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Background: 4,4′-isopropylidenediphenol (BPA) hydrogenated to 2,2-bis(4-hydroxycyclohexyl) propane (HBPA) is a simple way to reduce its toxicity and environmental impact. In addition, the higher trans/trans HBPA moiety in polymer will has better mechanical properties. Therefore, how to prepare trans/trans HBPA via hydrogenation is an important issue. Method: One-dimensional nickel-palladium catalyst was successfully synthesized via reduction by an external magnetic field. The high ratio of trans/trans HBPA was characterized by FTIR, GC/MS, and NMR, respectively. The adsorption behavior of BPA and its half-hydrogenated intermediates was studied by Material Studio software. Significant findings: The pd nanoparticles immobilized on the magnetization of 1-D Ni catalyst with high amount of Ni(111) plane is the novelty of this research. The conversion of BPA was high to 100% and the ratio of trans/trans HBPA was over than 75% at 180 °C and 70 kgf/cm2 in isopropanol medium. The trans/trans ratio of HBPA was slightly increasing as increasing hydrogen pressure and decreasing reaction temperature. Reaction intermediate was selected with the aid of molecular simulation. Moreover, the reaction path of BPA hydrogenated by one-dimensional nickel-palladium catalyst was proposed that BPA was firstly hydrogenated to tetrahydro intermediate and followed roll-over mechanism to obtain trans/trans HBPA product.

Background Effective high-throughput strategies to prepare nanostructured electrodes for glucose sensing remain significant interest for many applications. In this study, acicular nickel was immobilized on carbon nanofibers (CNFs) via electroless plating under a magnetic field to form CNFs-Ni, and its application as an electrode in amperometric non-enzymatic glucose sensing was investigated. Methods Polyacrylonitrile (PAN) nanofibers (NFs) were fabricated by centrifuged-electrospinning, in which the combination of electrostatic and centrifugal forces produces a strong stretching force. PAN polymer chains were aligned parallel to the axis of the NFs, thereby stretching the dispersed PAN droplets into thin and molecularly orientated NFs. The PAN NFs were then subjected to stabilization followed by carbonization at 1200, 1300, 1400, or 1500 °C to produce PAN CNFs. The characteristics of the CNFs were confirmed by scanning electron microscopy (SEM), electron spectroscopy for chemical analysis, Raman spectroscopy, and four-point probe analysis. Additionally, the CNFs coated with acicular nickel (CNFs-Ni) were analyzed by SEM, X-ray diffraction, and high-resolution transmission electron microscopy. Significant Findings Under the optimal conditions (CNFs1400-Ni), the glucose sensor showed a high sensitivity (7404 μA mM−1 cm−2) with a linear range from 2.1 × 10−2 to 6.0 × 10−1 mM (R2 = 0.993) and fast response (10 s).

Background The power-to-gas (PtG) method has significant potential as a strategy for storing excess renewable energy in the form of synthetic natural gas. PtG involves the hydrogenation of CO2 to CH4 from H2 obtained from renewable energy. Methods In this study, Ni–Fe catalysts with different Ni/Fe ratios were prepared for high-efficiency CO2 methanation using chemical reduction with an external magnetic field. The Ni–Fe catalysts were characterized by XRD, inductively coupled plasma, and SEM-EDS measurements, and their performance and chemical properties were measured by H2 temperature programmed reduction experiments. Significant findings The catalyst with the best performance for CO2 methanation had a ratio of Ni to Fe of 8/2 (Ni8Fe2). The Ni8Fe2 catalyst could convert over 80% of CO2 to methane at 150 °C. In addition, the CH4 selectivity of CO2 methanation was 95% when the reaction conditions were controlled at H2/CO2 = 4 and GHSV ∼1000 h−1. The low cost and simple preparation of these Ni–Fe catalysts have high potential for future commercialization.

