Modification Of Fibers Research Articles

Beyond the Surface: A Methodological Exploration of Enzyme Impact along the Cellulose Fiber Cross-Section.

Despite the wide range of analytical tools available for the characterization of cellulose, the in-depth characterization of inhomogeneous, layered cellulose fiber structures remains a challenge. When treating fibers or spinning man-made fibers, the question always arises as to whether the changes in the fiber structure affect only the surface or the entire fiber. Here, we developed an analysis tool based on the sequential limited dissolution of cellulose fiber layers. The method can reveal potential differences in fiber properties along the cross-sectional profile of natural or man-made cellulose fibers. In this analytical approach, carbonyl groups are labeled with a carbonyl selective fluorescence label (CCOA), after which thin fiber layers are sequentially dissolved with the solvent system DMAc/LiCl (9% w/v) and analyzed with size exclusion chromatography coupled with light scattering and fluorescence detection. The analysis of these fractions allowed for the recording of the changes in the chemical structure across the layers, resulting in a detailed cross-sectional profile of the different functionalities and molecular weight distributions. The method was optimized and tested in practice with LPMO (lytic polysaccharide monooxygenase)-treated cotton fibers, where it revealed the depth of fiber modification by the enzyme.

Novel Biocomposite of Starch and Flax Fiber Modified with Tannic Acid with Biocidal Properties.

The purpose of this paper was to develop novel biocomposites with biocidal properties in microorganisms, with enhanced mechanical strength and hydrophobicity as well as with increased biodegradation rates. The main idea and the novelty of this work was to use cross-linking compounds and, at the same time, biocidal compounds-natural compounds of plant origin with biocidal properties. The authors assumed that the modification of flax fiber by natural plant compound will reduce the hydrophilicity of novel biocompositie. Biopolymer based on thermoplastic starch reinforced with flax fibres modified with tannic acid (TA) was prepared by extrusion and injection molding processes. The effects of TA modification on the mechanical and structural properties of biocomposites were analyzed through DMA, tensile tests, DSC, and TG. The biocidal and wettability properties of the biocomposites were investigated. The article also discusses the outcomes of research conducted on the structural characteristics and rates of the biodegradation of biocomposites.

Enhancement of Flexural Strength in Fiber–Cement Composites through Modification of Sisal Fiber with Natural Rubber Latex and Expanded Perlite

This study presents a novel approach in enhancing the flexural strength of sisal fiber cement composites by employing a dual coating technique with natural rubber latex and expanded perlite to the sisal fibers. The effects of different fiber content (0.25, 0.5, 0.75, 1, 1.25, and 1.5 wt%) and fiber length (1, 2, and 3 cm) on the physical and mechanical properties of sisal fiber cement were also studied. The physical properties, including bulk density and water absorption, were evaluated via the Archimedes method. Flexural strength was measured using the 3-point bending method, and microstructure was observed using a scanning electron microscope (SEM) and an optical microscope (OM). As the fiber content and length increase, the bulk density of the sisal fiber cement decreases. However, composites utilizing coated fibers consistently exhibit a higher bulk density than those utilizing uncoated fibers, attributed to enhanced adhesion and reduced porosity. The water absorption of sisal fiber cement increases with fiber content, but it is mitigated by the natural rubber latex coating, which prevents fiber–water absorption, and by expanded perlite, which reduces voids in the matrix. Composites containing coated fibers consistently exhibit superior flexural strength compared to those with uncoated fibers. The highest flexural strength values of 5.58 MPa were observed in composites utilizing 3 cm of coated fiber with 0.25 wt% fiber content. Microstructure analysis reveals a well-bonded interface in coated fibers, emphasizing the positive impact of coating on mechanical performance. The incorporation of coated sisal fibers effectively improves adhesion, water resistance, and flexural strength, offering sustainable and durable construction materials. The achieved results can serve as the guidelines for the development of a high-performance bio-based construction materials with improved durability and reduced environmental impact.

