Nanofiber Composite Films Research Articles

Drying-Induced Surface Wrinkles Generated on Chitosan Films Having Polyion Complex Skin Layers: Effects of Physical Properties of Skin Layers and Substrates on Surface Wrinkling upon Drying

Abstract The effects of the physical properties of skin layers and substrates on drying-induced surface wrinkling are investigated with a system using chitosan films having polyion complex (PIC) skin layers. The PIC layers are fabricated with diverse anionic polymers having similar molecular weights on a chitosan (CS) film surface, and the films are dried. In all cases, surface wrinkles form but their sizes vary widely depending on the molecular structure. In particular, wrinkles formed with ligninsulfonate are much larger than those formed with the others. The skin layers differ significantly in surface hardness but not in thickness, indicating that wrinkle sizes induced by PIC skin layers are predominately determined by the hardness of the layers or by physical properties affected by hardness, such as shrinkage volume. The effects of the elastic moduli and shrinkage volume of the substrates are evaluated with higher molecular weight CS and surface-deacetylated chitin nanofiber composite CS films that have different elastic moduli but show very similar swelling–drying behaviors. The wrinkle sizes and skin layer thicknesses also suggest that wrinkle size in this system depends on the hardness of the skin layers or on the physical properties affecting the hardness.

Fluorescent markable multi-mode pressure sensors achieved by sandwich-structured electrospun P(VDF-HFP) nanocomposite films

The development of multi-functional piezoelectric polymer film is of great significance to many application fields, such as those involving wearable functional devices, flexible sensors, and actuators. In this study, multilayer P(VDF-HFP) nanocomposite films were prepared using electrospinning technology with the MWCNTs-COOH and Eu complexes as fillers to achieve a fluorescent labeled multimode pressure sensor. The sandwich-structured devices were prepared using both electrospun polyurethane (PU) nanofiber films and P(VDF-HFP) composite nanofiber films, where the P(VDF-HFP) composite nanofiber film was used as the core electroactive layer and the PU nanofiber film was used for the skin layers. The resulting sandwich-structured devices showed high sensitivity at ultra-low-pressure (<1 kPa), high piezoelectric output (2.1V), fluorescence functionality, excellent flexibility, and good thermal properties. Our results suggest that sandwich-structured devices based on fluorescent labeled electroactive P(VDF-HFP) composite nanofiber films have great potential for application in the fields of multi-functional flexible sensors and intelligent wearables. • Fluorescent markable multi-mode flexible pressure sensors were fabricated. • Synergistic effect of MWCNTs-COOH and Eu complexes greatly improves the piezoelectric outputs. • The sensors with high electric outputs exhibit high pressure sensitivity at ultra-low-pressure. • The nanocomposites can be applied as multifunctional flexible sensors and intelligent wearables.

Ultrathin flexible electrospun carbon nanofibers reinforced graphene microgasbags films with three-dimensional conductive network toward synergetic enhanced electromagnetic interference shielding

In recent years, graphene-based composite films have been greatly developed in the field of electromagnetic shielding interference (EMI). However, it is still a huge challenge to prepare graphene-based composite films with excellent mechanical properties, conductivity and electromagnetic shielding properties. In this work, we adopted a facile and effective method by annealing the alkali-treated polyacrylonitrile (aPAN) nanofibers reinforced graphene oxide (GO) composite films at 2000 °C to obtain graphene-carbon nanofibers composite films (GCFs). Microscopically, carbon nanofibers (CNFs) were intercalated into the graphene sheets, and microgasbags structure was formed during the heat treatment process. The special structure makes GCFs have superior tensile strength (10.4 MPa) at 5% strain. After repeated folding over 1000 times, the films still demonstrate excellent structural integrity and flexibility performance. Interestingly, the graphene-based composite films with 10 wt% aPAN nanofibers exhibit an extremely low density of about 0.678 g/cm3 and excellent electrical conductivity of 1.72 × 105 S/m. Further, an outstanding electromagnetic shielding effectiveness (SE) of 55–57 dB was achieved, and the corresponding value of the specific SE/thickness can reach 67,601–70,059 dB·cm2/g, which is the highest among reported graphene-based shielding materials. The significant electromagnetic shielding performance is due to the synergistic enhancement effect brought by the excellent conductivity of carbon nanofibers and graphene, the formed effective conductive network and the microgasbags structure. Electromagnetism simulation further clarified that the underlying mechanism should be mainly attributed to the conduction loss and multiple reflections caused by the special structure of GCFs. This work will provide new solutions for low density, high flexibility and excellent electromagnetic shielding properties materials in the next generation of foldable and wearable electronics.