Background Only a small amount of polyaniline will possibly form passive layers on the surface of the metallic substrate in well-dispersed epoxy coatings. Therefore, introducing the majority of polyaniline additive to the surface of steel can optimize the anti-corrosion performance. Methods In this study, novel magnetic CoFe2O4-polyaniline nanocomposite additives are synthesized via oleic acid as a dispersion agent. The morphology of CoFe2O4-oleic acid-polyaniline (CoFe2O4-OA-PANI) is characterized by TEM, SEM-EDS, FTIR spectroscopy, and X-ray diffraction, respectively. Significant findings The corrosion protective efficiency of CoFe2O4-OA-PANI on carbon steel is 2.46 times higher than that of pristine PANI after 30 days of immersion in 0.1 M HCl solution experiment. The 3D-optical microscopy (3D-OM) images show that the carbon steel substrate with the CoFe2O4-OA-PANI/epoxy coating has the least corrosion depth among others because a denser protective passive layer is formed well on the contact surface between CoFe2O4-OA-PANI/epoxy coating and carbon steel. Finally, the results of 100-day immersion electrochemical impedance spectroscopy under acidic (9.47 × 1010 Ω) or saline (4.81 × 1010 Ω) conditions reveal that the CoFe2O4-OA-PANI within the epoxy coating has the highest coating resistance, indicating that the CoFe2O4-OA-PANI is a high-efficiency and highly promising anticorrosive agent for commercial applications.

The effect of the use of sandwich-like polyaniline (S-PANI) nanocomposites in CO2 gas-separation membranes was investigated. S-PANI nanocomposites were synthesized via a two-step dispersion polymerization method. The first step was to manufacture a leaf-like polyaniline (L-PANI), which was used in the next step as a 2D template to synthesize the S-PANI. SEM images show that a three-layer sandwich-like structure of the S-PANI was successfully synthesized. ATR-FTIR measurements revealed that the S-PANI has a structure with conductive PANI layers on both sides of the L-PANI template. Furthermore, the N2 and CO2 adsorption isotherms illustrate that S-PANI is much more attractive to CO2 than N2 because of the amine functional groups of S-PANI. Hence, the CO2/N2 separation performance of the ethylene vinyl acetate (EVA) copolymer membrane was successfully enhanced by the addition of the S-PANI nanocomposite. The CO2/N2 selectivity of the membrane increased from 6.8 to 32.5 with a 3-wt% loading of S-PANI within the EVA matrix. The results show that 2D S-PANI could feasibly be used for CO2 gas membrane separation.

Aliphatic polycarbonate-based polyurethanes were successfully synthesized using two aliphatic polycarbonate polyols and hexamethylene diisocyanate (HDI) with 1,4-butanediol (1,4-BD) as the chain extender. One of the aliphatic polycarbonate polyols, named PBC-diol, was prepared from dimethyl carbonate (DMC) and 1,4-BD, while the other, named PCHC-diol, was derived by reacting DMC with 1,4-cyclohexanedimethanol (CHDM). The results of the thermogravimetric analysis (TGA) indicated that the cyclic structure improved the thermal stability of the polyurethanes. In addition, the differential scanning calorimetry (DSC) curves showed that the cyclic structure increased the glass transition temperature (Tg) of the polyurethanes but slowed their crystallization. Furthermore, the mechanical properties of the polyurethanes with different cyclic structure contents were analyzed using Instron. Although the elongation at break decreased, the tensile strength increased from 32.6 to 844.0 MPa when the PBC-diol was replaced with PCHC-diol in the polyurethanes. Finally, Fourier transform infrared (FTIR) analysis was conducted to investigate the formation of hydrogen bonds. The relationship between the hydrogen bonds and cyclic structure content was also shown in this study. A series of aliphatic polycarbonate-based polyurethanes with different content of cyclic structure was synthesized. There were more hydrogen bonds between soft and hard segments formed as the content of cyclic units increased. The mechanical and thermal properties of the environment-friendly polycarbonate-based polyurethanes can be enhanced and controlled by varying the content of the cycloaliphatic structures. These polyurethanes can be considered as high potential materials that can be used in different applications in the future.

Nickle catalysts with acicular nanostructures are prepared by chemical reduction under different external magnetic fields. The characteristics reveal by XRD and HR-TEM illustrated that the growth of the Ni (111) plane is enhanced with the increasing in external magnetic field intensity. The shape of the Ni catalyst changes from particle to wire when the external magnetic field was greater than 1000 G. The TOF of catalysts increases linearly as the ratio of the (111)/(200) crystal planes increases, according to TPR and CO chemisorption experiments. The Ni catalyst prepared under 500 G external magnetic field shows good catalytic performance for CO2 methanation below 200 °C. Up to 99% conversion and CH4 selectivity of CO2 is obtained at 200 °C with H2/CO2 = 4.5 and GHSV ~ 1,000 h−1. Furthermore, the catalysts remine unchanged after 120 h at 180 °C. The activation energy of CO2 methanation on Ni catalysts is 84.7 kJ/mol.

