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In the present study, a fluorescent optosensor containing a molecularly imprinted polymer in combination with electrospinning was employed for selective recognition of 2,4-dichlorophenoxyacetic acid (2,4-D). Free radical polymerization was carried out on the surface of polyethersulfone (PES) nanofibers as a substrate using a monomer, initiator, template and a polymerizable 1,8-naphthalimide derivative as the fluorogenic monomer. PES nanofiber@fluorescent molecularly imprinted polymer (PES nanofiber@FMIP) was produced by means of UV curing. The magnetic PES nanofiber@FMIP was developed in the same manner as the magnetic Fe3O4 nanoparticles were exerted in the electrospinning of the PES nanofiber. The imprinting factor (IF) was considered 1.97 as a selective character of PES nanofiber@FMIP versus PES nanofiber@FNIP. The developed sensor was able to selectively determine 2,4-D in a linear range of 1 × 10−7-1 × 10−3 M with limit of detection (LOD) of 1.01 × 10−8 M. The results confirmed that PES nanofiber@FMIP was satisfactorily able to determine trace concentrations of 2,4-D.

Membrane separation technology is widely used in water treatment. In this paper, we prepared polyphenylene sulfide/porous carbon nanofibers (PPS/PCNF) hybrid membranes by adding PCNF into PPS membranes. In the thermally induced phase separation (TIPS) process, PCNF could migrate to the top surfaces of the hybrid membranes, which made the pore size on the top surfaces of the membranes significantly decreasing and the pore size distribution became narrower. Compared with the conventional surface coating modified membranes, the surface coating material of PCNF would not falling off from PPS membrane, and it made the hybrid membranes to become more hydrophobic and to have the higher breaking elongation. PCNF, as a kind of heterogeneous nucleating agent, increased the melting temperature and the crystallization temperature of PPS/PCNF membrane, which resulted in PPS/PCNF membrane having the higher breaking elongation. Most importantly, PPS/PCNF hybrid membranes had a good intercepting performance, with bovine serum protein (BSA) intercepting rate of 92.7% and dye methylene blue (MLB) intercepting rate of 99.9%. Meanwhile, they also had a good removal effect on bacteria in strong polar organic solvent, and the removal rate achieved 93.7%. Thus, the PCNF hybridized PPS can play a crucial role on wastewater treatment in the future.

Polypyrrole was prepared in the presence of cationic dyes, safranin and phenosafranin. The safranin supported the one-dimensional growth of polypyrrole, converting globules to nanorods and later also to nanotubes, particularly at higher dye concentrations. In the case of phenosafranin, the produced nanotubes were considerably thicker and were always accompanied by globules. Upon oxidation both dyes are expected to generate insoluble oligomeric templates that serve as loci for the deposition of polypyrrole. The formation of globular morphology takes place when the dye becomes depleted, due to its low concentration for safranin, or because of robust templates produced by phenosafranin. In addition to scanning and transmission electron microscopies, the resultant polypyrroles were characterized by FTIR and Raman spectroscopies, and DC conductivity measurements. The conversion of globular morphology to nanotubes/nanofibers was accompanied by the increase in conductivity from 5 to 35 S cm−1, which was explained by the improved ordering of polypyrrole chains more preferable for charge transport. The series of syntheses at varying oxidant-to-pyrrole mole ratios confirmed the stoichiometric ratio 2.5 to be the best for pyrrole oxidation but a good stability of polypyrrole was demonstrated even at extremely high stoichiometric ratio 15.

