Fiber Surface Research Articles

Ultrasonic-assisted alkali hydrolysis of polyethylene terephthalate fabric and its effect on the microstructure and dyeing properties of fibers

Abstract In this study, ultrasound energy was applied to assist the alkali hydrolysis of polyethylene terephthalate (PET) fabric, and then, the results were compared with those of the mechanical oscillating method, which was used as the control. The effects of various factors such as the sodium hydroxide concentration, the dosage of dodecyl dimethyl benzyl ammonium chloride (DDBAC), and the frequency on the weight loss of the PET fabrics were systematically investigated. The surface appearance and microstructures of the treated fibers with different methods were analyzed using a scanning electron microscope and X-ray diffraction, respectively. The results showed that DDBAC played a prominent accelerating role in the hydrolysis of the PET polymer, and the frequency had a great influence on the weight loss of the PET fabric. Ultrasound with a frequency of 60 kHz showed a similar decomposition rate as the control, resulting in similar weight loss, which was the highest value among the three frequencies (20, 60, and 80 kHz). In addition, the application of ultrasonic energy led to more pits on the fiber surface, a smaller average grain size, and decreased crystallinity of the treated fibers, while the mechanical oscillating method resulted in slightly increased crystallinity. By comparing the K/S value of the dyed fabrics with two commercial disperse dyes, we found that the treatment method had no obvious correlation with the color depth of the treated fabric.

Pd/TiO2 decorated carbon fibers as an efficient anode catalyst for methanol electro‐oxidation

AbstractIn this study, Pd/TiO2 decorated carbon nanofibers (Pd/TiO2@CNFs) and Pd@CNFs were prepared by the impregnation method for application in direct methanol fuel cells (DMFCs). Pd and TiO2 particles were supported on the surface of carbon fibers. Noticeably, When the mass fraction of PdCl2 added is 4%, the Pd@CNFs catalyst (Pd‐4@CNFs) showed higher electrocatalytic activity and stability, which were about 28.4 and 13.2 times higher than those of commercial Pd/C catalyst, respectively. On the basis of Pd‐4@CNFs catalyst, TiO2 with a mass fraction of 10% was added to produce Pd/TiO2@CNFs catalyst (Pd‐4/TiO2‐10@CNFs). The electrocatalytic activity of Pd‐4/TiO2‐10@CNFs increased to 3,850.4 A·g−1, which was 31.9 times higher than that of commercial Pd/C catalysts. These results demonstrated that the novel Pd/TiO2@CNFs catalyst is expected to be an efficient and durable catalyst for DMFC.

Characterization of Bauhinia Variegata natural fiber treated with bleaching, benzoylation, and alkalization

This study describes the physical, chemical, mechanical as well as morphological characterization of surface modified novel Bauhinia Variegata (BVR) stem fibers. Surface modifications for the fiber are accomplished with bleaching, benzoylation, and alkalization treatments. Using standard test methods, the chemical constituents of BVR fiber are evaluated like α- cellulose 62.5%, hemicellulose 10.8%, lignin18.2% and wax 0.8%. Scanning electron microscopy (SEM) was used to see how different the chemical reactions affect the fiber and SEM images confirmed the enhanced rough surface and existence of voids, along with the subtraction of unusual substances from the fiber surface. In both treated as well as untreated BVR, a Fourier-transform infrared spectroscopy (FTIR) analysis established the presence of cellulose, hemicelluloses, and lignin components. X-ray diffraction test evaluated the crystalline index for treated and raw fiber. The thermogravimetric test provides proof of enhanced thermal sustainability in the BVR upon treating chemically. The increased tensile strength and Young’s modulus upon chemical treatment confirm the improvement in the mechanical properties of the BVR fiber. The moisture absorption test revealed that the hydrophilic nature of BVR was reduced after the chemical treatment, promoting greater fiber-matrix adhesion. Presently studied BVR fiber seems to be a good substitute to the harmful man-made fibers for making of bio composites.

