasticizer and modifying additive on the properties of fine-grained concrete as the basis of the concrete canvas, as well as to evaluate the possible areas of application of the concrete canvas with the obtained properties. Results. In the process of processing the results of the experiment and analytical optimization of the response functions, the fundamentals of the methodology for selecting the composition of modified fine-grained concrete as the basis of the concrete canvas were developed. As a result of the tests, the following characteristics of the material were established: average density ––1450––1500 kg/m3; compressive strength –– not less than 36––38 MPa, puncture strength –– not less than 3 kN; ultimate strength in ben-ding 16––20 MPa. Conclusions. Despite the fact that the thickness of the concrete canvas in the hardened state does not exceed 10 mm, its properties are not inferior to those of other types of textile concrete, i.e., they have high strength characteristics with a relatively small thickness. The most promising areas of application of the concrete canvas are the repair and waterproofing of reinforced concrete structures of hydraulic structures, and the strengthening of slopes.

Variation and interrelationships in the growth, yield, and lodging of oat under different planting densities.

Oat is a dual-purpose cereal used for grain and forage. The demand of oat has been increasing as the understanding of the nutritional, ecological, and economic values of oat increased. However, the frequent lodging during the growing period severely affect the high yielding potential and the quality of the grain and forage of oat. Therefore, we used the lodging-resistant variety LENA and the lodging-sensitive variety QY2 as materials, implementing four different planting densities: 2.25×106 plants/ha (D1), 4.5×106 plants/ha (D2), 6.75×106 plants/ha (D3), and 9×106 plants/ha (D4). At the appropriate growth and development stages, we assessed agronomic traits, mechanical characteristics, biochemical compositions, yield and its components. The study investigated the impact of planting density on the growth, lodging, and yield of oat, as well as their interrelationships. Additionally, we identified the optimal planting density to establish a robust crop structure. The research aims to contribute to the high-yield and high-quality cultivation of oat. We observed that with increasing planting density, plant height, grass and grain yields of both varieties first increased and then decreased; root fresh weight, stem diameter, stem wall thickness, stem puncture strength, breaking strength, compressive strength, lignin and crude fiber contents, and yield components decreased; whereas the lodging rate and lodging coefficient increased. Planting density affects lodging by regulating plant height, height of center of gravity, stem wall thickness, internode length, and root fresh weight of oat. Additionally, it can impact stem mechanical strength by modulating the synthesis of lignin and crude fiber, which in turn affecting lodging resistance. Plant height, height of center of gravity, stem wall thickness, internode length, root fresh weight, breaking strength, compressive strength, lignin and crude fiber content, single-plant weight, grain yield and 1,000-grain weight can serve as important indicators for evaluating oat stem lodging resistance. We also noted that planting density affected grain yield both directly and indirectly (by affecting lodging); high density increased lodging rate and decreased grain yield, mainly by reducing 1,000-grain weight. Nonetheless, there was no significant relationship between lodging and grass yield. As appropriate planting density can increase the yield while maintaining good lodging resistance, in this study, 4.5×106 plants/ha (D2) was found to be the best planting density for oat in terms of lodging resistance and grass and grain yield. These findings can be used as a reference for oat planting.

Development of Antifungal Packaging From Low‐Density Polyethylene With Essential Oil of Oregano and Potassium Sorbate

ABSTRACTAntimicrobial low‐density polyethylene (LDPE) films were developed by adding 0%, 0.5%, 1.0%, 2.5% and 5.0% (w/w) of Mexican oregano essential oil (OEO) or potassium sorbate (PS) as a positive antifungal control to inhibit the growth of Penicillium expansum, Penicillium citrinum and Aspergillus niger in vitro. Three methods of adding OEO in LDPE were evaluated; the best OEO yield in film was achieved when OEO was incorporated after laminating (88%); otherwise, when added into cool‐melting resin, OEO lost up to 91.5% from LDPE and completely volatilized (>99%) when combined with the resin before melting. PS yields in LDPE film were > 88% when incorporated into cool‐melted resin. Antimicrobial films with 2.5% or 5.0% (w/w) OEO or PS delayed the growth of P. expansum and P. citrinum for up to 4–5 days, and for A. niger, only films with 5.0% of OEO retarded its growth for 5 days. The modified Gompertz model was used to describe mould growth response, obtaining the parameters A (maximum growth), μm (maximum growth rate) and λ (lag phase), which correctly fit the data. P. citrinum was the most sensitive mould, and A. niger was the most resistant to the tested antimicrobials. The addition of antimicrobial agents significantly (p < 0.05) impacted the physical and mechanical properties of the LDPE films, wherein thickness and puncture strength were increased, and the colour changed (reducing the transparency and promoting the yellowness). In contrast, the water vapour transmission rate was dropped only by incorporating PS.