Nanofibers of Al2O3 (commercial product Nafen™), which were modified by various silane coupling agents have been used to create hybrid materials based on copolymer of ethylene and propylene. Nanocomposites were obtained by in situ catalytic copolymerization on the rac-Et(2-MeInd)2ZrMe2/isobutylalumoxane system. Trialkoxysilanes with alkenyl (vinyl and octenyl) and alkyl (octyl) functional groups were used for modification. CP MAS NMR analysis (13C and 29Si) of all modified nanoparticles showed the absence of residual alkoxy groups and allowed to identify the type of formed siloxane groups (mainly T2, T3). EDX analysis of trimethoxyalkenylsilanes modified nanoparticles showed significant contribution of self-condensation reactions, otherwise, in the case of triethoxyoctylsilane condensation with surface Al OH groups prevailed. It is found that octylsilane modification leads to remarkable improvement of mechanical properties (tensile strength - approx. 150%, elongation at break - approx. 50% with regard to neat copolymer) at low nanofiller dosage (0.63 wt %), significantly exceeding those for the materials with alkenylsilane treated nanofibers. In the case of octenylsilane even major decline in mechanical performance was observed. We believe that this behavior is determined by the distribution of nanofiller in the polymer matrix, which is markedly different for different surface treatments. TEM observations show that octylsilane modification leads to efficient dispersion of Nafen in polymer matrix, while the use of alkenylsilanes leads to partial or significant aggregation of Nafen particles.

Mechanical properties of ultra-fine polymeric nanofibers are highly size-dependent and the mechanisms for causality of the size dependency is still not quite clear yet. In this work, we investigate the origins of this size dependency at the atomistic level. By using molecular dynamics (MD) framework, two fabrication methods are utilized in this study to prepare non-drawn and hot-drawn fibers, in order to investigate the two distinguished mechanisms for nanofiber size dependency. One is rooted in the effect of surface chains which is intrinsic to low dimensional materials and the other is the chain alignment induced by drawing during fiber fabrication process. Our results show that the size dependency is not chiefly attributed to the effect of surface polymeric chains, but rather strongly relates to the chain alignment in nanofiber's microstructure. The atomistic study shows that non-drawn nanofibers have a dense core covered by a less dense shell layer, but interestingly, our investigations reveal that the core-shell structure itself will not result in the remarkable increase of modulus and strength when diameter of the fiber drops down. By testing the hot-drawn fibers, we found the size dependency mainly originates from the chain alignment. When fiber is formed by hot-drawing, higher drawing ratio leads to thinner fiber and more aligned chains in the microstructure. A three-fold increase of modulus and strength is observed when the chain orientation parameter of the hot-drawn nanofiber increases from 0.1491 to 0.3375 while the diameter of the fiber drops from 19 to 10 nm. By examining the energy evolution associated with the bond lengths, bond angles and dihedral angles at the atomistic scale, our results show that the dihedral angles play a vital role in the size-effect. Our results also show the mechanical response of fibers are affected by changing the temperature, additionally, the orientation-induced crystallization is monitored on hot-drawn fibers at 300 K, which makes the fibers become stiffer but less ductile.

This study reports the effects of post-draw processing on the structural and functional properties of electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers. Previous studies have independently demonstrated the potential of the electrospinning process or the post-drawing process to enhance the piezoelectric properties of PVDF nanofiber, and thin film structures respectively. However, post drawing electrospun nanofibers has been difficult to achieve. To overcome this limitation, a parallel automated track device was implemented to post-draw thousands of individual PVDF-HFP electrospun nanofibers per minute. Relationships were established showing that yield strength, Young's modulus, and piezoelectric output were enhanced with increasing draw ratio. The normalized voltage output of PVDF-HFP nanofibers post-drawn to a draw ratio of 3 increased by four-fold compared to undrawn control. We hypothesize that polymer chain and crystal alignment in the direction of the fiber axis, which were increased by post drawing, resulted in enhanced voltage output of PVDF-HFP nanofibers under mechanical stimulation.

Correlations between observable features of the droplet-jet shape and the diameter of electrospun nanofiber were studied. Three shape parameters derived from optical images of the jet transforming from a droplet were identified. They are “L-R curvature”, “initial jet diameter”, and “transition slope”. Nanofiber diameter increased as the observed value of each shape parameter increased. The correlation between “initial jet diameter” and fiber diameter, as well as the correlation between “transition slope” and fiber diameter, were not affected by the variation of voltage or concentration of the polymer solution. “Initial jet diameter” and “transition slope” have potential applications in online controlled electrospinning to predict nanofiber diameter as real-time feedback information to guide the control of electrospun nanofiber diameter.