Enhancing anti-E. coli O157:H7 activity of composite phage nanofiber film by D-phenylalanine for food packaging

Escherichia coli O157:H7 (E. coli O157) is still one of the main pathogenic strains causing food poisoning. Here in, we established a strategy that can simultaneously remove free E. coli O157 and the biofilms it forms. Composite nanofiber (fP-NF) films were synthesized successfully by co-encapsulating E. coli O157 phages which isolated from domestic sewage and D-phenylalanine (D-Phe) into sodium alginate (SA)/polyethylene oxide (PEO) nanofibers by electrospinning. And dehydrated trehalose was added as a phage protectant. When SA:PEO is 3:9, the spinning solution has the optimum conductivity and viscosity, the average diameter of the obtained fP-NFs is 421.87 nm, and the mechanical strength and transparency of the fP-NF film are the best. The thermal stability of the fP-NF film was good, and the phage activity in the fiber was well preserved. The remaining population of phages in fP-NF membranes was still close to 106 PFU/mL after one week of placement, and the cumulative release efficiencies of phages at both room temperature (25 °C) and refrigerated storage temperature (4 °C) were above 70%. The antibacterial experiment showed that compared with the control group, the addition of D-Phe slightly enhanced the antibacterial activity of the nanofiber films against free E. coli O157, and the bactericidal rate within 8 h was 99.74%. On the other hand, D-Phe significantly enhanced the inhibitory activity of the nanofiber films against E. coli O157 biofilms, with the inhibition rate exceeding 99.99% within 72 h. The application results further confirmed that the addition of D-Phe could significantly enhance the inhibitory activity of nanofiber films on E. coli O157 proliferation and biofilm formation during short-term storage of beef and fruits and vegetables. It provides an important strategy and reference for the development of new active food packaging materials.

Maximizing ion storage in MXene/Kevlar nanofiber composite films for enhanced capacitive energy storage

MXene is a promising two-dimensional (2D) metal carbides and nitrides materials for energy storage devices, due to its efficient, low-cost and eco-friendly synthesis technology. MXene possesses high mechanical strength, metallic conductivity, and excellent capacitance performance. However, traditional electrode films obtained from 2D nanomaterials suffer from restacking issue, which hinders the transmission of ion and results in slow ion transport dynamics between layers. The improvement of ion transfer rate of MXene electrode materials is a hot spot in the current research of 2D nanomaterials. Herein, we fabricated the Ti3C2Tx MXene/aramid nanofiber (ANF) composite film with high specific surface area via a freezing method. The obtained MXene/ANF composite film presents high specific capacitance (174.3 F g−1 at a current density of 0.05 A g−1), excellent rate performance and high cycling stability (∼84.4% capacity retention after 10 000 cycles). The improvement of electrochemical performance is attributed to the smaller size of 2D sheets that effectively shorten ion diffusion path. Thus, both the diffusion rate and storage ability of electrolyte ions increase in the interstitial space between 2D sheets. In addition, ANF obtained from the commercial Kevlar yarns interacted with 2D sheets to enhance the mechanical strength of the composite films. Thus, the self-supporting MXene/ANF composite film with high specific surface area can be used as an electrode material of supercapacitors to present high specific capacitance and excellent cycling stability. This work provides a simple and effective way to construct high specific surface area 2D materials that present huge potential in energy storage fields.

The role of Ag NPs in PVA electrospun NFs for ultra-high sensitivity photodetector

This work aimed to produce PVA and PVA/Ag nanofibers ultra-high sensitivity photodetector by electrospinning. The electrospinning process was used to successfully prepare PVA nanofibers and a PVA-Ag nanofiber composite. FE-SEM, XRD, UV, I-V characterizations are used to study the morphological, structural, optical, and electrical properties of the material. In contrast, the PVA-Ag nanofiber composite film displayed a cubic structure with favored orientation (200) that indicated the presence of Ag NPs in the PVA-Ag nanofibers film. While the optical energy gap for PVA was 3.96 eV, it was only 2.14 eV for PVA-Ag nanofibers composite film, making this composite sensitive to visible light, particularly green light at 550 nm with a 65% photosensitivity. The optical energy gap of PVA-Ag nanofibers composite was used to tailor this film from the ultraviolet to the visible spectrum.