Modification of pea dietary fibre by superfine grinding assisted enzymatic modification: Structural, physicochemical, and functional properties

Using the optimal extraction conditions determined by response surface optimisation, the yield of soluble dietary fibre (SDF) modified by superfine grinding combined with enzymatic modification (SE-SDF) was significantly increased from 4.45 % ± 0.21 % (natural pea dietary fibre) to 16.24 % ± 0.09 %. To further analyse the modification mechanism, the effects of three modification methods–superfine grinding (S), enzymatic modification (E), and superfine grinding combined with enzymatic modification (SE)–on the structural, physicochemical, and functional properties of pea SDF were studied. Nuclear magnetic resonance spectroscopy results showed that all four SDFs had α- and β-glycosidic bonds. Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy results showed that the crystal structure of SE-SDF was most severely damaged. The Congo red experimental results showed that none of the four SDFs had a triple-helical structure. Scanning electron microscopy showed that SE-SDF had a looser structure and an obvious honeycomb structure than other SDFs. Thermogravimetric analysis, particle size, and zeta potential results showed that SE-SDF had the highest thermal stability, smallest particle size, and excellent solution stability compared with the other samples. The hydration properties showed that SE-SDF had the best water solubility capacity and water-holding capacity. All three modification methods (S, E, and SE) enhanced the sodium cholate adsorption capacity, cholesterol adsorption capacity, cation exchange capacity, and nitrite ion adsorption capacity of pea SDF. Among them, the SE modification had the greatest effect. This study showed that superfine grinding combined with enzymatic modification can effectively improve the SDF content and the physicochemical and functional properties of pea dietary fibre, which gives pea dietary fibre great application potential in functional foods.

The effect of interfacial properties of PBO fiber surface modified by oxygen plasma on quasi-static and dynamic mechanical properties of monofilament composites

PBO(p-phenylene benzobisoxazole) fibers have great application potentials in various engineering fields while the excessively smooth surface hinders their property to a large extent. In present work, the surface of PBO fiber was modified by oxygen plasma treatment with different power and time, and the epoxy resin composite before and after PBO fiber modification was prepared. The results show that the O/C ratio increases with the introduction of carboxyl group on the surface of PBO fiber. With the increase of plasma treatment power and time, the surface roughness of the fiber surface increases first and then decreases. When the treatment time of 5 minutes under 150 W, the IFSS increases from 21.01 MPa to 56.60 MPa, reaching the optimum property. After modification, the maximum strength of monofilament fiber decreases slightly under quasi-static and dynamic conditions. The results in present work can provide reference for the subsequent structural design of overall composite materials.

Enhanced mechanical qualities of sericin‐removed silk by direct feeding of silkworms with cellulose nanofiber

AbstractRecently, the modification of silkworm silk fibers (SFs) by adding fillers has been investigated. Previously, we have reported that SFs obtained from silkworms fed diets supplemented with 5 wt.% cellulose nanofiber (CNF) and whose surface was covered with sericin exhibited excellent tensile properties. On the other hand, to use SF in silk products, the sericin must be removed, and it is necessary to ensure that CNF‐enriched silkworm SFs with the sericin removed (i.e., fibroin) exhibit high tensile properties. Therefore, this study evaluated the tensile properties of sericin‐removed SF obtained from silkworms fed a CNF diet. The results showed that the average CNF with SF—near 7.5 wt.% exhibited high mechanical properties. Adding CNF to the silkworm diet did not affect their growth and cocoon yield. The analysis of the SF microstructure confirmed that CNF is a fibrous material on the surface of fibroin. Kelly‐Tyson's equation suggested that almost all of the CNF in fibroin contributed to the increased tensile strength.

Redirect Tropism of Fowl Adenovirus 4 Vector by Modifying Fiber2 with Variable Domain of Heavy-Chain Antibody.