The rapid development of TE generators for harvesting energy from the human body has made new demand on its TE performance and wearability. In this context, electrospinning and in situ synthesis process are employed to fabricate Ag NPs coated PEDOT:PSS/PVA flexible self-supporting nanofiber film. The introduction of Ag NPs not only creates a great quantity of organic–inorganic interfaces which make an increase both in charge transfer channels and phonon scattering, but also greatly improve the mechanical properties of nanofiber film. As a result, the electrical conductivity has been greatly improved without losing too much Seebeck coefficient of the composite film, a maximum power factor up to 1.2 μW m−1 K−2 at room temperature is achieved. A flexible TE generator consisting of 5 strips is designed using the as-prepared composite film and can produce an output voltage of 3.43 mV at a 30.1 K temperature difference.

In this study, multi-scale micro/nano fibers membrane based on polypropylene and polystyrene were successfully fabricated by one-step melt-blown technique for high performance air filtration. The incompatibility of the used polymers made the viscosity of blended melt fluctuate continuously, resulting in the remarkable diameter difference occurred in prepared fibers. The micro-scale fibers acted as skeleton supports which could improve the permeability of melt-blown nonwovens, and the nano-scale fibers acted as connection props which could increase the surface area/volume ratio to improve the filtration performance by simply varying the composition of precursor solutions. And the obtained nonwovens showed the enhanced filtration efficiency and reduced pressure drop simultaneously, which included high air filtration efficiency of 99.87%, a low pressure drop of 37.73 Pa and a satisfactory quality factor of 0.18 Pa-1. The successful preparation of micro/nano fibers by the simple one-step method may develop novel filtration and separation materials to reduce air pollution.

In this work, we successfully prepared multifunctional boron nitride nanosheets (BNNS)/polyvinyl alcohol (PVA) nanofiber membranes. Using sulfanilic acid (SA) as a medium, hexagonal boron nitride (h-BN) were exfoliated into SA-functionalized BNNS through dry ball-milling process followed with liquid-phase exfoliation based on Lewis acid-base interaction. The f-BNNS/PVA composite nanofiber membranes with different loading amounts of f-BNNS were prepared through electrospinning. The results demonstrated the electrospun f-BNNS/PVA composite nanofiber membranes show high mechanical properties and thermal conductivities. The yield and ultimate tensile strengths of f-BNNS/PVA composite nanofiber membrane at 5 wt% loading amount can reach ∼8.56 and ∼11.37 MPa. Meantime, the thermal conductivity of f-BNNS/PVA composite nanofiber membrane with 10 wt% loading amounts of f-BNNS is ∼0.7328 W/(m•K), almost 6.47 times higher than that of neat PVA membrane. Besides, the f-BNNS/PVA composite nanofiber membrane can also be used as a filtration membrane for fast malachite green (MG) absorption and separation of MG and rhodamine B dyes.

Polyvinyl alcohol nanocomposite containing immobilized [Mn(Br4TPP)OAc] complex on bio inspired copper oxide was prepared by an electrospinning method (PVA@CuO-MnP). This novel heterogeneous biocatalyst based on Carthamus tinctorius plant was characterized by TEM, SEM, AFM, EDAX, elemental analysis and FTIR spectroscopy. Thermostability and amount of supported porphyrin complex on copper oxide loading on PVA was determined by thermogravimetric. This electrospun PVA@CuO-MnP nanofiber were estimated that the CuO-MnP had with average size of 70 nm distributing on PVA with the size between 65 and 80 nm. We first succeeded the new possibility of nanofiber applications in atom-efficient synthesis of bis (1H-indol-3-yl)methanes in excellent yields under solvent-free conditions. A structurally diverse set of aldehydes and 1H-indole or 2-methylindole was transformed into desired products regardless of the substituents electronic nature. The products were isolated easily from green media, and the catalyst could be reused several times without any appreciable decrease in catalytic activity.

