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Influence of Non-Toxic Magnetic Cellulose Nanofibers on Chitosan based Edible Nanocoating: A Candidate for Improved Mechanical, Thermal, Optical, and Texture Properties
摘要： The present work demonstrates the formulation of cellulose nanofiber (CNF) or magnetic cellulose nanofiber (mgCNF) dispersed chitosan based edible nanocoating with superior mechanical, thermal, optical and texture properties. The fabrication of mgCNF is successfully achieved through single-step co-precipitation route, where iron particles get adsorbed onto CNF. The thermal stability of mgCNF is improved considerably, where ~17% reduction in weight is observed, whereas CNF degrades completely under identical conditions. TGA analysis shows that there is an improvement in thermal stability for both CNF and mgCNF reinforced CS nanocoatings, where mgCNF provides more heat dimensional stability than CNF dispersed CS nanocoatings. Further, the edible nanocoatings are stable even at the temperature of heat treatment such as food sterilization. The mechanical property of the mgCNF dispersed chitosan (CS) shows remarkable improvement in tensile strength (57.86±14 MPa) and Young’s modulus (2348.52±276 MPa) compared to neat CS (6.27±0.7 MPa and 462.36±64 MPa, respectively). To recognize the developed materials as safe as food, the quantification of iron is made by using ICP-MS technique. It is noteworthy to mention that mgCNF coated CS help in improving the texture of cut pineapples in comparison with uncoated pineapple slices at ambient condition.
关键词： chitosan,magnetic cellulose nanofibers,cellulose nanofiber,edible nanocoating,packaging property
更新于2025-11-21 11:01:37
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Ups and Downs of Water Photodecolorization by Nanocomposite Polymer Nanofibers
摘要： Given the exponentially expanding water pollution causing water scarcity, there is an urgent need for operative nanotechnological systems that can purify water, with insignificant energy consumption, and rapidly. Here, we introduce a nanocomposite system based on TiO2 nanoparticles (NPs) and PES nanofibers (NFs) that can adsorb and then photodecompose organic water pollutants such as dye molecules. We evaluate pros and cons of this system with respect to its purification efficiency and structural properties that can be impacted by the photocatalytic activity of the nanofillers. While the material is superhydrophilic and able to remove 95% methylene blue (MB) from water via adsorption/photodecomposition, its thermomechanical properties decline upon UV irradiation. However, these properties still remain at the level of the neat NFs. The removal behavior is modeled by the first- and second-order kinetic models from the kinetic point of view. The nanocomposite NFs’ removal behavior complies much better with the second-order kinetic model. Overall, such feedbacks implied that the nanocomposite can be effectively applied for water treatment and the structural properties are still as reliable as those of the neat counterpart.
关键词： nanofiber,photodegradation,dye removal,water treatment,photocatalysis
更新于2025-11-14 17:03:37
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Block copolymer brush layer-templated gold nanoparticles on nanofibers for surface-enhanced Raman scattering optophysiology
摘要： A nanothin block copolymer (BCP) brush-layer film adsorbed on glass nanofibers is shown to address the long-standing challenge of forming a template for the deposition of dense and well dispersed nanoparticles on highly curved surfaces, allowing the development of an improved nanosensor for neurotransmitters. We employed a polystyrene-block-poly(4-vinylpyridine) BCP and plasmonic gold nanoparticles (AuNPs) of 52 nm in diameter for the fabrication of the nanosensor on pulled fibers with diameters down to 200 nm. The method is simple, using only solution processes and a plasma cleaning step. The templating of the AuNPs on the nanofiber surprisingly gave rise to more than one order of magnitude improvement in the surface-enhanced Raman scattering (SERS) performance for 4-mercaptobenzoic acid compared to the same AuNPs aggregated on identical fibers without the use of a template. We hypothesize that a wavelength-scale lens formed by the nanofiber contributes to enhancing the SERS performance, to the extent that it can melt the glass nanofiber under moderate laser power. We then show the capability of this nanosensor to detect the co-release of the neurotransmitters dopamine and glutamate from living mouse brain dopaminergic neurons with a sensitivity one order of magnitude greater than with aggregated AuNPs. The simplicity of fabrication and the far superior performance of the BCP-templated nanofiber demonstrates the potential of this method to efficiently pattern nanoparticles on highly curved surfaces and its application as molecular nanosensors for cell physiology.
关键词： block copolymer brush,neurosciences,SERS optophysiology,nanofiber,neurotransmitters
更新于2025-09-23 15:23:52
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Low-cost effective photocatalytic activity under visible light of pitch-based porous carbon nanofiber composites aided by zinc oxide
摘要： To explore and develop an economical, novel, and effective photocatalyst for the degradation of methylene blue (MB) under visible-light irradiation, polyacrylonitrile (PAN)/pitch-based carbon nanofibers (CNFs) with ZnO (PPZn) are successfully produced by one-step electrospinning of PAN, pitch, and zinc acetate in dimethylformamide (DMF) solution. The charge separation rate, adsorption capacity, and visible-light harvesting effects are all enhanced by the synergistic effect of PAN/pitch-based CNFs and ZnO coupling. The resulting PPZn photocatalysts exhibit excellent removal capacity of 100% of MB within 30 min and a kinetic rate constant of 0.018 min?1 under visible light. PPZn also exhibits a consistent and stable photocatalytic performance by maintaining nearly 100% removal of 15 ppm MB over 8 regeneration cycles. The PP-based CNFs in PPZn act as a charge reservoir to afford fast transport for suppressing the e?–h? recombination and high electrical conductivity induced by the pitch, thereby expanding the visible-light response. The PP(3)Zn composites demonstrate a promising potential as a low-cost photocatalyst material offering excellent photocatalytic efficiency in the visible-light spectrum.