The variable domain of a heavy-chain antibody (VHH) has the potential to be used to redirect the cell tropism of adenoviral vectors. Here, we attempted to establish platforms to simplify the screening of VHHs for their specific targeting function when being incorporated into the fiber of adenovirus. Both fowl adenovirus 4 (FAdV-4) and simian adenovirus 1 (SAdV-1) have two types of fiber, one of which is dispensable for virus propagation and is a proper site for VHH display. An intermediate plasmid, pMD-FAV4Fs, was constructed as the start plasmid for FAdV-4 fiber2 modification. Foldon from phage T4 fibritin, a trigger for trimerization, was employed to bridge the tail/shaft domain of fiber2 and VHHs against human CD16A, a key membrane marker of natural killer (NK) cells. Through one step of restriction-assembly, the modified fiber2 was transferred to the adenoviral plasmid, which was linearized and transfected to packaging cells. Five FAdV-4 viruses carrying the GFP gene were finally rescued and amplified, with three VHHs being displayed. One recombinant virus, FAdV4FC21-EG, could hardly transduce human 293 or Jurkat cells. In contrast, when it was used at a multiplicity of infection of 1000 viral particles per cell, the transduction efficiency reached 51% or 34% for 293 or Jurkat cells expressing exogenous CD16A. Such a strategy of fiber modification was transplanted to the SAdV-1 vector to construct SAdV1FC28H-EG, which moderately transduced primary human NK cells while the parental virus transduced none. Collectively, we reformed the strategy of integrating VHH to fiber and established novel platforms for screening VHHs to construct adenoviral vectors with a specific tropism.

Improving dispersion of basalt fiber with polyethylene glycol and effect of coupling agent

ABSTRACT Basalt fibers were widely used as reinforcing matrix materials because of their thermal and chemical stability and environmental friendliness. The properties of composite materials were affected by the interaction between the basalt fibers and matrix materials. Surface modification of basalt fibers and the dispersion property have become key points of research in recent years. This study focuses on the impact of a dispersant on surface modification. Basalt fibers were dispersed by polyethylene glycol (PEG) before modification with 3-aminopropyltriethoxysilane (KH550), which significantly increased the surface roughness, thus increasing the surface area and facilitating mechanical bonding. The morphology, structure, and composition were characterized via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy analysis (XPS), respectively. The distribution characteristics of fiber were evaluated by the response surface method. When the mass fraction of PEG was 0.5 wt.%, the modification time was 2.5 hours, and the modification temperature was 60°C, the fiber dispersion degree in KH550 solution reached 83%. The grafting degree test indicates that the weight of the grafting increased to 6.67 times that of the undispersed basalt fibers. This enhancement allowed for greater grafting of the KH550, thereby optimizing the effect of modified fibers.

Shaping sustainable pathways: Enhancing mechanical properties of biocomposite through tannic acid treatment of flax fabrics

Biocomposites developed using natural fibers serve as a sustainable alternative to synthetic composite materials. However, narrowing the performance gap between synthetic composites and biocomposites requires serious efforts. A promising approach is the modification of natural fibers using various chemical treatments. This paper investigates the potential of tannic acid (TA) treatment as a sustainable approach to enhance mechanical performance and reduce moisture absorption of flax fabric-reinforced biocomposites. The methodology involves the treatment of flax woven fabric with tannic acid, a naturally occurring polyphenolic compound, followed by the fabrication of biocomposite using a green epoxy matrix. The variables studied during treatment are TA concentration and processing time. Characterization of untreated and treated flax fabric and its composites was done using various analytical techniques such as FTIR spectroscopy, moisture absorption and mechanical testing (tensile strength, flexural strength, and impact resistance). FTIR spectroscopy of TA-treated flax confirmed attachment of aromatic rings and carbon double bond formation, thus serving for properties enhancement. The mechanical characterization of composites showed that properties are enhanced up to an optimum limit of concentration and processing time i.e., 1 % concentration and 30 min of processing. Moisture absorption of the TA-treated composite also reduced significantly as compared to untreated composites. These findings contribute towards the advancement in sustainable biocomposites and pave the way for their utilization in various applications.