The effect of phenolics from bergamot juice powder extracted with different solvents on the physicochemical and antibacterial properties of chitosan films

Due to its bitterness, bergamot juice has no practical use, but it is a rich source of phenolic compounds, which provide significant antibacterial and antioxidant activity. In this study, extracts were prepared from spray-dried bergamot juice powder using acetone, dimethylsulfoxide, ethanol, and distilled water. These extracts were then incorporated into chitosan film matrices at 1%, 2%, and 3% (v/v) ratios. The analysis revealed that adding extracts generally created a barrier against light in the chitosan films, improved color, increased moisture content and water solubility, and caused significant enhancements in antioxidant activity, total phenolic content, thickness, mechanical strength, and provided substantial antibacterial activity against both Gram(+) and Gram(-) bacteria. The most effective modification of film properties was achieved by adding 3% acetone extract, while the 1% distilled water extract resulted in the least improvement. Specifically, the transparency, opacity, chroma, moisture, solubility, antioxidant activity, total phenolic content, thickness, puncture strength, and elasticity of pure chitosan film were 4.3–73.8%, 1.13 abs/mm, 15.61, 25.35%, 41.28%, 20.66%, 919.53 ppm, 1.09 N/mm2, 132.44%, and 0.07 mm, respectively. Meanwhile, those of the film with 3% acetone extract were 0.2–70.10%, 2.07 abs/mm, 36.34, 42.33%, 54.64%, 46.13%, 2915.72 ppm, 3.34 N/mm2, 142.68%, and 0.15 mm, respectively. The pure chitosan film exhibited no antibacterial effect against Gram(+) and Gram(-) bacteria, but adding extract enhanced antibacterial activity. Moreover, SEM analysis revealed distinct structural differences in the films, including varying porosity and phenolic distribution. At the same time, FTIR spectra demonstrated shifts in chemical composition and bonding within the films.

Nanofibrillated pulps from Amazonian species as a potential raw material for ecological packaging

Abstract Using cellulosic micro/nanofibrils (MFC/NFC) in developing films for coatings and packaging has aroused industrial interest to replace plastic. This study proposes functionalizing packaging films composed of hybrid suspensions of 80 % titica vine (Heteropsis flexuosa) and 20 % Pinus to improve their mechanical properties. The MFC/NFC were produced by mechanical fibrillation and adding proportions of 1, 2.5, and 5 % of nanolignin, vegetal tannin, and synthetic termite saliva. Both suspensions had concentrations of 1 % (w/w). The MFC/NFC were evaluated for energy consumption, microstructural, and stability, while the films were for physical, optical, barrier, and mechanical properties. Films with nanolignin 2.5 % obtained lower WVP and degradation in water, with greater hydrophobicity and puncture strength. The treatment with tannin 1 % obtained higher density and lower porosity, while termite saliva 1 % presented higher tensile strength at around 53.1 MPa. The additives improved the quality index of the MFC/NFC (>51.1 points). It is concluded that adding different binders can help expand the use of MFC/NFC. New studies are essential to seek pre-treatments or alternative fibrillation methods to increase their application and efficiency for fiber cell wall fibrillation, in addition to the need for a deeper analytical understanding of the interactions of additives with cellulose.