All-Nanofiber Network Structure for Ultrasensitive Piezoresistive Pressure Sensors.

Sensing materials with fiber structures are excellent candidates for the fabrication of flexible pressure sensors due to their large specific surface area and abundant contact points. Here, an ultrathin, flexible piezoresistive pressure sensor that consists of a multilayer nanofiber network structure prepared via a simple electrospinning technique is reported. The ultrathin sensitive layer is composite nanofiber films composed of poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) and polyamide 6 (PEDOT:PSS/PA6) prepared by simultaneous electrospinning. PEDOT:PSS conductive fibers and PA6 elastic fibers are interwoven to form a multilayer network structure that can achieve ultrahigh sensitivity by forming a wealth of contact points during loading. In particular, gold-deposited PA6 fibers as upper and lower flexible electrodes can effectively increase the initial resistance. Due to this special fiber electrode structure, the sensor is able to generate a large electrical signal variability when subjected to a weak external force. The devices with different sensing properties can be obtained by controlling the electrospinning time. The sensor based on the PEDOT:PSS/PA6 nanofiber network has high sensitivity (6554.6 kPa-1 at 0-1.4 kPa), fast response time (53 ms), and wide detection range (0-60 kPa). Significantly, the device maintains ultrahigh sensitivity when cyclically loaded over 10,000 cycles at 5 kPa, which makes it have great prospects for applications in human health monitoring and motion monitoring.

Broad-wave reflection of doping double-layered nanofibers in polymer-stabilized cholesterol-based liquid crystal films

In this study, polymer-stabilized cholesterol-based liquid crystal (PSCLC) films with broadband reflection were prepared using bilayer sodium alginate (SA)/polyvinyl alcohol (PVA) composite nanofiber films as a carrier for loaded photoinitiators as well as chiral compounds. The loaded photoinitiators and chiral compounds in the bilayer nanofibers could load a superposition of pitch inhomogeneous distribution to achieve broadband reflection. The effects of the concentration of chiral compounds in the films, the concentration of polymerization monomers, polymerization time, light intensity and temperature on the wave width were investigated. The morphology and diameter of the nanofibers were observed by SEM, and the weaving of the liquid crystals (LCs) was characterized by POM. The reflectance wavelengths were mainly measured by a UV–Vis spectrophotometer. This method broadens the wavelength of cholesteric phase liquid crystals from 256 nm to 436 nm, and lays the foundation for the study of the combination of wide wave reflection through nanofiber films.

Fabrication of chitosan/PVP/dihydroquercetin nanocomposite film for in vitro and in vivo evaluation of wound healing

The high cost of wound healing treatment, the slow recovery of wounds, and the uncertainty of being affected by the body's physiological activities constitute a serious burden on public health. In this work, we report the preparation and characterization of chitosan (CS), PVP, and dihydroquercetin (DHQ) nanofiber film used as wound excipients, as well as in vivo and in vitro evaluations, and verify that the film is effective in wounds. The results show that the prepared film has good morphology, thermal stability and hydrophilicity. In vitro studies have shown that it has antibacterial activity against S.aureus and E.coli, and the DPPH free radical scavenging rate proves that the fiber film has antioxidant activity. MTT cytotoxicity test proved that the film is non-toxic to Hacat cells. Animal experiments have proved that wounds treated with CS-PVP-DHQ nanofiber film heal faster. This article also studied the composite nanofiber film by inducing autophagy pathway and increasing the expression of pan-keratin, vascular endothelial growth factor VEGF and CD31 to promote wound healing. Therefore, the nanofiber film herein show great potential in wound healing applications.

A peanut-shaped optical fiber sensor coated with electrospinning polyvinyl alcohol/nano-ZnO film

A peanut-shaped optical fiber sensor cascaded with a fiber Bragg grating (FBG) was designed to measure temperature and humidity. A mixed polyvinyl alcohol/nano-zinc oxide (PVA/nano-ZnO) solution was electrospinning into nanofibers, and these nanofibers were then attached to the peanut-shaped structure surface to form a nanofiber film. Humidity changes caused changes in both the refractive index and the thickness of the PVA/nano-ZnO composite nanofiber film that subsequently caused changes in the transmitted light loss. Temperature changes caused a shift in the center wavelength of the FBG. Experimental results showed that the humidity and temperature sensitivities of the proposed sensor coated with the PVA/nano-ZnO composite film were −0.02539 dB/%RH and 11.14 pm/℃, respectively. Compared with an optical fiber sensor using a PVA film alone, the humidity sensitivity of the proposed sensor was increased by nearly four times after the addition of nano-ZnO.