Role of dietary fiber and lifestyle modification in gut health and sleep quality.

Dietary fiber has an immense role in the gut microbiome by modulating juvenile growth, immune system maturation, glucose, and lipid metabolism. Lifestyle changes might disrupt gut microbiota symbiosis, leading to various chronic diseases with underlying inflammatory conditions, obesity, and its associated pathologies. An interventional study of 16 weeks examined the impact of psyllium husk fiber with and without lifestyle modification on gut health and sleep quality in people with central obesity (men = 60 and women = 60), those aged from 40 to 60 years, those having WC ≥ 90 cm (men) and WC ≥ 80 cm (women), and no history of any chronic disease or regular medication. The participants were subgrouped into three intervention groups, namely, the psyllium husk fiber (PSH) group, the lifestyle modification (LSM) group, and the LSM&PSH group and control group with equal gender bifurcation (men = 15 and women = 15). A 24-h dietary recall, gastrointestinal tract (GIT) symptoms, and sleep quality analysis data were collected on validated questionnaires. The analyses of variance and covariance were used for baseline and post-intervention, respectively. Student's t-test was applied for pre- and post-intervention changes on the variable of interest. The intervention effect on GIT health was highly significant (P < 0.001). The mean GIT scores of the LSM, PSH, and LSM&PSH groups were 2.99 ± 0.14, 2.49 ± 0.14, and 2.71 ± 0.14, respectively, compared to the mean GIT scores of the control group. No significant (P = 0.205) effect of either intervention was observed on sleep quality. The study concluded that psyllium husk fiber significantly improved the GIT symptoms, while no significant effect of the intervention was observed on sleep quality analysis.

TRENDS, PROBLEMS AND PROSPECTS FOR TEXTILE PRODUCTION IN FUTURE

Demand for textile products is increasing and the adequate supply of textile fibres may become a major problem in coming years because of both changes in world climatic conditions affecting supply of natural fibre sources and because of financial and economic problems. Longer summers and warmer days will support fashion trends for light weight and casual wear. Thus, research on energy saving methods and processes, on fibre modification and structuring of yarns and fabrics will be beneficial.

Bamboo fiber reinforced poly (acrylonitrile-styrene-acrylic)/chlorinated polyethylene via compabilization

In the quest to enhance the performance of natural fiber-reinforced polymer composites, achieving optimal dispersion of fiber materials within a polymeric matrix has been identified as a key strategy. Traditional approaches, such as the surface modification of natural fibers, often necessitate the use of additional synthetic chemical processes, presenting a significant challenge. In this work, taking poly (acrylonitrile–styrene–acrylic) (ASA) and bamboo fiber (BF) as a model system, we attempt to use the elastomer-chlorinated polyethylene (CPE) as a compatibilizer to tailor the mechanical properties of ASA/CPE/BF ternary composites. It was found that increasing CPE content contributed to more remarkable reinforcing efficiency, where composite with 15 phr CPE exhibited a nearly four-fold increase in reinforcing efficiency of tensile strength (20 %) compared with that of composite system without CPE (4.1 %). Such improvement was ascribed to the compatibilizing effect exerted by CPE, which prevented the aggregation of BF within polymeric matrix. Surface properties suggested the stronger interface between CPE and BF compared to that between ASA and BF and thereby contributed to the compabilizing effect. Since no chemical process was involved, it is suggested that the introduction of elastomer to be a universal, green and sustainable approach to achieve the reinforcement.