Effects of polyol and surfactant plasticisers on lyophilised rice starch wafers for buccal drug delivery

Rice starch is a promising biopolymer for buccal formulations but typical oven drying may promote starch retrogradation that affects mechanical properties. Hence, lyophilisation was proposed here to improve starch product's stability. This study aims to investigate the effects of plasticisers (sorbitol and Tween® 80, T80) on the characteristics and drug release profiles of lyophilised rice starch wafers incorporated with propranolol hydrochloride. The wafers were prepared by lyophilising starch mixture (5%w/v) with plasticiser (0.2 and 0.3 g/g) and drug (10, 20, 30%w/w). Control wafers exhibited loose layers with rough wrinkled surface. Sorbitol resulted in a dense structure with higher puncture strength (PS) but lower water absorption capacity (WAC) while T80 loosened the flakes that reduced PS and increased WAC. Drug inclusion decreased PS and increased WAC of unplasticised wafers. T80-plasticised wafers with drug had a lower PS and higher WAC than sorbitol-plasticised wafers. Particularly, T80-plasticised wafers achieved outstandingly high PS and the lowest WAC at 30%w/w drug. Drug dissolution of wafers relied mainly on the drug crystallinity and WAC at 10 and 30%w/w drug. Plasticisers reduced and increased drug dissolution at 10 and 20%w/w drug, respectively. This study highlights the potential of lyophilisation in preparing rice starch wafers for buccal delivery.

Virtues of Cold Isostatic Pressing for Preparation of All-Solid-State-Batteries with Poly(Ethylene Oxide).

All-solid-state-batteries (ASSBs) necessitate the preparation of a solid electrolyte and an electrode couple with individually dense and compact structures with superior interfacial contact to minimize overall cell resistance. A conventional preparation method of solid polymer electrolyte (SPE) with polyethylene-oxide (PEO) generally consists in employing uni-axial hot press (HP) to densify SPE. However, while uni-axial press with moderate pressure effectively densifies PEO with Li salts, excessive pressure also unavoidably results in perpendicular elongation and deformation for polymer matrix. In this research, to overcome this limitation for the uni-axial press technique, a cold isostatic press (CIP) is applied to the fabrication of ASSB with PEO and LiFePO4 . CIP effectively and uniformly applies pressure as high as 500 MPa without deformation. Characterizations confirm that CIP treated SPE has enhanced mechanical puncture strength, increasing from 499.3±22.6 to 539.3±22.6 g, and ionic conductivity, increasing from 1.04×10-4 to 1.91×10-4 S cm-1 at 50 °C. ASSB treated by CIP demonstrates remarkably enhanced rate capability and cyclability compared with the cell processed by HP, which is further evidenced by improvement of the apparent Li ion diffusion constant based on Sand equation analysis. The improvement enabled by CIP treatment originates from the superior interface uniformity between electrodes and SPE and from the densification of the LiFePO4 and SPE composite electrode.

Evaluation of the Tensile and Puncture Properties of Geotextiles Influenced by Soil Moisture under Freezing Conditions.

Freezing conditions under different humidity will influence the mechanical properties of geotextiles, leading to the gradual fracture of geotextiles. It brings hidden danger to the whole isolation, reinforcement and protection of rock and soil. It is particularly important to study the tensile and puncture properties of geotextiles considering low temperature and moisture content. In this paper, a series of tensile and puncture tests of geotextiles are performed under different low temperatures (0, -3, -6, -9, and -12 °C) and at different moisture content levels (0, 5, 10, 30, 50, and 80%). From the microscopic perspective, the failure mechanism considering the low temperature and moisture content was explained comprehensively. Experimental results indicate that with a decrease in freezing temperature, the tensile strength of geotextiles increases as a parabolic function while the elongation at failure decreases as an exponential function. Additionally, the puncture strength of geotextiles presented a parabolic increase with the decreasing temperature. Under the freezing temperature environment, the higher moisture content of geotextiles can generate a higher puncture strength increment. This research contributes to a more comprehensive understanding of the tensile and puncture properties of geotextile materials considering low temperature and moisture content. It can provide important guidance for the design of slopes, the reinforcement of earthen dams, and roadbed reinforcement with geotextiles in cold regions.

Impact of Nanoclays Addition on Chickpea (Cicer arietinum L.) Flour Film Properties.