Polyaniline (PANI) nanofibers were fabricated via an interfacial polymerization method at 0 °C by using 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and ammonium peroxysulfate as a dopant and an oxidant, respectively. The molar ratio of the oxidant to aniline monomer influenced the morphology (shape and size) of the resulting PANI/AMPSA nanofiber and was investigated using a scanning electron microscope and transmission electron microscope images. The conductivity of synthesized PANI/AMPSA nanofiber changed when its synthetic conditions were varied. Electrorheological (ER) performance with and without an electric field was tested for ER fluids composed of either PANI nanofibers or normal PANI. Both conventional Bingham and Cho-Choi-Jhon models were utilized to describe shear stress behavior as a function of shear rate, especially under a low shear rate range. Finally, the fibril morphology of PANI nanofibers showed a pronounced effect on the dispersion stability of the ER fluid by measuring the transmittance as a function of sedimentation time via an optical analyzer of Turbiscan.

The polymerization of aniline (AN) was assisted with an oligomer that possessed two amino end groups (2AO) in the presence of a single enantiomeric acid, (1S)-(+)-10-camphorsulfonic acid ((S) CSA). The reaction produced helical polyaniline (PANI) nanofibers with the opposite helical sense due to the concentration changes of (S) CSA in the polymerization system. The similar dependence of the circular dichroism (CD) signal on the (S) CSA concentration was also observed in the oxidization of the oligomer 2AO by ammonium persulfate (APS) in the presence of (S) CSA. In addition, under a certain (S) CSA concentration, the 2AO-assisted polymerization at low and high temperatures also produced the PANI fibers with the opposite helical sense. It is likely that these result from the different interaction modes of (S) CSA with the 2AO at different (S) CSA concentration. As a consequence, the oxidized 2AO (oligomer seeds) with different chirality in the early stage of the polymerization control the helicity of the resulting PANI nanofibers.

Optimization of chemical composition and topography is vital to obtain high-performance proton exchange membranes (PEMs). In this work, cellulose nanofibers were incorporated with phosphoric acid and embedded into the sulfonated poly (ether sulfone) (SPES) matrix to develop PEMs with improved proton conductivity by building proton transfer channels and providing additional proton transport sites. The morphology and chemical structure of the nanofibers doped with different phosphoric acid concentrations and the performance of the composite PEMs were characterized by multi-technics. The results showed that the thermal stability, water swelling ratio (SR) and proton conductivity of the composite membrane were improved in the phosphoric acid-doped cellulose nanofibers. The maximum conductivity (0.154 S/cm, 80 °C, 100 RH) was reached for composite membranes with cellulose nanofibers doped with 0.25 mol/L phosphoric acid. Hence, composite membranes containing proton-conducting cellulose nanofibers could be used to develop novel PEMs for fuel cells.

Recently, extraordinary attention has been given to the preparation of strong acid-doped polyaniline in distinct morphologies, such as nanofibers, nanotubes, and nanoflowers, while seeking proper and cheap energy polymeric materials. This work introduces the CO2-supported polymerization process as an advanced and novel polymerization technique to prepare rectangular cross-sectional self-assembled HCl-doped polyaniline nanotubes (HCl-PANNT) without the need to use any surfactants for the first time. Based on the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results, a rectangular cross-sectional HCl-PANNT with an average outer diameter and wall thickness of 110 and 35 nm, respectively, was prepared. Furthermore, X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were employed to reveal the crystallinity and the chemical structure of the prepared polyaniline, respectively. Accordingly, the produced PANNT has a partial crystalline structure and emeraldine salt form. Moreover, the produced HCl-PANNT showed a high electrical conductivity of 1.5 S/cm.

Solid-state drawing to high extension ratios of melt-extruded VGCF-iPP nanocomposite filaments results in remarkable increases in modulus and strength, which mask any contribution of nano-reinforcement or inter-particle confinement observed previously. Based on X-ray diffraction and thermal analyses it is shown that the drawing process involves crumpling of the original 'shish-kebab' structure, accompanied by lateral shrinkage of the 'kebabs', disappearance and reorientation of daughter lamellae and significant increases in the degree of crystallinity by solid-state recrystallization. The effects of the initial diameter of the as-extruded filaments and those of the nanofibers and the 'shish-kebab' structure are dominated by the drawing process, which produces a highly aligned fibrillar structure with superior mechanical properties. A cartoon model of the effect of solid-state drawing of extruded iPP and nanocomposite filaments on the transition from 'shish-kebab' to fibril morphology is presented.