Investigation of Surface Modification of Bagasse Fibers: Performance of Asphalt Binders/Mixtures with Bagasse Fibers

The influence of surface modification on the properties of bagasse fibers and asphalt binders/mixtures was investigated. Bagasse fibers were modified by single, binary, and ternary methods with hydrochloric acid, sodium hydroxide, and sodium chlorite, respectively. The physical and chemical properties of bagasse fibers were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, and an adsorption test, respectively. The rheological properties of asphalt binders with bagasse fibers or lignin fibers were analyzed by the dynamic shear rheometer test and bending beam rheometer test. In addition, the performance of asphalt mixtures with bagasse fibers or lignin fibers were evaluated by a wheel rutting test, bending test at a low temperature, and water stability test, respectively. In conclusion, the hydrophilic functional groups on the fiber surface were partially eliminated by modification, facilitating the degradation of different fiber components. Furthermore, the degree of fibrillation was improved, and more interfaces with asphalt components were formed, thus enhancing the high-temperature deformation resistance of asphalt binders, but slightly impairing its low-temperature performance. Among all modification methods, the ternary composite modification exerted important influences on fiber structure, oil absorption, and rheological properties of asphalt binders, significantly enhancing the performance of asphalt mixtures. Combined with surface modification methods, bagasse fibers would be promising reinforced pavement materials.

Anti-Oxidized Self-Assembly of Multilayered F-Mene/MXene/TPU Composite with Improved Environmental Stability and Pressure Sensing Performances

MXenes, as emerging 2D sensing materials for next-generation electronics, have attracted tremendous attention owing to their extraordinary electrical conductivity, mechanical strength, and flexibility. However, challenges remain due to the weak stability in the oxygen environment and nonnegligible aggregation of layered MXenes, which severely affect the durability and sensing performances of the corresponding MXene-based pressure sensors, respectively. Here, in this work, we propose an easy-to-fabricate self-assembly strategy to prepare multilayered MXene composite films, where the first layer MXene is hydrogen-bond self-assembled on the electrospun thermoplastic urethane (TPU) fibers surface and the anti-oxidized functionalized-MXene (f-MXene) is subsequently adhered on the MXene layer by spontaneous electrostatic attraction. Remarkably, the f-MXene surface is functionalized with silanization reagents to form a hydrophobic protective layer, thus preventing the oxidation of the MXene-based pressure sensor during service. Simultaneously, the electrostatic self-assembled MXene and f-MXene successfully avoid the invalid stacking of MXene, leading to an improved pressure sensitivity. Moreover, the adopted electrospinning method can facilitate cyclic self-assembly and the formation of a hierarchical micro-nano porous structure of the multilayered f-MXene/MXene/TPU (M-fM2T) composite. The gradient pores can generate changes in the conductive pathways within a wide loading range, broadening the pressure detection range of the as-proposed multilayered f-MXene/MXene/TPU piezoresistive sensor (M-fM2TPS). Experimentally, these novel features endow our M-fM2TPS with an outstanding maximum sensitivity of 40.31 kPa−1 and an extensive sensing range of up to 120 kPa. Additionally, our M-fM2TPS exhibits excellent anti-oxidized properties for environmental stability and mechanical reliability for long-term use, which shows only ~0.8% fractional resistance changes after being placed in a natural environment for over 30 days and provides a reproducible loading–unloading pressure measurement for more than 1000 cycles. As a proof of concept, the M-fM2TPS is deployed to monitor human movements and radial artery pulse. Our anti-oxidized self-assembly strategy of multilayered MXene is expected to guide the future investigation of MXene-based advanced sensors with commercial values.