Electrospinning of BCNNTs/PVA/PEDOT composite nanofibers films for research thermoelectric performance

AbstractIn recent years, the thermoelectric properties of one‐dimensional boron nitride nanomaterials have gradually attracted widespread attention of researchers in the world. In this paper, boron carbon nitrogen based composite nanofiber films were prepared by electrospinning. It is found that the diameter of nanofibers decreases in BCNNTs/PVA/PEDOT composite films when electrospinning voltage rises, while diameter increases as PVA and BCNNTs concentration increase of electrospinning precursor solution. Finally, thermoelectric power factor is investigated of the composite nanofiber films. It is verified that thermoelectric properties of the films closely related to electrospinning quality. However, fiber density of single‐layer BCNNTs/PVA/PEDOT nanofiber film is too low, folding increase the density and thickness of multilayer BCNNTs/PVA/PEDOT nanocomposite fiber films, and the thermoelectric characteristics are significantly improved. The Seebeck coefficient can reach 3.62 mV/K and the power factor is 29.09 nW/mK2.

Preparation and electrochromic properties of flexible transparent WO3/AgNW-decorated nanofiber composite film

It is well-known that tungsten oxide (WO3) is extensively used for electrochromic (EC) devices due to its special properties, such as high coloration/bleaching response time, good coloration efficiency, etc. The preparation of flexible EC devices is highly desirable for various applications. However, the fabrication of flexible EC devices with improved performance is still a major task due to their limited experimental protocols. In this study, we have prepared highly flexible transparent films consisting of WO3 and silver nanowires coated on nanofiber-reinforced composite films (WO3/AgNW-NCF). A novel flexible transparent WO3/AgNW-NCF is used for EC applications. The as-fabricated EC device based on WO3/AgNW-NCF demonstrated good coloration efficiency (161.3 cm2 C−1), excellent stability (81.5%) and rapid response time for coloration (2.9 s) and bleaching (3.2 s). The fabricated transparent flexible EC device may potentially be useful for designing an outstanding EC device for smart window applications.

Vancomycin-Loaded Polycaprolactone Electrospinning Nanofibers Modulate the Airway Interfaces to Restrain Tracheal Stenosis.

Site-specific release of therapeutics at the infected trachea remains a great challenge in clinic. This work aimed to develop a series of vancomycin (VA)-loaded polycaprolactone (PCL) composite nanofiber films (PVNF-n, n = 0, 1, and 5, respectively) via the electrospinning technique. The physiochemical and biological properties of PVNF-n were evaluated by a series of tests, such as FT-IR, XRD, SEM-EDS, and antibacterial assay. The PVNF-n samples displayed a typical network structure of fibers with random directions. VA was successfully introduced into the PCL nanofibers and could be sustained and released. More importantly, PVNF-5 showed relatively good antibacterial activity against both methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae (SPn). Thus, PVNF-5 was covered onto the self-expandable metallic stent and then implanted into a New Zealand rabbit model to repair tracheal stenosis. Compared to a metallic stent, a commercial pellosil matrix–covered stent, and a PVNF-0–covered metallic stent, the PVNF-5–covered airway stent showed reduced granulation tissue thickness, collagen density, α-SMA, CD68, TNF-α, IL-1, and IL-6 expression. In conclusion, this work provides an anti-infection film–covered airway stent that in site restrains tracheal stenosis.