Določanje obstojnosti funkcionaliziranih tekstilij na osnovi kopolimerov akrilonitrila na toplotno in toplotno-oksidativno razgradnjo

Acrylonitrile is widely used to produce carbon fibres, household textiles, artificial fur, etc. The modification of polyacrylonitrile fibres in an alkaline medium is extended in the production of textile sorbents. The scientific direction of fibre modification through surface activation using hydrogen peroxide is of scientific interest. However, the thermal and thermophysical properties of the samples are not examined. Therefore, interest arises when analysing the effect of polyacrylonitrile textile material functionalization on the resistance of fibres to thermal oxidation and thermal degradation. The study of thermogravimetry and differential thermogravimetry thermooxide of polyacrylonitrile – modified fibres is carried out using thermogravimetric analysis to research the thermal oxidation and thermal degradation of modified polyacrylonitrile fibre samples. A change in the rate of thermal oxidative-degradation in the process of functionalization was identified in this research. A change in the loss of mass of the sample under different conditions of functionalization was also identified. The total glass transition of the polyacrylonitrile was achieved by heating the polymer to 130 °C. The intensification self-regulation of the structure of the polymeric material through the formation of the mesophase was released at the temperature of around 100 °C. During the heating of the initial polyacrylonitrile textile material to the temperature of 70‒80 °C, a weakening of intermolecular contacts was observed, which led to an increase in the mobility of macromolecular segments. The temperature of 78 °С was considered to be the initial glass transition temperature Tg,t1 and Tg,t2 – 121 °С as the final temperature for the original sample. However, if the temperature exceeded 130 °C, chemical changes in the polymer occurred, in particular, the process of cyclization. The analysis of the thermogravimetry data of thermally oxidized samples resulted in the retention of the complex stepwise nature of decomposition inherent in the initial fibrous material based on acrylonitrile copolymers. The conducted analysis showed the absence of significant changes in the reasonable conditions of chemical modification and practical operation of textile materials. The physical and mechanical properties of functionalized textile materials based on acrylonitrile copolymers were studied. As a result of surface functionalization, an insignificant strength reduction of functionalized textile materials occurred.

Development and characterization of microwave‐processed linear low‐density polyethylene based sisal/jute hybrid laminates

AbstractNatural fiber‐reinforced composites are gaining significant popularity for their biodegradability and eco‐friendliness. Fiber modifications and hybridization have been used to address issues like hydrophilicity and fiber inhomogeneity. However, efficient manufacturing is still a challenge for natural fiber‐reinforced polymer composites. The present study explores the potential of microwave processing of hybrid laminates composed of sisal and jute fibers. The laminates, consisting of linear low‐density polyethylene (LLDPE) as matrix and sisal and jute as reinforcement materials were subjected to microwave processing at specific power, time, frequency, and loads. Four types of laminates with different stacking sequences: sisal‐sisal‐sisal (SSS), sisal‐jute‐sisal (SJS), jute‐sisal‐jute (JSJ), and jute‐jute‐jute (JJJ) were developed. The developed composites showed ~3% void content, with the SJS and JSJ composite having the least and highest void content, respectively. The SJS composite showed the highest tensile and flexural strength of 15.27 and 20.40 MPa, respectively, out of all the configurations and an improvement of 42% and 85% over pure LLDPE. Hybrid composites having high‐strength fibers in the skin layer exhibited superior mechanical properties. Microscopic examination of the fractured specimens revealed that fiber pull‐out and fiber breakage were the primary failure mechanisms of failure. Lateral failure due to delamination between matrix and fiber was predominant with grip and gauge regions as frequent failure points. The incorporation of sisal and jute fiber reinforcement into the polymers doesn't change the thermal stability of the fabricated composites significantly. The above results show that microwave‐assisted processing is a promising method for producing natural fiber‐reinforced hybrid polymer composites.Highlights Development of hybrid laminates using microwave energy at 2.45 GHz. The mechanism of microwave‐based processing of polymer composites has been discussed. Effect of layering sequence on mechanical and thermal properties of the developed composite. Assessment of tensile strength with morphology, flexural strength and thermo‐gravimetric analysis.