Strengthening the fiber-cement matrix interface by introducing functional groups on fiber surface

Polypropylene (PP) fiber is widely used for reinforcing cement matrix to improve its cracking resistance, but the poor interaction between two materials caused localized cracks along the fiber thus adverse effect on the fiber reinforced composites. Thus, novel methods for strengthening the fiber-cement matrix interface were proposed in this study. Amidoxime and amine functional groups were successfully grafted onto PP fiber surface through a two-step chelating procedure. XPS, FTIR, iGC-SEA and TG were employed to characterize the modified fibers, and the results verified that the surface treatment significantly improved the surface roughness, specific surface area, hydrophily and thermostability of PP fiber. Moreover, single fiber pullout, uniaxial tensile and three-point bending were conducted to assess the efficiency of surface treatment in enhancing the bonding between fiber and cement matrix, as well as the tensile and flexural strength of composites incorporating PP fibers. The bonding strength was increased by 84.15%–90.08 % and the flexural strength at 28 days was increased by 23.7%–26.4 %. The change in PP fiber surface led to densified fiber-cement matrix ITZ, enhanced chemical bonding and mechanical interlocking thus stronger interaction between fiber and cement matrix. Overall, the proposed surface treatment method is of great potential to be used in producing high performance concrete due to its easy of application and high efficiency.

Influence of CO2 laser surface treatment of basalt fibers on the mechanical properties of epoxy/basalt composites

AbstractIn fiber reinforced composite materials, the interfacial strength between the fibers and the matrix plays a key role in controlling the stress transfer and damage mechanisms of the composite. In this study, CO2 laser surface treatment of the fibers was investigated as a potential sustainable substitute for conventional chemical treatments, that can be costly and have negative environmental effects. The influence of the laser treatment on basalt fiber fabric was comprehensively investigated. The fibers were subjected to different laser power levels and characterized from a morphological and mechanical point of view. From optical and scanning electron microscopy, it was observed that the treated fibers manifested increased surface roughness along with spots of fused and bonded fibers. Individual treated fibers exhibited improved tensile properties with increased values of scale parameter (by about 21%) in the case of a laser power equal to 1.04 W/mm2, and no substantial changes in Young's modulus. The treated fibers were subsequently used in the preparation of epoxy‐based microcomposites, and microdebonding tests revealed an increase in the interfacial shear strength (IFSS) up to 8%. Therefore, this work proved that a laser surface treatment of basalt fibers is a valid alternative to conventional fiber surface modification to enhance the mechanical compatibility between fibers and matrix, and therefore to improve the mechanical performances of basalt fiber composites.Highlights Failure in composites due to weak interfacial adhesion with epoxy. CO2 laser treatment of basalt fibers to enhance interfacial adhesion. Treated fibers exhibit improved tensile properties. Treated fibers manifested improved interfacial shear strength (IFSS, +8%).

Viscose fibers decorated with silver nanoparticles via an in-situ green route: UV protection, antioxidant activities, antimicrobial properties, and sensing response

AbstractMultifunctional cellulosic fibers are in high demand for use in a variety of applications. Functional cellulosic fibers obtained through green and sustainable approaches are getting special attention because of the need to limit the environmental impact of hazardous chemicals. Herein, a novel facile, efficient, and eco-friendly approach for multifunctional viscose fibers@Ag NPs (VF-Ag) was designed by a rapid, facile, and one-pot biosynthesis green route using guava leaf extract as a reducing and stabilizing agent. UV–Vis, TEM, SEM, EDX, FTIR, and XPS were used to analyze the formation of silver nanoparticles and their subsequent deposition on the surface of viscose fibers. The silver nanoparticles immobilized on the surface of viscose fibers endowed a yellow/brownish color to the fibers as well as improving the dyeing with reactive dye. The VF-Ag samples have multifunctional properties like protective activities against UV radiation and microorganisms, antioxidant activity, and sensor ability toward Hg2+. The results demonstrated that the UPF values of VF-Ag samples ranged from 280 to 355 compared to 103 for VF. The antioxidant activities of VF-Ag ranged from 79 to 85% compared to 9% for VF. VF-Ag samples exhibited excellent antimicrobial activities against Gram-positive and Gram-negative bacteria, very good activities against yeast, and low activities against fungus.VF and VF-Ag were dyed using reactive dye (CI-reactive blue-19) at two color intensities (2.5, and 5%). The results show that the color of VF turned blue, while the color of VF-Ag turned greenish. The color strength of VF-Ag significantly increased with increasing silver content. Furthermore, VF-Ag showed high sensitivity to naked-eye colorimetric sensing for the detection of Hg2+. In straightforward, this innovative approach provides an easy, quick, and low-cost that will open the door for a range of versatile applications for modified viscose fibers in the fields of medical and analytical applications.