Interfacial crosslinking for highly thermally conductive and mechanically strong boron nitride/aramid nanofiber composite film

Always, the interfacial thermal resistance and the phonons scattering greatly restrict the further improvement of boron nitride nanosheets (BNNS)/polymer composites. Herein, the interfacial crosslinking approach was innovatively used to enhance the in-plane thermal conductivity (TC) and mechanical properties of the BNNS/ANFs composites. In order to achieve the interfacial crosslinking, the BNNS was aminated via melting functionalization with urea and the ANFs were activated by hydrolysis with phosphoric acid (PA). The nacre-like cross-linked aminated BNNS/reactive ANFs (C-ABNNs/R-ANFs) composite film was fabricated by vacuum-assisted filtration followed with interfacial crosslinked by condensation reaction with glutaraldehyde (GA). The interfacial crosslinking effectively reduced the interfacial thermal resistance and phonons scattering, simultaneously contributes to the stress transfer between ABNNs and R-ANFs. When the loading amount of ABNNs is 20 wt%, the in-plane TC of the C-ABNNs/R-ANFs composite film is ∼10.15 W m−1K−1 which is nearly two times higher than that of ABNNs/R-ANFs composite film (∼5.59 W m−1K−1).

Graphene Oxide/Nanofiber-Based Actuation Films with Moisture and Photothermal Stimulation Response for Remote Intelligent Control Applications.

The rapid development of intelligent technology and industry has induced higher requirements for multifunctional materials, especially intelligent materials with stimulus-responsive self-actuation behavior. In this study, a Cu@PVA-co-PE/GO composite actuation film, with an asymmetric sandwich structure, was prepared by attaching graphene oxide (GO) to the surface of a polyvinyl alcohol ethylene copolymer (PVA-co-PE) nanofiber composite film containing copper nanoparticles (Cu) through layer-on-layer adsorption. This unique structural design endowed the composite film with not only excellent structural stability but also different bending directions (in response to moisture and infrared light). The actuation performance shows that when the adsorption time was 4 h, the maximum bending angle of the Cu@PVA-co-PE/GO composite film was up to 90° within 5.99 s. Furthermore, the actuation behavior was stable after 100 cycles of reversible moisture stimulation. Additionally, the maximum actuation strain of the composite film was up to 1.35 MPa during the illumination time of 6.8 s and maintained an excellent stability for 400 s under continuous infrared stimulation of 0.53 W/cm2. The rapid and sensitive stimulus response of the Cu@PVA-co-PE/GO composite film exhibited self-actuation behavior under the remote control of moisture and infrared light. This, in turn, suggests prospects for wide applications in emerging technologies, such as intelligent switches, artificial muscles, intelligent medical treatment, and flexible robots.

Robust Biomimetic Nacreous Aramid Nanofiber Composite Films with Ultrahigh Thermal Conductivity by Introducing Graphene Oxide and Edge-Hydroxylated Boron Nitride Nanosheet.

Dielectric materials with excellent thermally conductive and mechanical properties can enable disruptive performance enhancement in the areas of advanced electronics and high-power devices. However, simultaneously achieving high thermal conductivity and mechanical strength for a single material remains a challenge. Herein, we report a new strategy for preparing mechanically strong and thermally conductive composite films by combining aramid nanofibers (ANFs) with graphene oxide (GO) and edge-hydroxylated boron nitride nanosheet (BNNS-OH) via a vacuum-assisted filtration and hot-pressing technique. The obtained ANF/GO/BNNS film exhibits an ultrahigh in-plane thermal conductivity of 33.4 Wm−1 K−1 at the loading of 10 wt.% GO and 50 wt.% BNNS-OH, which is 2080% higher than that of pure ANF film. The exceptional thermal conductivity results from the biomimetic nacreous “brick-and-mortar” layered structure of the composite film, in which favorable contacting and overlapping between the BNNS-OH and GO is generated, resulting in tightly packed thermal conduction networks. In addition, an outstanding tensile strength of 93.3 MPa is achieved for the composite film, owing to the special biomimetic nacreous structure as well as the strong π−π interactions and extensive hydrogen bonding between the GO and ANFs framework. Meanwhile, the obtained composite film displays excellent thermostability (Td = 555 °C, Tg > 400 °C) and electrical insulation (4.2 × 1014 Ω·cm). We believe that these findings shed some light on the design and fabrication of multifunctional materials for thermal management applications.

Synthesis of free-standing N-doping Si/SiC/C composite nanofiber film as superior lithium-ion batteries anode

This work shows a facile way of fabrication of high-performance anode material for lithium-ion batteries (LIBs). Electro-spun PAN nanofibers were firstly wrapped with mesoporous SiO2 via templating method to form a PAN@SiO2 composite nanofiber film. After magnesiothermic reduction and removal of unreacted SiO2 and byproduct, a free-standing N-doping Si/SiC/C composite nanofiber film was achieved. It can be directly applied as electrode material in LIBs without conductive additives, binders, and current collectors, and it exhibited high specific discharge capacity and good cycling stability, which was ascribed to its special composite composition and porous structure.