This paper reports the effects of hydrogen bonding on the starch granule dissolution, spinnability of the starch solution, and the properties of the electrospun starch fibers. Dissolution behaviors of the starch granules in dimethyl sulfoxide (DMSO) and water mixed solvents are characterized by confocal laser microscope, differential scanning calorimetry (DSC), and rheologic measurement. The starch granules are dissolved in the 100%DMSO or 6%H2O/94%DMSO solvent, resulting in good electrospinnability. On the other hand, the gelatinization behavior is observed for the starch granules in the 22%H2O/78%DMSO solvent, resulting in poor fiber formation during electrospinning. Infrared spectroscopy, DSC, x-ray diffraction, and mechanical property characterizations of the electrospun starch nanofibers suggest that the water content in the solvent plays an important role in the properties of the nanofibers. The dissolution behavior, electrospinnability, and the properties of the electrospun nanofibers are explained by the effects of the DMSO and H2O molecules on the ubiquitous hydrogen bonds in starch.

Stereocomplex polylactide (sc-PLA) nanofibers with the average diameter of 367 nm were prepared by the conductivity-controlled electrospinning using 7 wt% PLA solution in the mixed solvents of dichloromethane and pyridine. The sc-PLA nanofibers were used as reinforcement materials for poly( l -lactide) (PLLA) to fabricate a self-reinforced PLA composite, while the fibers were compounded into the PLLA by compression molding. Thermomechanical and optical properties of the resulting self-reinforced PLA composites were investigated. It was found that highly transparent (above 75%) self-reinforced PLA composites were obtained up to the sc-PLA fiber concentration of 15 wt%. Also, at higher temperature in the rubbery state, the storage moduli of the composites increased by adding sc-PLA nanofibers. At the fiber concentration of 15 wt%, the storage modulus of the composite became 70 MPa, which was 24.1 times higher than that of the original pure PLLA. It was therefore concluded that the self-reinforced PLA composite with high transparency and high thermomechanical properties was successfully obtained.

Bio iron oxide was synthesized from natural Sesbania sesban plant and modified by a molybdenum complex (Fe2O3/MoSB). Fe2O3/MoSB was deposited on polyvinyl alcohol (PVA) using a conventional single nozzle electrospinning technique (PVA/Fe2O3/MoSB). TEM, SEM, AFM, FT-IR, TGA, EDAX, and elemental analysis were used to determine fiber compositional information. The catalytic efficiency of electrospun PVA/Fe2O3/MoSB nanofiber in the oxidation of alcohols was exploited. The green reactions were conducted at solvent free conditions as a green media in the presence of H2O2 to have the desired aldehydes and tert-butyl hydrogen peroxide to obtain acid products in high yields and excellent selectivity. The survival of this nanocomposite was investigated and it could be reused and recycled in consecutive runs.

To develop tissue engineering scaffolds that possess similar morphological structures to natural extracellular matrices (ECMs) is a major technological challenge. Herein, the feasibility of utilizing polycaprolactone (PCL) as biocompatible and biodegradable binding agent to fabricate electrospun three-dimensional (3D) scaffolds has been demonstrated. The obtained 3D scaffolds are soft while elastic, and they possess interconnected and hierarchically structured pores with sizes in the range from sub-microns to hundreds of microns; hence, they are morphologically similar to natural ECMs thus well suited for cell functions and tissue formation. It is envisioned that various thermoplastic polymers could be fabricated into 3D nanofibrous scaffolds/structures by first making blend nanofibers with PCL followed by processing via the thermally induced (nanofiber) self-agglomeration (TISA) method and finally being thermally stabilized, and the resulting electrospun 3D nanofibrous scaffolds/structures might to be useful for a variety of applications (particularly those related to tissue engineering).