Chickpea flour is an affordable natural blend of starch, proteins, and lipids, which can create films with suitable properties as an eco-friendly packaging material. Nanoclays' incorporation into natural biopolymers enhances the barrier properties of the resulting nanocomposites, so they could improve the properties of flour films. The objective of this work was to assess the influence of three types of nanoclays (halloysite, bentonite, and Cloisite 20A) at two concentrations on the characteristics of chickpea flour films. In general terms, when the lowest dose (5%) was added, no or very slight significant differences with the control were observed in most parameters, except for thermal stability and opacity, which increased, and solubility, which decreased. At the highest concentration (10%), films containing any of the nanoclays demonstrated greater thermal stability, opacity, and rigidity while being less soluble than those without nanofillers. Bentonite exhibited superior film structure distribution compared to other nanoclays. At the highest concentration, it had the most significant impact on modifying the properties of chickpea flour films, increasing their tensile and puncture strengths while decreasing elasticity and water vapor permeability. The incorporation of nanoclays into chickpea flour films could be a useful technique to enhance their properties.

Dressing Paraffin Wax/Boron Nitride Phase Change Composite with a Polyethylene "Underwear" for the Reliable Battery Safety Management.

Phase change material (PCM) can provide a battery system with a buffer platform to respond to thermal failure problems. However, current PCMs through compositing inorganics still suffer from insufficient thermal-transport behavior and safety reliability against external force. Herein, a best-of-both-worlds method is reported to allow the PCM out of this predicament. It is conducted by combining a traditional PCM (i.e., paraffin wax/boron nitride) with a spirally weaved polyethylene fiber fabric, just like the traditional PCM is wearing functional underwear. On the one hand, the spirally continuous thermal pathways of polyethylene fibers in the fabric collaborate with the boron nitride network in the PCM, enhancing the through-plane and in-plane thermal conductivity to 10.05 and 7.92Wm-1 K, respectively. On the other, strong polyethylene fibers allow the PCM to withstand a high puncture strength of 47.13 N and tensile strength of 18.45MPa although above the phase transition temperature. After this typical PCM packs a triple Li-ion battery system, the battery can be promised reliable safety management against both thermal and mechanical abuse. An obvious temperature drop of >10°C is observed in the battery electrode during the cycling charging and discharging process.

Puncture Resistance and UV aging of Nanoparticle-Loaded Waterborne Polyurethane-Coated Polyester Textiles.

The goal of this research was to investigate the effect of different types of nanoparticles on the UV weathering resistance of polyurethane (PU) treatment in polyester-based fabrics. In this regard, zinc oxide nanoparticles (ZnO), hydrophilic silica nanoparticles (SiO2 (200)), hydrophobic silica nanoparticles (SiO2 (R812)), and carbon nanotubes (CNT) were mixed into a waterborne polyurethane dispersion and impregnated into textile samples. The puncturing resistance of the developed specimens was examined before and after UV-accelerated aging. The changes in chemical structure and surface appearance in nanoparticle-containing systems and after UV treatments were documented using microscopic pictures and infrared spectroscopy (in attenuated total reflectance mode). Polyurethane impregnation significantly enhanced the puncturing strength of the neat fabric and reduced the textile's ability to be deformed. However, after UV aging, mechanical performance was reduced both in the neat and PU-impregnated specimens. After UV treatment, the average puncture strength of all nanoparticle-containing systems was always greater than that of aged fabrics impregnated with PU alone. In all cases, infrared spectroscopy revealed some slight differences in the absorbance intensity of characteristic peaks for polyurethane polymer in specimens before and after UV rays, which could be related to probable degradation effects.

The flexible stab‐resistant composite membrane made by thermoplastic polyurethane filled with modified nanoparticles

AbstractThermoplastic polyurethane (TPU) has good elasticity and tear resistance, and is often applied in the field of flexible puncture resistance although the puncture resistance of pure TPU is limited. In this paper, silica powder (SiO2) and styrene butadiene rubber powder (SBR) with different concentrations were used as fillers to reinforce the TPU matrix respectively. To overcome the problem of poor interfacial compatibility between filler and matrix, the silane coupling agent r‐Aminopropyltrieth oxysilanee (KH550) was selected to modify the particles. The compatibility of particles and matrix, the puncture properties and tensile properties of composites were assessed by FTIR, TEM, SEM, tensile testing, and needle puncture testing. Further, the tensile and puncture properties of composites with different types and concentrations of particles were systematically compared and analyzed to find optimal parameters. The results show that the best modification effect is gained when the mass ratio of KH550 and nanoparticles is 0.85:1 and the specific puncture strength of TPU membranes incorporated modified SiO2 or SBR nanoparticles can be increased by up to 106.4% and 85% respectively compared to pure TPU membrane.