Study of Mechanical and Surface Properties of Multi-Walled Carbon Nanotube Grafted Flax Fiber and Its Composites

ABSTRACT The modification method of grafting multi-walled carbon nanotubes (MWCNT, abbreviated as CNT in this paper) on the surface of flax fibers was investigated, i.e. CNT were grafted onto the surface of flax fibers by silane coupling agent under the action of ultrasonic waves to form covalent bonding. The tensile strength of CNT grafted flax fiber is 22% higher than that of untreated flax fiber monofilament. The tensile strength of FFRP composites after CNT grafting treatment increased by 14.2%; however, the tensile modulus of single fiber and composites did not show a significant increase, the interfacial shear strength of the fiber-resin is 38.3% higher than that of untreated filament. The improvement of the contact angle after grafting was investigated by observing the surface morphology, and the surface of flax filament was characterized by scanning electron microscopy and atomic force microscopy. Also the elemental changes of the flax single fiber surface before and after the treatment were analyzed using X-ray photoelectron spectroscopy. The results showed that the tensile strength of flax single fibers, its composites, and interfacial shear strength of fiber-matrix was improved after CNT grafting treatment but the increase of modulus was not obvious.

Hydrothermal enzyme pretreatment on structure and properties of apple branches

Hydrothermal enzyme pretreatment on structure and properties of apple branches

Unlocking the superior flexibility and enhanced catalytic oxidation performance of CoTiO3 nanofibrous membranes through zirconium doping

The development of continuous CoTiO3 (CTO) fibers with prominent catalytic oxidation activity, tunable fibrous structures, and improved recyclability is appealing for application in efficient organic wastewater treatment; however, inescapable flaws remain, such as their inherent brittleness and adverse operability. Herein, a facile and effective strategy is proposed for the fabrication of flexible and mechanically robust CTO nanofibrous membranes through a combination of element doping and sol–gel-assisted electrospinning. Compared with pristine CTO fibers, the resulting zirconium-doped CoTiO3 (ZCTO) nanofibrous membranes displayed remarkably enhanced flexibility and tensile mechanics, which were attributed to their lower crystallinity, smaller grain size, and fewer fiber surface defects. The developed ZCTO fibrous membrane demonstrated exceptional resistance to bending fatigue, retaining a polymer-like bending rigidity of approximately 25 mN even after undergoing 200 reciprocating bending cycles. Furthermore, the incorporation of zirconium into CTO clearly had an advantageous effect on the formation of oxygen vacancies, thereby enhancing the surface adsorption of peroxymonosulfate (PMS), accelerating the electron transfer process, and weakening the peroxy bonds. The tetracycline degradation efficiency of the ZCTO fibers remained at 81.4% within 10 min after 5 continuous cycles. Benefiting from their robust mechanical properties and excellent catalytic activity, the fabricated membranes demonstrated outstanding dynamic catalytic performance under gravity-driven conditions. More importantly, the reported strategy might be adopted and extended to develop a wide range of ceramic fibers with enhanced flexibility and mechanics for catalytic oxidation.

A review of the emerging approaches for developing multi‐scale filler‐reinforced epoxy nanocomposites with enhanced impact performance