Polydiacetylene (PDA) are polymers known to switch from blue to red when exposed to environmental stimuli. This paper reports on electrospun composite nanofibers of polyacrylonitrile (PAN) and a high temperature PDA. The effect of PAN on the thermal and thermochromic properties of the PDA was studied. PDA to PAN mass ratio in the composites was varied and an unusually high loading of 30 wt% PDA was achieved. Scanning and transmission electron microscopies (SEM, TEM) revealed a randomly-packed morphology of nanofibers with well dispersed PDA particles inside. Through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), the heat resistant PAN nanofibers were found to increase the reversible temperature range of the embedded PDA while also improving its thermal stability. Naked eye observations suggested that the composite thermochromic sensor can be reversed from temperatures around 200 °C - a big improvement from just 156 °C - while ultraviolet–visible spectroscopy (UV–vis) studies showed that there was a progressive deterioration of the conjugated PDA backbone which ultimately resulted in complete loss of reversibility and colorimetric character at 230 °C.

Melt blowing is the most common technique to directly produce nonwovens from polymeric resins without any demand for extra bonding steps. The relatively low diameter of meltblown fibers, 1–2 μm, makes them superior in separations performance to the competing melt processing technique, spun-bonding. To further decrease meltblown fiber diameter, the islands-in-the-sea approach was investigated in this study. Immiscible blends of a water-soluble polymer, sulfonated poly(ethylene terephthalate) (SP), and hydrophilic polybutylene terephthalate (PBT) and hydrophobic polyvinylidene fluoride (PVDF) were meltblown and the SP washed away to produce nanofibers of less than 200 nm diameter. Despite a significant increase in blend drop size upon increasing the minor phase fraction, ϕ, the nanofiber diameter increased only slightly. Thus, we conjecture that nanofiber diameter is mainly controlled by fiber pinch-off, induced by quick stretching during the melt blowing process, rather than being affected by initial drop size. At a high shear viscosity ratio, ηminor/ηmatrix > 3, nanofibers showed a higher level of irregularities, particularly when the polymer flow rate decreased. At ϕ ≥ 0.2 fiber bundling was observed but with nanofibers from PVDF, due to its lower surface energy, compared with PBT, bundling decreased. Our work shows that using polymers with relatively low surface energy, and thus low tendency for coalescence, coupled with low viscosity can result in nonwoven mats of fibers with very low average diameter, low bundling, and an acceptable fiber regularity. With PVDF we achieved a record low average diameter of 36 nm. By using a water-soluble polymer matrix, such as sulfonated poly(ethylene terephthalate), concerns about cost and environmental problems related to chemical solvents are alleviated.

In this study, electrospun nanofiber was continuously sandwiched between two rubber rollers at high temperature (150 °C). The prepared nanofiber support layer possessed a pore size of 0.4 μm (with narrow distribution) and a fiber diameter of 292 ± 94 nm. Afterward, an interfacial polymerization was employed to deposit the selective polyamide layer on the nanofiber support layer. For the first time, engineered osmosis (EO) was used as a platform for verifying the presence of a polyamide selective layer on a nanofiber support layer. We found that the membrane prepared exhibited an excellent combination of permeability (30 L/m2h) and selectivity (17 g/m2h and 0.57 g/L) under a net pressure of 49 bar at the EO platform. The membrane developed can be applied to generate renewable energy using the EO process. In addition, the EO method can be used to detect selective polymer having a nano-scale thickness.

In this study, a one-step electrospinning method was developed for the fabrication of polyamide nanofibrous mats with controllable structure and enhanced wetting behavior. The effects of the concentration of Triton X-100 as the surfactant, as well as formic acid and dichloromethane solvents on characteristics of electrospun nanofibrous mats were investigated. The fibers' diameter and pore size distribution of mats were deliberated by scanning electron microscopy. Furthermore, to characterize the wettability of fibers, the roughness of their surface was evaluated by atomic force microscopy along with measuring the droplets contact angle on the mats surface. The results revealed that adding the surfactant not only improved the electrospinning of nanofibers, but also increased the mat hydrophilicity. Furthermore, changing the polymer solvent altered the mat roughness and consequently its wettability. In general, adjusting the nanofibers' roughness and diameter, mat pore size distribution, and water contact angle could increase the water permeability through the mat.