关键词： Carbon nanofiber,ZnO,Methylene blue,Pitch,Visible light,Photocatalytic activity
更新于2025-09-23 15:23:52
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Colorimetric and turn-on Fluorescence Chemosensor for Hg2+ Ion Detection in Aqueous Media
摘要： A new rhodamine 6G based fluorescent and colorimetric chemosensor, containing N-methyl imidazole nucleus, for the selective detection of Hg2+ ion was designed and synthesized. The results of UV-Vis and fluorescence spectral study indicated that the receptor is selective and sensitive towards Hg2+ with no noticeable interference with other competitive metal ions. The addition of Hg2+ to the receptor induced a rapid color change to pink from colorless and the turn-on fluorescence response toward Hg2+ among different cations was studied. The stoichiometric ratio of 1:1 between the receptor and Hg2+ was supported by Job’s plot. The color change and turn-on fluorescence response upon addition of Hg2+ ion was ascribed by the spirolactam ring-opening mechanism. The probable mode of binding between the receptor and Hg2+ was confirmed by 1H NMR and Mass spectral study. For the practical application, its electrospun nanofiber test strips successfully applied to recognize Hg2+ ion in aqueous media.
关键词： Sensing,Mercury ion,Nanofiber,Fluorescent
更新于2025-09-23 15:23:52
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Modulating Electrical Performances of In <sub/>2</sub> O <sub/>3</sub> Nanofiber Channel Thin Film Transistors via Sr Doping
摘要： Although In2O3 nanofibers (NFs) are considered as one of the fundamental building blocks for future electronics, the further development of these NFs devices is still seriously hindered by the large leakage current, low on/off current ratio (Ion/Ioff), and large negative threshold voltage (VTH) due to the excess carriers existed in the NFs. A simple one-step electrospinning process is employed here to effectively control the carrier concentration of In2O3 NFs by selectively doping strontium (Sr) element to improve their electrical device performance. The optimal devices (3.6 mol% Sr doping concentration) can yield the high field-effect mobility (μfe ≈ 3.67 cm2 V?1 s?1), superior Ion/Ioff ratio (≈108), and operation in the energy-efficient enhancement-mode. High-κ Al2O3 thin films can also be employed as the gate dielectric to give the gate voltage greatly reduced by 10× (from 40 to 4 V) and the μfe substantially increased by 4.8× (to 17.2 cm2 V?1 s?1). The electrospun E-mode Sr-In2O3 NF field-effect transistors (NFFETs) can as well be integrated into full swing of inverters with excellent performances, further elucidating the significant advance of this electrospinning technique toward practical applications for future low-cost, energy-efficient, large-scale, and high-performance electronics.
关键词： enhancement mode,Sr element,high performance,In2O3 nanofiber,inverter
更新于2025-09-23 15:23:52
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Fabrication of PAN/ZnO Nanofibers by Electrospinning as Piezoelectric Nanogenerator
摘要： Piezoelectric nanogenerator is a material that is used for converting mechanical energy to electrical energy. This research aimed to study the piezoelectric nanogenerator properties in PAN/ZnO nanofibers layered on the stainless-steel substrate. ZnO nanoparticles that were used in this work were synthesized by coprecipitation method. The ZnO nanoparticles were mixed with PAN dissolved with DMF. Fabrication of PAN-ZnO nanofibers was done using the electrospinning method on the stainless-steel substrate. The formed PAN/ZnO nanofibers were then characterized using XRD, SEM, and FTIR. To test the piezoelectric nanogenerator properties, PAN/ZnO nanofibers were combined to PAN nanofibers and coated on the stainless-steel substrate to form piezoelectric nanogenerator device. This device was then connected to an electrometer and an oscilloscope to measure the current and voltage resulted after bending. The results of XRD of ZnO nanoparticles had the wurtzite crystal structure with the size of about 46 nm. Meanwhile, the PAN/ZnO had an amorphous structure. The test results of piezoelectric nanogenerator properties showed the value of voltage and current of 7.22 V and 47.48 μA, respectively. PAN/ZnO nanofibers on the stainless-steel substrate are potential to be the material of piezoelectric nanogenerators in general.