AbstractFiber‐reinforced polymer composites (FRPCs) are utilized for myriad applications owing to their exceptional characteristics like high specific strength and stiffness. However, the low‐to‐moderate impact strength of these materials is a major constraint restricting their usage in fields requiring high‐impact performance. To ensure the reliable performance of FRPCs throughout the intended life span, a combination of good static mechanical properties and high impact resistance is crucial. Recent advancements in this field have yielded a breakthrough by developing novel materials that overcome this limitation. This groundbreaking achievement was realized by processing epoxy‐based GFRPs containing a synergistic blend of surface‐modified nano‐clay and compatibilized polymeric fiber micro‐reinforcement. This review provides an overview of advancements in the development of FRPCs, starting from the single‐filler to multi‐scale filler‐reinforced materials. The review elaborates on the effect of reinforcement of various thermoplastic fibers (polyethylene, para‐aramid, and spandex) on the mechanical performance of FRPCs. The necessity of filler compatibilization to enhance interfacial bonding constituents is also discussed. It can be concluded that the choice of surface treatment for a given thermoplastic fiber is governed by its chemical composition, the functional groups to be added on its surface through a specific compatibilization treatment, and the chemical nature of other constituents of the composite system with which the treated fiber surface interacts. Further, the greater the elasticity and ductility of the reinforced thermoplastic fiber, the higher the impact strength of the resulting epoxy‐based GFRPs. Finally, the review brings forth the potential opportunities for future research in this area.Highlights Discussed recent advancements in epoxy‐based GFRPs with multi‐scale filler reinforcement. Multi‐scale filler‐reinforced epoxy‐based GFRPs have myriad applications in aviation, automobile, marine, sports, etc. Nano‐/micro‐fillers in their pristine state degrade the mechanical performance of epoxy‐based GFRPs. Filler compatibilization is essential for achieving superior mechanical performance in epoxy‐based GFRPs. Reinforcing compatibilized soft/ductile thermoplastic fibers resulted in a notable increase in impact strength while maintaining tensile properties.

Thermal aging behavior and heat resistance mechanism of ultraviolet crosslinked ultra‐high molecular weight polyethylene fiber

AbstractAs advances in heat resistant ultrahigh molecular weight polyethylene (UHMWPE) fiber via ultraviolet (UV) crosslinking, it is worth paying attention to its thermal aging behavior and heat resistance mechanism. UHMWPE fibers in different forms, the fully drawn yarn (FDY) and the UV crosslinked FDY (UVFDY), are subjected to isothermal aging at 135°C. The effects of thermal aging on their surface morphology and mechanical properties are studied and compared initially. The results demonstrate that UVFDY is a kind of a heat‐resistant fiber. Subsequently, to reveal the heat resistance mechanism of UVFDY, its crystalline and orientation structure evolution during thermal aging are further studied. It is indicated that the formation of dense‐packing crystals and disorientation behavior lead to fiber shrink, so that a number of grooves appear on the fiber surface. Since the crosslinked stucture of UVFDY hinders its molecules movement, the crystallization and disorientation behavior of UVFDY are weaker than those of FDY, resulting in UVFDY possesses slighter thermal shrinkage (Ts), fewer grooves and better mechanical properties than those of FDY. Therefore, the heat resistance of the fiber improves effectively after UV crosslinking. This work provides insights into the structure–property relationship of UVFDY during thermal aging, and offers basis data for its application in specific conditions.

Multiscale enhancement of carbon/carbon composite performance by self-assembly of sulfonated graphene with silane-treated carbon fibers

The application prospects of carbon/carbon composites are greatly limited by interfacial cracks and pores caused by binder pitch displacement and cracking during high-temperature carbonization. In this study, silane coupling agent was coated on the surface of oxygen plasma-treated carbon fibers (CFs) and subsequently electrostatically self-assembled with sulfonated graphene (SG) to improve the interfacial bonding between filler and CTP. The results indicate that the tensile strength of carbon fiber treated with silane coupling agent increased by 19 % compared to untreated CF. This increase in strength may be related to the layer of silane coupling agent that repaired the grooves and imperfections on the CF surface. The addition of SG not only improves the distribution characteristics of the fibers, allowing the silane-treated CF to play a greater role in the matrix, but also creates a three-dimensional hydrogen-bonded cross-linking between the SG and the coal tar pitch (CTP) on the surface of the fibers. This inhibits CTP displacement and pyrolysis, achieving a tight bonding of the fiber to the matrix. The composites' structural integrity and mechanical properties were significantly improved due to the synergistic effect of silane-treated CF and SG. The compressive strength was 216.98 MPa, with a flexural strength of 54.78 MPa, 250 % higher than the untreated carbon fiber-reinforced composites. Additionally, the porosity decreased by 31.5 %, and the antioxidant properties increased. The study presents a potential solution to improve the performance of carbon/carbon composites by using the silane-treated CF-SG multiscale reinforced phase.

