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Bending multi-walled carbon nanotubes (MWCNTs) into rings and structuring them into aerogels is difficult. In this study, cellulose nanofiber (CNF)-MWCNT composite fibers with chain-ring structures were prepared by covalently interconnecting carboxylated CNF and aminated MWCNT by dehydration condensation, solving the problems of the formation of MWCNT aerogels and their phase separation during the compounding process and providing CNF-based aerogels with electrical conductivity. The covalently interconnected aerogels (CAs) had hierarchical porous structures with mechanical resilience and chain-ring fibers, which drove the CNF and MWCNT to form a continuous homogeneous network resulting in a high compression resistance of 269.02 kPa. The CA-based flexible all-solid-state supercapacitor had a quality specific capacitance of 114.8 F g

Carbon nanofiber-based supercapacitors have broad prospects in powering wearable electronics owing to their high specific capacity, fast charge/discharge process, along with long-cycling life. Herein, a poly(acrylonitrile-co-β-methylhydrogen itaconate) copolymer was prepared and used to synthesize flexible hollow carbon nanofibers (HCNFs) via an electrospinning method without breaking after multiple bending. Subsequently, the inner and outer surfaces of HCNFs were evenly covered with ordered needle-like polyaniline (PANI) through in-situ polymerization methods to obtain three-dimensional flexible HCNFs/PANI composites, which exhibited a high capacity 1196.7 F/g at 1 A/g and good cycling stability (90.1% retention at 5 A/g after 3000 cycles). The symmetrical supercapacitor based on the HCNFs/PANI composites also delivered an outstanding electrochemical performance with high energy/power density (60.28 Wh/kg at 1000 W/kg) and superior cycling durability (90% capacitance retention after at 5 A/g 3000 cycles), which confirmed that the HCNFs/PANI composites had a wide application potential in flexible energy storage devices.

The electrode materials with high pseudocapacitance can enhance the rate capability and cycling stability of lithium-ion storage devices. Herein, we fabricated MoS2 nanoflowers with ultra-large interlayer spacing on N-doped hollow multi- nanochannel carbon nanofibers (F2-MoS2/NHMCFs) as freestanding binder-free anodes for lithium-ion batteries (LIBs). The ultra-large interlayer spacing (0.78∼1.11 nm) of MoS2 nanoflowers can not only reduce the internal resistance, but also increase accessible active surface area, which ensures the fast Li+ intercalation and deintercalation. The NHMCFs with hollow and multi-nanochannel structure can accommodate the large internal strain and volume change during lithiation/delithiation process, it is beneficial to improving the cycling stability of LIBs. Benefiting from the above combined structure merits, the F2-MoS2/NHMCFs electrodes deliver a high rate capability 832 mA h g−1 at 10 A g−1 and ultralong cycling stability with 99.29 and 91.60 % capacity retention at 10 A g−1 after 1000 and 2000 cycles, respectively. It is one of the largest capacities and best cycling stability at 10 A g−1 ever reported to date, indicating the freestanding F2-MoS2/NHMCFs electrodes have potential applications in high power density LIBs.

The immunomodulatory effect of Acanthopanax senticosus polysaccharide (ASPS) on immunosuppressed chickens induced by cyclophosphamide (Cy) was observed in this study. Four hundred 7-day-old chickens were randomly divided into 4 groups: vaccinated control group (VC group), Cy-challenged control group (Cy group), Cy-challenged + low-dose ASPS group (ASPSL + Cy group), and Cy-challenged + high-dose ASPS group (ASPSH + Cy group). All groups except the VC group were injected with Cy at a dose of 80 mg/kg/day of BW for 3 successive days to induce immunosuppression. At the age of 10 d, the ASPSL + Cy group and ASPSH + Cy group were intramuscularly injected with 0.2 mL of ASPS at the dose of 100 and 200 mg/mL/day, respectively, once a day for 3 successive days. The Cy group was injected with saline solution in the same way as the 2 ASPS groups. At the age of 14 d, the chickens were vaccinated with Newcastle disease (ND) vaccine in all groups. On day 7, 14, 21, and 28 after the vaccination, BW, lymphocyte proliferation, the serum antibody titers of the ND vaccine, the proportion of CD4+ and CD8+ T lymphocytes, and the concentrations of interferon gamma and IL-2 were determined. The results showed that chickens were injected with Cy at a dose of 80 mg/kg of BW for 3 d displayed lower immune responses than the control group, indicating that the immunosuppressive model was successfully established. At most time points, both high and low doses of ASPS could significantly promote lymphocyte proliferation; enhance BW, antibody titers, and the proportion of CD4+ and CD8+ T lymphocytes; and raised the concentrations of interferon gamma and IL-2 in Cy-treated chickens compared with those in the Cy control group (P < 0.05). These results indicated that ASPS could resist immunosuppression induced by Cy and may be a new-type immune adjuvant to improve vaccination in normal and immunosuppressed chickens.