关键词： electrospinning,PAN/ZnO nanofiber,energy harvesting,piezoelectric nanogenerator
更新于2025-09-23 15:23:52
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Effects of Calcination Temperature on Morphology and Structure of CeO2 Nanofibers and their Photocatalytic Activity
摘要： Calcination temperature plays a critical role on morphology and structure of CeO2 nanofibers, thus affecting its photocatalytic activity. CeO2 nanofibers with diameter of 95 nm were successfully fabricated by electrospinning combining with calcination. The calcination temperature was determined by TGA results ranging from 500℃ to 800℃. The morphology and structure of samples obtained with different calcination temperatures, have been characterized by SEM and XRD. Meanwhile, the specific surface area of samples were checked by BET, that was decreased 17 times from 56.3 m2/g to 3.3 m2/g, as the temperature increasing from 500℃ to 800℃. Normally, the higher specific surface area, the more efficiency photocatalytic activity. But it was interesting that the photodegradation rate of methylene blue was increased from 67% to 98% for CeO2 catalyst obtained at 500℃ and 800℃, with 4 times higher kinetic constant reaction rate under UV irradiation for 60 min. It demonstrates that the photocatalytic activity of CeO2 nanofibers catalyst is not directly related to the specific surface area, and increasing the calcination temperature has a positive effect for the photocatalytic efficiency.
关键词： Calcination,Porous Materials,Microstructure,CeO2 Nanofiber,Photocatalysis
更新于2025-09-23 15:23:52
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Synthesis and characterization of nanofiber-type hydrophobic organic materials as electrodes for improved performance of PVDF-based piezoelectric nanogenerators
摘要： Poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives are synthesized by oxidative polymerization using sodium dodecyl sulfate (SDS) as an anionic surfactant dopant. The resulting polymeric materials featuring nanofiber-type one-dimensional (1D) structures are identified as poly(2-butyl-2,3-dihydrothieno[3,4-b][1,4]dioxine:dodecyl sulfate (PEDOT-C4:DS) and poly(2-hexyl-2,3-dihydrothieno[3,4-b][1,4]dioxine:dodecyl sulfate (PEDOT-C6:DS). The ratio of the DS anion doped into PEDOT-C4:DS and PEDOT-C6:DS is 0.16 and 0.23, respectively. The contact angle of water on the PEDOT-C4:DS and PEDOT-C6:DS films is 76.6° and 87.7°, respectively, showing hydrophobic properties similar to that with water on PVDF. It facilitated the fully uniform film formation due to excellent surface matching. Peeling force of PEDOT-C4:DS and PEDOT-C6:DS is stronger than the one of PEDOT:PSS-CNT composite. GIWAX analysis showed that PEDOT-C4:DS formed the highly ordered edge-on structure and PEDOT-C6:DS formed the bimodal orientation consisting of edge-on structure mainly and face-on structure slightly. The electrical conductivity (σPEDOT-C4:DS=50.0 S cm-1) of PEDOT-C4:DS is 41.7 times higher than that of PEDOT:PSS (σPEDOT:PSS=1.2 S cm-1). The output signals (maximum voltages/currents) of piezoelectric nanogenerators (PNGs, electrode/PVDF/electrode) using these materials as electrodes are PNG-1 (PEDOT:PSS-CNT composite) 1.25 V/128.5 nA, PNG-2 (PEDOT-C4:DS) 1.54 V/166.0 nA, and PNG-3 (PEDOT-C6:DS) 1.49 V/159.0 nA. Of these, PNG-2 & PNG-3 show maximum piezoelectric output power of 63.0 nW and 59.9 nW at 9 MΩ compared to PNG-1 (41.0 nW at 10 MΩ). They are enhanced up to 53.7%. The excellent surface matching between a piezoelectric active material and an electrode material leads to high output power.
关键词： 4-ethylenedioxythiophene) derivative,poly(3,nanofibrillar network,piezoelectric nanogenerator,nanofiber,hydrophobicity
更新于2025-09-23 15:23:52
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Cowpea-structured PVDF/ZnO Nanofibers Based Flexible Self-powered Piezoelectric Bending Motion Sensor Towards Remote Control of Gestures
摘要： Interactive human-machine interface (iHMI) is a bridge connecting human beings and robots, which has an important requirement for perceiving the change of pressure and bending angle. Here, we designed a flexible self-powered piezoelectric sensor (PES) based on the cowpea-structured PVDF/ZnO nanofibers (CPZNs) for remote control of gestures in human-machine interactive system. Due to the synergistic piezoelectric effect of hybrid PVDF/ZnO and the flexibility of polymer, this PES exhibited excellent bending sensitivity of 4.4 mV deg-1 ranging widely from 44 ° to 122 °, fast response time of 76 ms, and good mechanical stability. Besides, the PES could operate under both bending and pressing mode, show ultrahigh pressing sensitivity of 0.33 V kPa-1, with response time of 16 ms. When integrated in iHMI, the PES could be conformably covered on different curve surfaces, demonstrated accurate bending angle recording and fast recognition for realizing intelligent human-machine interaction. On this basis, the application of remote control of robotic hand was successfully realized in form of acting the same gesture as human hand synchronously. This CPZNs-based self-powered PES is distinct and unique in its structure and fundamental mechanism, and exhibits a prospective potential application in iHMI.
关键词： human-machine interaction,cowpea-structured nanofiber,bending monitoring,self-powered,PVDF/ZnO
更新于2025-09-23 15:21:01