Effect of chemical treatment on physical, mechanical, and morphological characteristics of sisal geotextile

This study explores the effect of chemical treatment on the physical, mechanical, and morphological properties of two kinds of sisal geotextiles treated with potassium hydroxide and coated with bitumen emulsion. Physical characteristics like mass per unit area, yarn properties, thickness, water absorption and mechanical properties, including tensile, tearing, and puncture strength, were examined. The findings showed significant enhancements in tensile strength (up to 54.90%), tearing strength (up to 103.81%), and puncture strength (up to 32.2%) of emulsion-coated untreated, emulsion-coated alkali-treated and alkali-treated geotextiles, respectively. Furthermore, the alkali-treated emulsion-coated geotextile had the highest mass per unit area with the least water absorption. Morphological, elemental, and crystallographic analyses complemented these outcomes.

Effect of chitosan-based bio coating on mechanical, structural and physical characteristics of microfiber based paper packaging: An alternative to wood pulp/plastic packaging

Limnocharis flava is a noxious aquatic weed that poses a threat to paddy cultivation. The high cellulose and low lignin contents in this plant make it a potential raw material for papermaking. Against this backdrop, this study was taken up to develop Limnocharis flava (LF) based sheets containing natural fibres from Banana (B), Pineapple (P), and Rice Straw (RS) as reinforcing agents. The influence of carboxymethyl cellulose (CMC) as a binder on the LF-based sheets was also studied. To enhance the mechanical and moisture resistance properties, a chitosan coating was provided to the sheets. Analytical tests for mechanical properties, water barrier properties, functional groups, structure and microstructure, thermal properties and biodegradability were performed. Among the samples, LF + B showed the highest tensile strength (34.86 Mpa) and bursting strength (13.055 kg/cm2), while LF + R had higher puncture and tearing strengths. Chitosan coating was found to enhance the sheets and improve the water barrier properties mechanically. The contact angle of LF + B increased from 91.6° to 110.65°, while the water vapour transmission rate of LF reduced from 532.18 to 404.47 on providing chitosan coating. The significant interactions of reinforcing agents were confirmed by the results of FTIR and that of the coating by the SEM micrographs. The LF-based sheets were also found to have decent thermal stability. The high value of the crystallinity index in LF + R samples supported their remarkable mechanical properties. This study proclaims the notable suitability of Limnocharis flava in manufacturing paper for packaging applications.

Effect of Birch Sap as Solvent and Source of Bioactive Compounds in Casein and Gelatine Films.

Birch sap consists of a natural water-based solution with valuable compounds such as minerals, sugars, organic acids and phenolic compounds that can be used advantageously in the preparation of edible films. In this study, gelatine- and casein-based films were prepared using birch sap as biopolymer solvent and source of bioactive compounds with the aim of developing new bioactive materials for food packaging. The physical, mechanical, barrier, antioxidant and iron-chelating properties of the obtained films were investigated. Birch sap enhanced the mechanical properties of the films by increasing puncture strength and flexibility, as well as their ultraviolet-visible light barrier properties. In addition, the presence of bioactive compounds endowed the birch sap films with an antioxidant capacity of almost 90% and an iron-chelating capacity of 40-50% with respect to the control films. Finally, to test these films as food packaging material, a photosensitive curcumin solution was packed and exposed to ultraviolet light. Tested films were able to protect curcumin against photodegradation, and the presence of bioactive compounds inside the birch-sap-enriched materials offered an additional 10% photoprotective effect compared to control films. Results showed the potential of birch sap as an environmentally friendly biopolymer solvent and plasticizer that can improve the mechanical and photoprotective properties of the prepared materials.