A bifunctional 3-aminocarbonyl-3-butenoic acid methyl ester (ABM) was used to prepare high molecular weight poly(acrylonitrile-co-3-aminocarbonyl-3-butenoic acid methyl ester) [P(AN-co-ABM)] by suspension polymerization in aqueous medium. The influence of ABM monomer feed ratios on the structure and stabilization of P(AN-co-ABM) was characterized by element analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Based on reactivity ratio calculation, the comonomer ABM possesses greater reactivity than acrylonitrile. The molecular weight of P(AN-co-ABM) in this work is 10 times larger, as compared to the one prepared by solution polymerization; it is the key to producing high-performance carbon fiber. The FTIR, XRD and DSC results illustrate that the stabilization of P(AN-co-ABM) is significantly improved as compared with PAN homopolymer and P(AN-AA-MA), for instance, lower initiation temperature, smaller cyclization activation energy (Ea), broadened exothermic peak and larger stabilization extent, due to the ionic cyclization initiated by ABM, which makes the resultant P(AN-co-ABM) a potential precursor for carbon fiber.

Bifunctional comonomer 2-methylenesuccinamic acid (MLA) was designed and synthesized to prepare acrylonitrile copolymer P (AN-co-MLA) using mixed solvent polymerization as a carbon fiber precursor. The effect of monomer feed ratios on the structure and stabilization were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), X-ray diffraction (XRD), proton nuclear magnetic (1H NMR), and differential scanning calorimetry (DSC) for the P (AN-co-MLA) copolymers. The results indicated that both the conversion and molecular weight of polymerization reduce gradually when the MLA content is increased in the feed and that bifunctional comonomer MLA possesses a larger reactivity ratio than acrylonitrile (AN). P (AN-co-MLA) shows improved stabilization compared to the PAN homopolymer and poly (acrylonitrile-acrylic acid-methacrylic acid) [P (AN-AA-MA)], showing features such as lower initiation temperature, smaller cyclic activation energy, wider exothermic peak, and a larger stabilization degree, which are due to the ionic cyclization reaction initiated by MLA, confirming that the as-prepared P (AN-co-MLA) is the potential precursor for high-performance carbon fiber.

Carbon fiber-based electrodes hold great potential application in flexible supercapacitors, however most of carbon fibers are fabricated by nonrenewable polyacrylonitrile. In this work, a 3D flexible cellulose-based carbon nanofiber (C-CNFs) networks were prepared by electrospinning and multi-step heat treatment using renewable cellulose as precursor; then NiCo2S4 nanosheets and nanospheres were uniformly coated on C-CNFs through one-step solvothermal method to obtain flexible C CNFs/NiCo2S4 electrodes for supercapacitor. Compared with the C-CNFs/NiCo2S4 nanospheres, C-CNFs/NiCo2S4 nanosheets achieve a higher specific capacitance of 1784 F g−1 at the current density of 1 A g−1 and possess lower resistance, which attributes to high specific surface area and low resistance of C CNFs/NiCo2S4 nanosheets. Meanwhile, the C-CNFs/NiCo2S4 nanosheets show excellent cyclic stability with 79.3% capacitance retention after 10,000 cycles at the large current density of 10 A g−1. Finally, all-solid-state symmetric supercapacitor (ASSC) assembled from C-CNFs/NiCo2S4 nanosheets exhibits the large energy density of 85.53 Wh kg−1 at the power density of 1200 W kg−1 and good cyclic stability with 63.4% capacitance retention after 5000 cycles at the current density of 4 A g−1. Four ASSCs in series can power a ‘DHU’ Logo consisted of 36 light emitting diodes, confirming the as-prepared flexible CNFs/NiCo2S4 nanosheets have promising application in portable electronic devices and smart wearable devices.

Exploring comwposite nanomaterials with novel and stable nanostructures is of great importance for high performance supercapacitors (SCs). Herein, the nanosheet-like XMoO4 (X=Ni, Co) were uniformly grown on the carbon submicrofibers (CMFs) by a facile hydrothermal route. The NiMoO4@CMFs exhibits higher specific capacitance of 1485.53 F g-1 and better cycling stability with 87.6% retention after 3000 cycles at 1 A g-1 than that of CoMoO4@CMFs (1407.1 F g-1, 80.6% retention after 3000 cycles at 1 A g-1). To further improve the electrochemical performance of NiMoO4@CMFs, the hollow porous carbon submicrofibers (HPCMFs) were designed and used as a substrate for NiMoO4. Benefiting from the hollow porous structure, the HPCMFs can provide large specific surface area for electrolyte permeating and supply more ion channels in the charge-discharge process. Therefore, the NiMoO4@HPCMFs exhibits a high specific capacitance of 1600.0 F g-1 at 1 A g-1 and good cycling stability of 90.7% retention after 3000 cycles. The all-solid stated symmetric supercapacitors (ASSCs) were directly assembled by using NiMoO4@HPCMFs as electrode without any additives, which shows good flexibility and a high energy density of 55.33 Wh kg-1 at a power density of 999.89 W kg-1. Moreover, five series ASSCs can light ‘DHU’ logo, indicating potential application prospect in wearable electronics.