Flexible dielectric nanocomposite films based on chitin/boron nitride/copper calcium titanate with high energy density

The increasing environmental pollution produced by synthetic polymer stimulates a huge demand for new biodegradable dielectric materials stemming from bioresources. Herein, regenerated chitin (RCH)/boron nitride nanosheets (BNNS)/copper calcium titanate nanofiber (CCTO) composite films were fabricated by simple mixing in aqueous KOH/urea solution. The two-dimensional BNNS possess wide bandgap and excellent intrinsic insulating properties to reduce the dielectric loss, thus exhibiting a greatly enhanced breakdown strength. Simultaneously, CCTO with ultrahigh dielectric constant significantly improved the dielectric constant of these ternary composite films. Accordingly, an extremely high energy storage density of 9.27 J cm−3 was obtained when loaded with 6 wt% BNNS and 5 wt% CCTO. Moreover, a superhigh charge-discharge efficiency of about 80% was well-maintained even when the applied electric field reaches 440 MV m−1. Furthermore, the ternary composite films also possessed much better thermal and mechanical properties.

Physical and release properties of poly(lactic acid)/nanosilver-decorated cellulose, chitosan and lignocellulose nanofiber composite films

AgNPs-decorated natural polymer nanofibers were successfully incorporated into the PLA matrix to achieve reinforced and active films. The effect of three different nanohybrids, composed of silver nanoparticles (AgNPs) and natural polymer nanofibers namely, cellulose (CNF), chitosan (CHNF), and lignocellulose (LCNF), on chemical, morphological, thermal, mechanical, physical, silver nanoparticles release and antimicrobial properties of PLA films was investigated. The compatibility of LCNF with PLA matrix in contrast with other nanofibers led to better miscibility and strong interactions, as confirmed by FT-IR. Large cracks and aggregation of CNF-AgNPs were detected in the morphological study; however, CHNF–AgNPS and LCNF-AgNPs had lower aggregated particles. Results obtained from XRD and TGA analysis indicated that none of the nanohybrids fundamentally influenced the crystalline structure and thermal stability of the PLA films. The mechanical strength of the PLA films loaded with LCNF-AgNPs and CHNF-AgNPs was significantly (p < 0.05) promoted due to the reinforcing impact of these nanofillers. Besides, the PLA/AgNPs-decorated LCNF films showed lower water vapor permeability and higher surface hydrophobicity. The PLA films incorporated with AgNPs-decorated nanofibers provided antimicrobial activity against food-borne pathogens and suitable release of AgNPs below normative limits, thereby proposing the potential of nanocomposites for antimicrobial active food packaging.

Effect of low energy Li-negative ions irradiation on electrochemically synthesized Copper nanoflakes/Polyaniline nanofibers composite thin film

Multi cathode source of negative ions cesium sputtering unit is used for irradiation of 50 keV Li-negative ions with varying fluences from 5 × 1011 to 5 × 1014 ions/cm2 on polyaniline nanofibers and copper nanoflakes/polyaniline nanofibers composite thin films. The X-ray diffraction pattern of polyaniline nanofibers thin film shows the broad peak at 2θ≈25.36° which is the characteristic peak of polyaniline and the X-ray diffraction pattern of copper nanoflakes/polyaniline nanofibers show a prominent peak at 2θ≈50.66° which confirmed the presence of copper. Fourier transform infrared spectra confirmed the formation of polyaniline thin films with characteristics absorption band at 1438 cm−1 for a benzenoid ring of polyaniline backbone, which shifted slightly after irradiation. Polyaniline nanofibers and copper nanoflakes/polyaniline nanofibers composite thin films confirmed hydrophobic nature and the contact angle changes insignificantly after irradiation. Field emission scanning electron microscope images of polyaniline nanofibers and copper nanoflakes/polyaniline nanofibers composite thin films show the nanofibrous network of the diameters ranging from 50 nm to 60 nm and the copper nanoflakes get deposited uniformly on the polyaniline nanofibers. From the application point of view, this work might provide strong evidence to use negative ion irradiation for creating defects in polyaniline nanofibers and copper nanoflakes/polyaniline nanofibers composite thin films and it would attract wide attention towards their use in sensing, electronic devices, and energy storage device applications.