Surface modification of polytetrafluoroethylene (PTFE) fibers through methyl methacrylate (MMA) polymerization for self-lubricating composites

PTFE fibers exhibit strong inertia and possess restricted interfacial compatibility with resin, thereby constraining the application of PTFE self-lubricating composites. To address this issue, PTFE-g-MMA fibers were synthesized by grafting MMA onto the surface of PTFE fibers using high-energy irradiation and chemical grafting techniques, resulting in the enhancement of the tribological properties (the friction coefficient has been reduced by approximately 42.2% and the wear rate has been reduced by about 87.9%) and mechanical properties (the interlaminar shear strength (ILSS) experienced a substantial increase of approximately 45.8%) of the composites. The influence of grafting modification on the formation of PTFE transfer films and the effect of modification time on the tribological properties of composites were investigated systematically. The results indicated that graft modification disrupted the C–F bond of PTFE and promoted the formation of metal-chelated carboxylates, facilitating the formation of PTFE transfer films on the counter surface. This research could provide a general and feasible strategy for large-scale modification of PTFE fibers with exceptional comprehensive properties.

Modification of ramie fibre with a mixture of NaOH solution and iso-propanol solvent for enhancing its dyeing performance

Deep shade dyeing of ramie fibre is challenging due to its high degree of polymerisation, orientation, and crystallinity. The present work involved pre-treating ramie fibre with a solution containing a mixture of NaOH and alcohol in order to improve its dyeing ability. Based on the first screening results, it has been shown that iso-propanol is the optimal alcohol solvent for modifying ramie fibres with a mixture of NaOH solution, resulting in greater levels of dye exhaustion (E%), dye fixation rate (F%), total dye fixation efficiency (T%), and K/S values. Subsequently, the orthogonal array experimental technique (L16) was utilised to optimise the treatment conditions, and it was determined at a temperature of 25 °C, using a NaOH solution with a concentration of 140 g/L, a liquid ratio of 1:2 for the volume ratio of NaOH solution to iso-propanol solvent, and a treating period of 3 min. The treated samples were subjected to a range of analytical techniques, including XRD, FTIR, TGA, and SEM; these analyses conclusively verified that the samples' properties were altered due to the optimal combination treatment. The combination solution-treated samples had significantly higher barium values compared to the other samples, suggesting an ideal mercerisation treatment. The colourfastness to washing values exhibited satisfactory results for the treated samples. Besides, a handle assessment of raw ramie fabric and treated ramie fabric was conducted to enhance the practical application feasibility.

Effects of cavitation jet combined with ultrasound, alkaline hydrogen peroxide and Bacillus subtilis treatment on the properties of dietary fiber

In this study, we compared the effects of three methods on the structural, physicochemical, and functional properties of insoluble dietary fiber (IDF) in okara: cavitation jet plus ultrasonic treatment (UC), cavitation jet plus alkaline hydrogen peroxide treatment (HC), and cavitation jet plus fermentation with Bacillus subtilis (FC). Compared to UC-IDF, the two types of co-modified IDF showed significant differences in particle size and specific surface area. Structural analyses showed that HC-IDF had a porous structure and complex morphological structure, with a significant increase in the absorption peak area at around 3420 cm−1 and 1051 cm−1, and a significant decrease in thermal stability and crystallinity. Of the three treatments, HC most effectively enhanced the physicochemical and adsorption properties of IDF, including the emulsion stability (84.49% ± 3.5%), water-holding capacity (16.04 ± 0.05 g/g), glucose absorption capacity (53.17 ± 3.44 g/g), cholesterol absorption capacity (32.87 ± 0.89 mg/g), and nitrite absorption capacity (211.7 ± 0.17 μg/g). These results demonstrate the potential of HC-modified okara IDF as a valuable functional food ingredient. Therefore, the cavitation jet combined with alkaline hydrogen peroxide method has a good potential for application in the study of dietary fiber modification.