Bifunctional comonomer 2-methylenesuccinamic acid (MLA) was designed and synthesized to prepare acrylonitrile copolymer P (AN-co-MLA) using mixed solvent polymerization as a carbon fiber precursor. The effect of monomer feed ratios on the structure and stabilization were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), X-ray diffraction (XRD), proton nuclear magnetic (1H NMR), and differential scanning calorimetry (DSC) for the P (AN-co-MLA) copolymers. The results indicated that both the conversion and molecular weight of polymerization reduce gradually when the MLA content is increased in the feed and that bifunctional comonomer MLA possesses a larger reactivity ratio than acrylonitrile (AN). P (AN-co-MLA) shows improved stabilization compared to the PAN homopolymer and poly (acrylonitrile-acrylic acid-methacrylic acid) [P (AN-AA-MA)], showing features such as lower initiation temperature, smaller cyclic activation energy, wider exothermic peak, and a larger stabilization degree, which are due to the ionic cyclization reaction initiated by MLA, confirming that the as-prepared P (AN-co-MLA) is the potential precursor for high-performance carbon fiber.

This paper is about the degradation of polyvinyl alcohol (PVA) in aqueous solutions using a H2O2/Mn(II) system. Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were applied to analyze the degradation products of PVA, and the results revealed that the backbone chain of PVA could be effectively broken and oxidized. Several unsaturated degradation products, including carboxylic acids, ketones, aldehydes, olefins, and alkynes were also detected and identified by gas chromatography-mass spectrometry (GC-MS), which indicated that higher treatment temperatures would considerably promote the generation of lower molecular weight degradation products. According to the work presented in this paper, the degradation efficiency of PVA increased from 55 % at 60 oC to 99 % at 90 oC after treatment when the initial PVA concentration was 5 %, at pH=3 with a H2O2 and Mn(II) dose of 100 ml/l and 0.6 mol/l, respectively. In addition, kinetic modeling indicated that the experimental results were best fitted by the Page-modified model with an activation energy of 48.78 kJ/mol.

Most of the hollow carbon submicro-fibers (HCSFs) reported today are made from polyacrylonitrile (PAN) homopolymer. The obtained HCSFs are fragile due to the poor stabilization and spinnability of PAN. In this study, a bifunctional comonomer, β-methylhydrogen itaconate (MHI), was synthesized to prepare poly(acrylonitrile- co-β-methylhydrogen itaconate) [P(AN- co-MHI)] copolymer, which was used as a precursor to produce HCSF by coaxial electrospinning. The stabilization of P(AN- co-MHI) was studied by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR); the structure of HCSFs was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM). The stabilization of P(AN- co-MHI) has been improved significantly by MHI with lower cyclization temperature, broadened peak and lower activation energy, which is beneficial to producing high-performance HCSFs. HCSFs with fine and uniform structures were obtained after stabilization and carbonization; the diameter of the HCSFs shrinks due to the elimination of N and the extra H. The diameter and wall thickness of HCSFs can be controlled simply by the feeding ratio of P(AN- co-MHI) solution/styrene- co-acrylonitrile solution. The resultant HCSFs can be bent more than 280° without breaking, which has potential applications in lithium-ion rechargeable batteries, supercapacitors, fuel cells, and catalyst.

In order to improve the pre-oxidation performance and molecular weight of polyacrylonitrile (PAN). In this work, 3-aminocarbonyl-3-butenoic acid methyl ester) (ABM) was used as comonomers to formulate high molecular weight poly(acrylonitrile-co-3-amino-carbonyl-3-butenoic acid methyl ester) [P(AN-co-ABM)] copolymer by radical polymerization in the mixed solvent of dimethyl sulfoxide/deionized water =60/40 (wt/wt). The highest molecular weight of resultant P(AN-co-ABM) is 4.87 × 105 g/mol, 5 times larger than that prepared by solution polymerization under the same reaction conditions. The monomer reactivity ratios are calculated by Fineman-Ross and Kelen-Tudos methods based on the elemental analysis results. Thermal properties of P(AN-co-ABM) copolymer with different monomer feed ratios were studied by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry in detail. The results show that the stabilization of P(AN-co-ABM) has been significantly improved by ABM, confirmed by the lower initiation temperature and broader exothermic peak in DSC curves, larger extent of stabilization from FTIR and XRD studies, and smaller Ea of cyclization, which is due to the initiation of ABM through ionic mechanism. This study clearly shows that high molecular weight P(AN-co-ABM) copolymer is a better material for carbon fiber precursor.