Combining biocompatible polymers and bioactive molecules, holds promising potential as a bone substitute due to its favorable osteoinductivity. In the present study, graphene oxide (GO) and Zn-Curcumin complex (Zn-CUR) as a bioactive biomolecule were loaded into coaxial electrospun nanofibers, and the capacity of the Zn-CUR scaffolds was investigated for bone regeneration. The electrospun nanofiber scaffolds were characterized by SEM, TEM, and FT-IR spectroscopy. The SEM and TEM observations showed defect-free uniform coaxial nanofibers with about 153 nm diameter. The potential of the composite nanofibers as bone tissue scaffolds in terms of their biocompatibility and bioactivity were evaluated by MTT assay, alkaline phosphatase (ALP) activity, and alizarin red S (ARS) staining. Cellular morphology and MTT assay demonstrated that Zn-CUR containing nanofibers supplied better support cellular adhesion, spreading, and proliferation in comparison with drug-free nanofibers. Moreover, the addition of Zn-CUR complex to scaffolds increased ALP activity and the production of matrix mineralization. The Zn-CUR complex not only enhanced the osteogenic performance but also have an excellent antibacterial activity and therefore reduced postoperative infection. Overall, our study showed that the novel Zn-CUR composite nanofibers with enhanced osteogenic capacity and cytocompatibility offer a promising approach for bone tissue engineering.

A series of di-nuclear metal acetate complexes 1–6 incorporated by nitrogen heterocycle-containing salen-type ligands have been synthesized, structurally characterized and performed as catalysts to prepare biodegradable polycarbonates and polyesters. Their catalytic performances for copolymerization of carbon dioxide-epoxides or cyclic anhydride-epoxides were systematically examined. Bimetallic nickel(II) complexes 1, 2 and 5 were active catalysts for the alternating copolymerization of cyclohexene oxide (CHO) with CO2; di-nickel complex 1 was shown to be the most effective and selective, leading to obtaining poly(cyclohexene carbonate)s with the best efficiency among them. Moreover, complex 1 was also found to be versatile for the ring-opening copolymerization of CO2 with different cyclic epoxides to give the corresponding polycarbonates. Additionally, di-cobalt(II) analogs 3, 4 and 6 were efficient catalysts for the alternating copolymerization of CHO and phthalic anhydride (PA) under mild conditions. Based on the results of catalytic studies, complex 3 was demonstrated to be the most active one CHO-PA copolymerization, producing the polymeric products with a “controlled” manner involving controllable molecular weights and narrow polydispersity. Interestingly, Co complex 3 was also able to catalyze the copolymerization of PA with 4-vinyl-1,2-cyclohexene oxide to obtain the associated polyester with the vinyl functionality on the side chains, which was further functionalized with tertiary amine moieties via thiol-ene click functionalization and converted to nanofibers through electrospinning. Due to the incorporation of polar groups, the resulting tertiary amine-modified polyester nanofibers that exhibit an improved hydrophilic property relative to their un-modified counterpart have been considered to have high potential to be utilized as a new functional fiber material.

Polyurethane nanofibers functionalized by high amount of N-chloro hydantoin were prepared for the decontamination of chemical warfare agents. Azido-polyurethane was firstly synthesized using azido-polydiol with 4,4′-methylenebis(phenylisocyanate) and 1,4-butanediol via step-addition polymerization. Hydantoin was introduced into the polyurethane via click reaction, followed by electrospinning and chlorination to obtain the decontaminable fibers. This N-chlorinated hydantoin-polyurethane fiber is an active decontaminable species for 2-chloroethyl ethyl sulfide and demeton-S-methyl, the simulant of chemical warfare agent. The decontamination efficiency of each exhibits 69% and 16% for 2-chloroethyl ethyl sulfide and demeton-S-methyl, respectively, with molar ratio of 1/1 for 2 h at ambient condition. This N-chlorinated hydantoin-polyurethane fiber exhibited considerable potential as the decontaminable material against toxic chemical warfare agents.