Enhanced Removal of Viral Aerosols using Nanosilver/TiO2-Chitosan Filters Combined with a Negative Air Ionizer

The presence of airborne viruses in bioaerosols is a significant and ongoing public health concern. In this context, this study aimed to develop a new filter that integrates nanosilver into a TiO2-chitosan matrix (nano-Ag/TiO2-CS) to inactivate the non-enveloped bacteriophage MS2 as a viral aerosol surrogate. The materials were characterized using various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). The SEM images showed that the nano-Ag particles were spheres with a high surface area for virus interactions and that the fiber surfaces were covered by nano-Ag, which enhanced contact with viruses. The optimal 5wt% nano-Ag/TiO2-CS filter combined with a negative air ionizer (NAI) showed the highest viral aerosol removal efficiency, which reached 97%. The use of an NAI during filtration enhanced the inactivation of the viral aerosols. A long-term antiviral efficacy assessment showed that the nano-Ag/TiO2-CS filter demonstrated robust durability, which is vital for real-world applications. The nanofilter proposed in this work is simple, safe, and cost-effective for inactivating viral aerosols to improve indoor air quality.

Enhancing the attraction of positively charged precursors of conductive polymer poly(3,4-ethylenedioxythiophene) by anchoring sulfonate groups in cellulose fibres

Interfacial interactions are key to the development of high-performance coatings such as conductive polymer layers on fibrous materials. In this work, we present an approach of strengthening the interaction by forming ionic bonds between cellulose fibres and the conductive polymer layer by introducing a sulfonate group on cellulose fibres. The ionic bonds are formed between anchored sulfonate group and the positively charged precursor 3,4-ethylenedioxythiophene (EDOT), followed by the deposition and polymerisation of poly(3,4-ethylenedioxythiophene):sulfate (PEDOT:SO4) on the fibrous substrate surface. The conductance of the PEDOT:SO4 coated substrate with anchored sulfonate groups coated may be 1.7 times higher compared to the conductance of the unmodified cellulose substrate depending on experimental conditions. EDX measurements confirm the presence of sulfur and a shift of zeta potential at lower pH supports the evidence of the anionic anchored groups on the fibre surface. Our study therefore provides a new way to enhance the affinity of fibrous cellulose materials towards polymer conductive coatings.

Concealed fluorescent anti-counterfeiting paper prepared by loading perovskite and lead-metal-organic framework on cellulose fibers

Counterfeiting has caused great concern all over the world. What's more, the fluorescent materials play an important role in technological research and development for high-security. In this work, lead-metal-organic framework (Pb-MOF) and perovskite (MAPbBr3) were used in papers to achieving fluorescence counterfeiting. Pb-MOF, as the template or precursor of MAPbBr3, were in-situ generated on the surface of cellulose fibers (CFs) to preparing into hand sheets (Pb-MOF@CFs). Through the analysis of experimental results, it was found that ligands, reaction systems, addition sequences of drugs, time, etc. would affect the deposition of Pb-MOF on the surface of CFs. Using CH3NH3Br (MABr) as the anti-counterfeiting ink to write on Pb-MOF@CFs, the orange writing leaped across the paper, which caused by Pb in Pb-MOF chemically reacting with MABr forming MAPbBr3. The orange writing displayed green fluorescence under 365 nm ultraviolet lamp excitation. The orange writing with green fluorescence could be extinguished and reconstructed, which had promise for reuse. In addition, fluorescent security papers (MAPbBr3@Pb-MOFs@CFs) were prepared by immersing Pb-MOF@CFs in MABr solution. The fluorescence of MAPbBr3@Pb-MOFs@CFs opened when the surface of it was scraped under 365 nm ultraviolet lamp. This unique fluorescence property was very important in improving the security of products. Consequently, the ongoing research on perovskite and MOFs materials is of great significance.