Chemically converted graphene fiber-shaped supercapacitors (FSSCs) are highly promising flexible energy storage devices for wearable electronics. However, the ultralow specific capacitance and poor rate performance severely hamper their practical applications. They are caused by severe stacking of graphene nanosheets and tortuous ion diffusion path in graphene-based electrodes; thus, the ultralow utilization of graphene has been rarely carefully considered to date. Here, we address these issues by developing three-dimensional hierarchically porous graphene fiber with the incorporation of holey graphene for efficient utilization of graphene to achieve fast charge diffusion and good charge storage capability. Without deterioration in electrical but robust mechanical properties, the optimal graphene fiber shows ultrahigh specific capacitance of 220.1 F cm

A novel bifunctional comonomer 2-methylenesuccinamic acid (MLA) was synthesized to prepare poly(acrylonitrile-co-2-methylenesuccinamic acid) [P(AN-co-MLA)] copolymers, which can improve the stabilization of polyacrylonitrile significantly as a carbon fiber precursor. The structure and stabilization of P(AN-co-MLA) copolymers with different monomer feed ratios of AN/MLA were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Reactivity ratio studies shows that MLA possesses higher reactivity than AN, resulting in higher MLA content in P(AN-co-MLA) copolymers than in the feed. The molecular weight and conversion of copolymer decrease gradually with the increase of MLA content in the feed. Comparing with PAN homopolymer, P(AN-co-MLA) copolymer has two or even three exothermic peaks, and the initial temperature of P(AN-co-MLA) copolymer is ca. 70 °C lower than that of PAN, which broadens the exothermic peak. The ΔH/ΔT reduces from 34.01 J g−1 °C−1 to less than 17.67 J g−1 °C−1, confirming that the incorporation of MLA can avoid centralized heat release effectively. In addition, the extent of stabilization increases as the MLA content in P(AN-co-MLA) copolymer increases under the same heat treatment conditions. The activation energy (Ea) calculation shows cyclization Ea of P(AN-co-MLA) reduces from ca. 168 kJ mol−1 to ca. 110 kJ mol−1, it is concluded that synthesized comonomer MLA can significantly improve stabilization of PAN, which is conducive to the preparation of high performance carbon fiber.

Herein, three flexible 3D-interconnected N-doped carbon nanofibers (NCFs), multi-nanochannel carbon nanofibers (NMCFs) and hollow multi-nanochannel carbon nanofibers (NHMCFs) networks were prepared through simple electrospinning, then ultrathin MoSe2 nanosheets were vertically grown on the surface of carbon nanofibers (both inner and outer surface for NHMCFs) using a facial hydrothermal method. The resultant MoSe2 composites were directly employed as freestanding anodes for LIBs without any additives. The effect of carbon nanofiber structure on LIBs is studied in detail. The 3D networks of carbon nanofiber provide a continuous electrons transportation pathway, and the multi-nanochannel structure in NMCFs and NHMCFs can alleviate the volume changes during charge–discharge process. Both the inner and outer surfaces of NHMCFs are uniformly coated by MoSe2 nanosheets, thus the mass loading of MoSe2 in NHMCFs/MoSe2 increases 21.25% and 13.85% compared with NCFs/MoSe2 and NMCFs/MoSe2 electrode, respectively. The robust hollow multi-nanochannel structure of NHMCFs can not only increase the contact area between active materials and electrolytes but also shorten the Li+ diffusion pathway. Therefore, the NHMCFs/MoSe2 delivers the highest capacity of 586.7 mAh g−1 among three electrodes after 400 cycles at 1 A g−1, which is 3.54 times of NCFs/MoSe2 and 2.49 times of NMCFs/MoSe2, confirming that NHMCFs is a promising electrode substrate for LIBs.

Carbon nanofiber-based supercapacitors hold great promise for powering wearable electronics due to their high specific density, fast charge/discharge rate and ultralong cycling life. However, the most common polyacrylonitrile-based carbon nanofiber (CNF) is fragile and easy to break, which limits their practical application. Herein, a poly(acrylonitrile-co-β-methylhydrogen itaconate) copolymer is synthesized and used as precursor to prepare flexible hollow carbon nanofiber (HCNF) by coaxial electrospinning, which can be bended freely without breaking. Then, the ultrathin honeycomb-like MnO2 is coated uniformly on the inner and outer surface of HCNF by in-situ reduction method to prepare freestanding flexible 3D HCNF/MnO2 networks. The HCNF/MnO2 electrode exhibits high capacity 587.5 F g−1 at 0.5 A g−1 and good cycling stability 78.96% retention after 5000 cycles. The HCNF/MnO2 composite is directly utilized to fabricate symmetric all-solid-state symmetric supercapacitors (ASSCs) without using any current collector or binders. The ASSC exhibits a maximum specific energy of 59.15 Wh kg−1 at a specific power of 1575 W kg−1. Four ASSC in series can power a ‘DHU’ Logo consisted of 36 light emitting diodes, confirming the lightweight flexible HCNF/MnO2 based flexible ASSCs have great potential application in wearable and portable electronics.