Influence of Interfacial Interaction and Composition on Fracture Toughness and Impact Properties of Carbon Fiber-Reinforced Polyethersulfone.

In this study, the interlaminar fracture toughness and impact strength of polyethersulfone reinforced with continuous carbon fibers were studied. Interlaminar fracture toughness tests were performed using the double cantilever beam method. It was shown that surface modification using the thermal oxidation method of the carbon fibers can strongly increase the interlaminar fracture toughness of the obtained composites. Thus, the maximum value reached 1.72 kJ/m2, which was 40% higher than the fracture toughness of the composites reinforced with initial carbon fibers. Moreover, fractographic analysis using a scanning electron microscope allowed us to highlight the main reasons for the dependence of fracture toughness on fiber content and surface modification conditions of the carbon fibers. It was shown that the main factor that allowed for an increase in fracture toughness was the enhanced interfacial interaction between the fibers and polymer matrix. Additionally, it was found that expectedly, there was a good correlation between interlaminar fracture toughness and interlaminar shear strength results. However, a negative influence of surface modification on the impact properties of composites was found. Such behavior occurred because of higher structural stability and lower exposure to delamination in multiple layers of the composites reinforced with the modified carbon fibers. It was found that impact energy reached ~150 kJ/m2 for the polyethersulfone-based composites reinforced with initial fibers, while the composites reinforced with modified carbon fibers showed impact energy values of only ~80 kJ/m2. Nevertheless, surface modification of carbon fibers using the thermal oxidation method can be an effective method for improving the performance properties of polyethersulfone-based composite materials.

Plant fiber-reinforced green composite: A review on surface modification, properties, fabrications and applications

Plastic pollution has become a persistent challenge globally. The extensive production of disposable plastics overwhelms the world's ability to cope with. These non-biodegradable plastics accumulating in landfills, rivers, and seas cause severe damage to wildlife and the environment. The utilization of biopolymer is a possible alternative to petroleum-based plastics. Polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), polylactic acid (PLA), poly(ε-caprolactone) (PCL), cellulose, chitin, and thermoplastic starch are mostly used biopolymers with promising properties. There are challenges too. Properties including brittleness, low thermal stability, low strength, and poor chemical barrier properties are the challenges to replacing plastics material. Reinforcing natural fibers as an alternative to non-biodegradable synthetic fiber with biopolymer matrices improves the properties of the material significantly. Flax, kenaf, jute, ramie, and hemp are a few agro-based fibers that are generally reinforced with biopolymer matrices. These composites are known as green composites. In order to create an interfacial bond between hydrophilic fiber and hydrophobic biopolymer surface modification of natural fiber is needed. There are many physical and chemical methods of surface medication which enhance roughness, wettability as well as hydrophilicity, lowers moisture absorption, improve the interfacial bond, and also enhance the tensile properties of natural fiber. The review is on the classification of biopolymers, natural fibers and their properties as well as the surface modification techniques for plant fibers. Moreover, the fabrication, mechanical and chemical properties including biodegradation of different green composites and the application of green composites, are also discussed here.

Deposition of thin films on basalt fibers surface by atmospheric pressure plasma with different siloxane precursors

In this study, surface modification of basalt fibers (BFs) utilizing atmospheric pressure plasma deposition was carried out. Using this one-step deposition approach, three siloxane precursors with different structures including methyltrimethoxysilane (MTMS), hexamethyldisiloxane (HMDSO), and tetramethoxysilane (TMOS) were deposited on BFs surface, respectively. The physicochemical properties of the thin films from three different siloxane compounds are elucidated. In comparison with MTMS-coated sample, HMDSO-coated and TMOS-coated BFs surfaces feature an improved thermal insulation performance. The results demonstrate that atmospheric pressure plasma deposition is an efficient approach to modify flexible materials surface with improved thermal insulation. Moreover, it provides a reference to decide which precursor type is preferred for certain applications.