Regulation of fiber surface nucleation kinetics via ordered nitrogen-rich carbon dots

Three dimensional (3D) carbon-based current collectors have attracted much attentions as host for Li metal anodes (LMAs) owing to their lightweight, flexible, and wide sources etc. However, the lithiophobic nature of carbon makes it difficult to achieve low nucleation overpotential and dendrite-free Li deposition. Herein, carbon dots (CDs) with nitrogen (N)-rich were introduced to modify carbonized cotton fiber (CCF) coated by reduced graphene oxide (CD@RGCCF). Coating graphene oxide (GO) increases the active site of cotton fiber (CF), which facilitates the growth of CDs on the surface of CF fiber. The introduction of ordered structure CDs drives fast migration of Li+ in the “highway-like” channels and induces the uniform nucleation of Li in the initial stage. As a result, the obtained CD@RGCCF decreases the nucleation overpotential of Li, and achieves dendrite-free Li deposition. the CD@RGCCF|Li half cells exhibit extending cycling life over 5000 h with a voltage hysteresis of 10.5 mV at 2 mA cm−2. As coupled with the LiFePO4 (LFP), the Li@CD@RGCCF||LFP composite anode enables a high reversible specific capacity and improved cycle stability. This work provides a low-cost modification method for carbon substrate to realize dendritic-free LMAs.

The fabrication of Ni@Luffa nanocomposite as green catalyst for water pollutants Thymus vulgaris-assisted growth of nickel nanoparticles onto Luffa fibers: A robust and recyclable catalyst for the reduction of organic pollutants

A green and efficient synthetic pathway was developed to prepare nickel@Luffa nanocomposite. Thymus vulgaris extract was used to functionalize the surface of Luffa fibers with hydroxyl, carbonyl, and amide groups, which assisted in the adsorption of nickel ions. The scanning electron microscope images revealed that nickel nanoparticles grew as aggregates of semi-spherical particles and randomly dispersed on the Luffa fibers. The X-ray diffraction pattern of the nickel@Luffa nanocomposite showed the diffraction pattern of a face-centered cubic Ni crystal. XPS spectrum indicated the formation of metallic Ni at the Luffa surface. The prepared nickel@Luffa was used to catalyze the degradation of 4-nitrophenol, methyl orange, bromophenol blue and a mixture of both. The reaction rate constant for nickel@Luffa nanocomposite was calculated as 15.47×10-3 sec-1 at pH=10 and even after ten cycles its conversion was about 90%. The nickel nanoparticles could be recycled/ reused for ten catalytic cycles with adequate catalytic activity. Such synthetic pathways encourage the application of renewable natural resources to fabricate separable/recyclable heterogeneous catalyst for many important reactions. The proposed nanocomposite is industrially applicable and environmentally-benign, fulfilling the requirements for the sustainable development.

Enhanced Copper Ion Adsorption by Rice Husk and Sugarcane Bagasse-based Magnetic Nanoparticles Biocomposites

Rice husk and sugarcane bagasse are biomass waste by-products of agriculture activities. High cellulose content makes them a potential material to develop. Biomass utilization is more interesting to develop due to its high cellulose content and nature abundance. Cellulose from rice husk and sugarcane bagasse is utilized as fiber in producing magnetic biocomposites. The Biocomposites can adsorb Cu(II) ions in aqueous solutions. A one-step solvothermal reaction was used to synthesize biocomposites. The amine functionalization on biocomposites was also studied for adsorption performance. The magnetic particle was generated on the surface of fiber and verified by XRD as Fe3O4. Amine group on biocomposites is also found on 570 cm-1 and 1636 cm−1 peaks for Fe-O bonds and N-H bending, respectively. Batch isothermal adsorption employing magnetic biocomposites has optimal conditions for Cu(II) ions adsorption at pH 5 for 60 minutes, with an adsorption capacity of 118.26 mg/g. The reusability of biocomposites for the next run showed a good performance at 3rd repetitions with only a decrease in adsorption capacity of 8.81%. The rice husk and sugarcane bagasse-based magnetic nanoparticles biocomposites can adsorb Cu(II) ions and potential material to develop for wastewater treatment.