SrAl2O4:Eu2+, Dy3+/light conversion agent is a new composite luminescent material, which can emit red light in the darkness after being excited. The SrAl2O4:Eu2+, Dy3+ was prepared by means of solid-state reaction, and SrAl2O4:Eu2+, Dy3+/light conversion agent was fabricated by combining light conversion agent on to SrAl2O4:Eu2+, Dy3+ particles. In order to promote the afterglow properties of this red-emitting phosphors, several kinds of SrAl2O4:Eu2+, Dy3+/light conversion agent containing different light conversion agent were artificially manufactured, and the effect of manufacturing elements including the concentration of light conversion agent and environmental factor of heating temperature, drying temperature, stirring time on its luminescence property were investigated through evaluating their afterglow properties. The results showed that the light conversion agent and manufacturing process did not destroy the phase of SrAl2O4:Eu2+, Dy3+, and the red light were not emitted by SrAl2O4:Eu2+, Dy3+ just for the energy transferred from SrAl2O4:Eu2+, Dy3+ to light conversion agent. And the affecting factors of light conversion agent concentration, heating temperature, drying temperature, stirring time had different influence on the afterglow property of SrAl2O4:Eu2+, Dy3+/light conversion agent with increasing the concentration of light conversion agent, heating temperature, drying temperature, stirring time, the afterglow time and initial brightness of this phosphor increased and then decreased gradually.

Novel intelligent cellulose/4-vinyl-phenylboronic acid (VPBA) composite bio-hydrogels with glucose and pH-responsiveness were successfully prepared via electron beam irradiation technology at room temperature. The composites were characterized by Fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectroscopy (XPS). The electron beam irradiation results in the appearance of carbonyl in the polymerization of 4-ethenyl-phenylboronic acid, grafting and cross linking reaction in composites, and a novel composite hydrogel was formed between the poly-4-ethenyl-phenylboronic acid and cellulose matrix. By means of the incorporation of phenylboronic acid groups, the composite hydrogels with pH and glucose responsive properties was produced, and glucose responsive properties were investigated by the self-regulation of insulin release of composite hydrogel through a serial glucose solution with different concentrations, which is having great potential applications in many fields.

Ir-catalyzed arylation, alkylation of quinones with boronic acids was developed under room temperature. Both aryl and alkyl boronic acids are suitable for this transformation. This expands the application scope of the iridium catalyst. This is also an excellent proof that iridium catalysts can be used in the C–C coupling of quinones and naphthoquinones with alkyl boronic acids.

In this work, a 3D flexible freestanding nitrogen-doped carbon nanofiber/MoS2 nanoflowers (NCNFs/MoS2) network with expanded interlayer spacing is fabricated by facile electrospinning and hydrothermal synthesis method, which is employed as flexible free-standing anodes for lithium-ion batteries (LIBs) without any additives. A poly(acrylonitrile-co-β-methylhydrogen itaconate) copolymer is synthesized and uses as a precursor to improve the conductivity and flexibility of NCNFs. The three-dimensional open structure of NCNFs/MoS2 provides a highly conductive pathway for fast transfer of charge and electron, and expanded interlayer spacing of MoS2 nanoflowers can increase available surface active sites for Li-ion and reduce the obstacle of Li-ion migration during lithiation/delithiation process. Moreover, it can relieve large internal stress and accommodates volume change during cycling. The NCNFs/MoS2 composite delivers a high capacity of 1168.6 mA h g−1 at a current density of 5A g−1 and an excellent reversible capacity retention of 94.49% after 1000 cycles (only 0.055‰ decay per cycle), which makes it one of the highest capacities and best cycling stability ever reported to date. It also exhibits a superior rate capacity of 909.5 mA h g−1 at current densities 10A g−1, indicating the 3D flexible freestanding NCNFs/MoS2 composite network has potential application in high-performance lithium-ion batteries.

This work aimed at effectively utilizing the chemically depolymerized waste poly(ethylene terephthalate) (PET) fibers into useful products for the textile industry. PET fibers were glycolytically degraded by excess ethylene glycol as depolymerizing agent and zinc acetate dihydrate as catalyst. The glycolysis product, bis(2-hydroxyethyl) terephthalate (BHET), was purified through repeated crystallization to get an average yield above 80%. Then, BHET was nitrated, reduced, and azotized to get diazonium salt. Finally, the produced diazonium salt was coupled with 1-(4-sulfophenyl)-3-methyl-5-pyrazolone to get azo dyestuff. The structures of BHET and azo dyestuff were identified by FTIR and 1 H NMR spectra and elemental analysis. Nylon filaments dyed by the synthesized azo dyestuff with the dye bath pH from 4.14 to 5.88 showed bright yellow color. The performances of the dyestuff were described with dye uptake, color fastness, K / S , L *, a *, b *, and Δ E * values.

In this study, waste poly(ethylene terephthalate) (PET) fibers were chemically recycled into azo disperse dyestuffs. First, waste PET fibers were glycolytically degraded by excess ethylene glycol utilizing zinc acetate dehydrate as a catalyst. The glycolysis product, bis(2-hydroxyethyl) terephthalate (BHET), was purified through recrystallization and hydrolyzed into terephthalic acid (TPA). Thereafter, BHET and TPA were nitrated, reduced and azotized to obtain diazonium salts. Finally, the obtained diazonium salts were coupled with N,N-dimethylaniline to obtain azo disperse dyestuffs (dye A and dye B, respectively). The depolymerized products (BHET and TPA) and azo disperse dyestuffs (dyes A and B) were characterized by FTIR and 1H NMR spectroscopy. Nylon and polyester filaments were dyed with the synthesized azo dyestuffs with the dye bath pH ranging from 3.6 to 5.8. The performances of the dyestuffs were described by maximum absorption wavelength, K/S, L*, a* and b* values.

In order to improve the stabilization and spinnability of polyacrylonitrile, a bifunctional comonomer containing both ester and amide groups was synthesized to prepare poly(acrylonitrile- co -3-aminocarbonyl-3-butenoic acid methyl ester) [P(AN- co -ABM)] copolymers used as the carbon fiber precursor instead of poly(acrylonitrile-acrylamide-methyl acrylate) [P(AN-AM-MA)] terpolymer. The differential scanning calorimetry and thermogravimetry results show that the stabilization of P(AN- co -ABM) have been remarkably improved by ABM compared with P(AN-AM-MA) terpolymer, such as lower initiation temperature, broadened exothermic peak and smaller activation energy. Moreover, the spinnability of P(AN- co -ABM) is also improved by ABM due to the lubrication of ester groups in ABM. This study clearly shows that P(AN- co -ABM) copolymer is a better material for use as a carbon fiber precursor than P(AN-AM-MA) terpolymer.

Cyclic voltammetry of ferrocene at glassy carbon electrode in acetonitrile (ACN), ο-nitrophenyloctylether (NPOE) and ACN-NPOE mixture with 0.2 M tetrabutylammonium tetrafluoroborate (TBABF4) were investigated. Both cathodic and anodic peak current were diffusion-controlled at any NPOE fraction. However, the peak current was decreased with the increasing NPOE fraction. In addition, the peak potential difference increased not only with an increase in the NPOE fraction but also in the scan rate, while the values of half-wave potential did not vary largely with the fraction or the scan rate. This indicated that the variation of peak current and peak potential should be due to the variation of the solution resistance. In order to demonstrate this assumption, the conductance of TBABF4 in ACN, NPOE, and ACN-NPOE mixture were determined by AC impedance. All of the solution conductances were inversely linear to the viscosity of the solvent, which was increased with the fraction of NPOE. The calculated ionization constant of TBABF4 in ACN was 2.8 times of that in NPOE. TBABF4 in ACN can work as a supporting electrolyte, whereas they work partly in NPOE.

A bifunctional comonomer 3-aminocarbonyl-3-butenoic acid methyl ester (ABM) was designed and synthesized to prepare poly(acrylonitrile-co-3-aminocarbonyl-3-butenoic acid methyl ester) [P(AN-co-ABM)] copolymer which can be used as carbon fiber precursor instead of poly(acrylonitrile–acrylamide–methyl acrylate) [P(AN–AM–MA)] terpolymer. The stabilization mechanism and structural evolution of P(AN-co-ABM) and P(AN–AM–MA) during stabilization were studied by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The activation energy (Ea) of the cyclization reactions was calculated by Kissinger method and Ozawa method. The results show that the stabilization of P(AN-co-ABM) has been remarkably improved by ABM compared with P(AN–AM–MA) terpolymer, such as lower initiation temperature, broadened exothermic peak, larger extent of stabilization, and smaller Ea of cyclization, which is attributed to the initiation of ABM through ionic mechanism. Moreover, the spinnability of P(AN-co-ABM) is also improved by ABM due to the lubrication of ester groups in ABM. This study clearly shows that P(AN-co-ABM) copolymer is a better material used as carbon fiber precursor than P(AN–AM–MA) terpolymer.

In order to replace terpolymer with bipolymer, a bifunctional comonomer β-methylhydrogen itaconate (MHI) containing carboxyl group and ester group was synthesized to prepare poly[acrylonitrile-co-(β-methylhydrogen itaconate)] [P(AN-co-MHI)] bipolymers used as carbon fiber precursor for improving the stabilization and spinnability at the same time. The P(AN-co-MHI) bipolymers with different monomer feed ratios were characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results show that both the polymerization conversion and molecular mass of P(AN-co-MHI) reduce with the increasing MHI amounts in the feed due to the larger molecular volume of MHI than acrylonitrile (AN). The monomer reactivity ratios were calculated by Fineman–Ross and Kelen–Tudos methods, the results show good agreement and MHI possesses higher reactivity than AN. Two parameters \( E_{\text{s}} = A_{{1,629\,{\text{cm}}^{ - 1} }} /A_{{2,244\,{\text{cm}}^{ - 1} }} \) and \( SI = (I_{0} - I_{\text{S}} )/I_{0} \) were defined to evaluate the extent of stabilization, and the activation energy (Ea) of the cyclization was calculated by Kissinger method and Ozawa method. The FTIR, XRD, and DSC results show that P(AN-co-MHI) bipolymers exhibit significantly improved stabilization characteristics than PAN homopolymer, such as larger extent of stabilization, lower initiation temperature, and smaller Ea of cyclization, which is attributed to the ionic initiation by MHI comonomer and it is beneficial to preparing high-performance carbon fiber.

A bifunctional comonomer β-methylhydrogen itaconate was synthesized to prepare high molecular weight poly [acrylonitrile-co-(β-methylhydrogen itaconate)] [P (AN-co-MHI)] by mixed solvents polymerization, which was used as carbon fiber precursor instead of acrylonitrile terpolymers. The effect of dimethyl sulfoxide (DMSO)/deionized water ratios on the polymerization, structure and stabilization of P (AN-co-MHI) was studied by elemental analysis, UV-Visible Spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The highest viscosity-average molecular weight (76.72 × 104 g/mol) of P(AN-co-MHI) was obtained in the mixed solvents of DMSO/deionized water = 10/90 (wt/wt) due to the zero chain transfer constant of deionized water for radical ~ ~ ~AN·, which is 10 times larger than that of P(AN-co-MHI) copolymers prepared in DMSO solution polymerization under the same conditions and is beneficial to improving the tensile strength of resulting carbon fiber. The composition of P(AN-co-MHI) was controlled by the ratio of DMSO/deionized water in the mixed solvents, it is attributed to the changes of AN/MHI ratio taking part in the polymerization reactions, which is caused by the different solubility of AN in the mixed solvents. From elemental analysis and FTIR studies, it can be found out that the content of MHI in P(AN-co-MHI) copolymer becomes larger with the increase of DMSO content in the mixed solvents. The FTIR, XRD and DSC results show that the stabilization of P(AN-co-MHI) copolymer was significantly improved by MHI compared with PAN homopolymer and poly (acrlonitrile-methyl acrylate-acrylic acid) terpolymer, such as larger extent of stabilization, lower initiation temperature and smaller Ea of cyclization, which is beneficial to preparing high performance carbon fiber.

To replace ternary polymer with binary polymer, a novel bifunctional comonomer β-methylhydrogen itaconate (MHI) was synthesized to prepare poly(acrylonitrile-co-β-methylhydrogen itaconate) [P(AN-co-MHI)] copolymer used for carbon fiber precursor. The structural evolution and stabilization mechanism of P(AN-co-MHI) and polyacrylonitrile (PAN) during stabilization were studied by Fourier transform infrared spectroscopy, x-ray diffraction, differential scanning calorimetry, thermogravimetry, and kinetic investigation. The activation energy (Ea) of the stabilization reactions were calculated by Kissinger method and Ozawa method. The results show that the P(AN-co-MHI) exhibits a lower stabilization temperature than terpolymers containing similar chemistry component and a significantly improved stabilization performance compared with PAN homopolymer, such as lower cyclization temperature, lower Ea (85.36 kJ/mol), and larger extent of stabilization under the same condition, which is mainly attributed to the initiation of MHI comonomer through an ionic cyclization mechanism. The dehydrogenation of P(AN-co-MHI) is also promoted by the incorporation of comonomer MHI into PAN chains. Simultaneously, the rheological analysis shows that P(AN-co-MHI) possesses better spinnability than PAN, which is beneficial for preparation of high performance carbon fiber.

The nano-sized copper sulfides (CuS) with different morphologies were prepared by hydrothermal method without any surfactant or template. The morphology and structure of CuS were characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) and ultraviolet-visible (UV-vis) absorption spectroscopy. FESEM results show that four morphologies of CuS (flower-like nanospheres, cross-linked nanodisks, cross-linked nanoplates and nanosheets) were prepared simply by changing the hydrothermal solvent. According to the XPS, XRD and HRTEM results the synthesized nano-sized structures are highly crystallized pure hexagonal covellite CuS. UV-vis spectra results show intense absorption peaks in the visible region, confirming that the resultant CuS has potential application in the field of solar cells. The catalytic activities of resultant CuS on model pollutant methylene blue (MB) in the dark were also investigated in detail. The small and flat crystallites show rapid degradation rate on MB, which is attributed to the numerous active sites on their large specific surface area. The as synthesized CuS nanosheets took the shortest time (only 15 minutes) to degrade MB completely compared with the other nanostructural CuS in this work as well as previously reported ones. Total organic carbon (TOC) removal of the samples approved mineralization of the MB pollutant. Thus, CuS is an excellent catalyst for degrading organic pollutants, which doesn't require light energy for its catalytic activities.

The utility of this method is demonstrated in the synthesis of β-secretase 1 inhibitor (VIIa).

In order to prepare high performance carbon fiber precursor, firstly a bifunctional comonomer β-methylhydrogen itaconate was synthesized to prepare poly (acrylonitrile-co-β-methylhydrogen itaconate) [P (AN-co-MHI)] copolymer, which was used as carbon fiber precursor instead of poly (acrylonitrile-acrylic acid-methyl acrylate) [P (AN-AA-MA)] terpolymer; secondly a two-step method containing aqueous suspension polymerization and solution polymerization was used to prepare carbon fiber precursor. The structural evolution and stabilization mechanism of P (AN-co-MHI) and [P (AN-AA-MA)]-based carbon fiber precursor were studied by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetry; the spinnability and tensile strength were investigated by thermo scientific HAAKE CaBER1and XQ-1 tensile tester, respectively. The results show that the P (AN-co-MHI)-based carbon fiber precursor exhibits much better stabilization than that based on P (AN-AA-MA), such as lower initiation temperature, broadened heat release and smaller Ea of cyclization, which is mainly attributed to the initiation of MHI through an ionic mechanism. The carbon fiber precursor prepared by two-step method possesses better spinnability than that prepared by solution polymerization. Furthermore, the tensile strength of carbon fiber precursor prepared by two-step method has been improved by about two times, which is beneficial to preparing high performance carbon fiber.

In order to replace terpolymer with bipolymer, a novel bifunctional comonomer 3-ammoniumcarboxylate-3-butenoic acid methyl ester (ACBM) containing both ester and ammonium carboxylate groups was synthesized to prepare poly(acrylonitrile-co-3-ammoniumcarboxylate-3-butenoic acid methyl ester) [P(AN-co-ACBM)] bipolymer used as carbon fiber precursor. The stabilization and spinnability of P(AN-co-ACBM) and poly(acrylonitrile-methyl acrylate-ammonium acrylate) [P(AN-MA-AA)] was studied by fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetry and rheological analysis. Two parameters $$ {E}_s={A}_{1612c{m}^{-1}}/{A}_{2244c{m}^{-1}} $$ and SI = (I 0 − I S )/I 0 were defined to evaluate the extent of stabilization, and the activation energy (E a) of the stabilization reactions were calculated by Kissinger method and Ozawa method. The results show that the stabilization of P(AN-co-ACBM) has been remarkably improved by ACBM compared with P(AN-MA-AA) terpolymer, such as lower initiation temperature, broadened exothermic peak, larger extent of stabilization and smaller Ea of cyclization. Moreover, the spinnability of P(AN-co-ACBM) is improved by ACBM due to the lubrication of ester groups in ACBM compared with polyacrylonitrile homopolymer. This study clearly shows that P(AN-co-ACBM) bipolymer is a better material used as carbon fiber precursor than P(AN-MA-AA) terpolymer.

In order to improve the pre-oxidation and spinnability of polyacrylonitrile (PAN) at the same time, a bifunctional comonomer 3-ammoniumcarboxylate-butenoic acid-methyl ester (ACBM) was designed and synthesized to prepare poly(acrylonitrile-co-3-ammoniumcarboxylate-butenoic acid-methyl ester) [P(AN-co-ACBM)] copolymers used as carbon fiber precursor instead of acrylonitrile terpolymers. The P(AN-co-ACBM) copolymers with different compositions were characterized by elemental analysis, Fourier transform infrared spectroscopy, X-ray diffraction and differential scanning calorimetry. Both the conversion of polymerization and molecular weight decease with the increasing of ACBM content in P(AN-co-ACBM) due to the larger molecular volume of ACBM than AN, and the monomer reactivity ratios study shows that ACBM possesses higher reactivity than AN. Two parameters $$ {E}_s={A}_{1619c{m}^{-1}}/{A}_{2244c{m}^{-1}} $$ and SI = (I 0 − I S )/I 0 were defined to evaluate the extent of pre-oxidation, and the activation energy (E a) of the cyclization was calculated by Kissinger and Ozawa methods. The results show that P(AN-co-ACBM) copolymers exhibit significantly improved pre-oxidation characteristics than PAN homopolymer, such as lower initiation temperature, larger extent of pre-oxidation and smaller E a of cyclization, which is attributed to the initiation of ACBM through ionic mechanism. In addition, the rheological analysis shows that the spinnability of P(AN-co-ACBM) copolymer is better that that of PAN, which is beneficial to preparing high performance carbon fiber.