In this study, novel hydrogenation catalysts consisting of palladium (Pd) immobilized in a nickel wire (Pd/Niw) were prepared via the application of an external electromagnetic field. Scanning electron microscopy were used to detect the characteristics and morphology of the catalysts, respectively. The Pd content of the Pd/Niw was found to range from 13 wt.% to 15 wt.% via inductively coupled plasma-atomic emission spectroscopy. The size of the Pd particles in Pd/Niw was determined to be in the range 20−100 nm via high-resolution transmission electron microscopy. Furthermore, the Pd/Niw acted as a catalyst for the hydrogenation of bis(2-ethylhexyl)phthalate (DEHP), with nearly 100% conversion of DEHP being obtained at 180 °C and 1000 psi. The reduction temperatures of the novel Niw support were 266 °C and 296 °C according to TPR measurements. The activation energy for the Pd/Niw-catalyzed hydrogenation of DEHP was calculated to be 35 kJ/mol. This high-performance hydrogenation catalyst has potential for commercialization due its easy production and low cost.

The novel technique of centrifuged-electrospinning is employed to fabricate immiscible polyacrylonitrile (PAN)/polymethyl methacrylate (PMMA) polymer fibers, followed by carbonization to form ultra-thin carbon nanofibers (UT-CNF) with 28 ± 11 nm diameters. An additional centrifugal force provides a strong stretching force to stretch the dispersed droplets (PAN) into ultra-thin nanofibers, as confirmed by electron microscopy. This structure presents good electrochemical properties compared to electrospun carbon nanofibers with 126 ± 16 nm diameters. Electrochemical impedance spectroscopy analysis shows enhanced efficient surface areas, which accumulate ions more quickly, resulting in a decrease in the charge distribution and ion diffusion resistance because the reduction in diameter provides a short pore length and large outer surface. Applied to a supercapacitor, galvanostatic charge/discharge analysis gives a maximum specific capacitance of 243 F/g at 1 A/g and capacitance retention of 77.1% at a charge/discharge rate of 100 A/g for UT-CNF. This result is significantly higher than that of traditional electrospun carbon nanofibers.

Hydrogenated bisphenol-A polycarbonate (PHBPA) was successfully synthesized from dimethyl carbonate (DMC) and hydrogenated bisphenol-A (HBPA) by the method of two-step polycondensation. The chemical structure and the molecular weight of PHBPA was identified by 1H-NMR spectra and gel permeation chromatography (GPC), respectively. In order to analyze the thermal degradation mechanism of PHBPA, a non-isothermal pyrolysis process was conducted and the violate products were detected using Fourier-transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC-MS). There were some reactions occurred during the pyrolysis including decarboxylation, disproportionation of the C–H transfer and β–H transfer, and the Fries rearrangement. In addition, the well-known Flynne–Walle–Ozawa (FWO) and Coats–Redfern kinetic analysis methods were used to calculate the values of activation energy and pre-exponential factors. Furthermore, isothermal pyrolysis experiments were performed and revealed that the reaction of decarboxylation occurred at 225 °C. This decarboxylation suggests that the molecular chain of PHBPA does not easily grow to a high-molecular-weight polymer.

Silver nanoparticles on the surface of carbon nanotubes functionalized with maleic anhydride through plasma-induced grafting process, named CNTs-MA-Ag, were synthesized. Effects of CNTs-MA-Ag as conductive additives on the performance of LiFePO4 polyanion-based lithium-ion batteries was studied. X-ray diffraction analysis, transmission electron microscopy, and UV-vis spectroscopy were used to characterize Ag nanoparticles on the surface of CNTs-MA-Ag. Morphology of LiFePO4/CNTs-MA-Ag electrode was observed via scanning electronic microscopy. Electrochemical impedance spectroscopy analysis was conducted to acquire the charge transfer resistance of composite cathode. The specific capacity, cyclic stability and rate performance of LiFePO4/CNTs-MA-Ag coin cells were evaluated through galvanostatic charge/discharge process. LiFePO4/CNTs-MA-Ag (5 wt%) coin cells have specific capacity of 148 mAhg−1 at 0.1C with a capacity retention ratio of 98.6% after 100 cycles, and rate capacity of 113.6 and 77.8 mAhg−1 at 1C and 2C, respectively. Taken together, CNTs-MA-Ag can serve as excellent conductive additives to improve performance of polyanion-based LIBs.

The application of LiFePO4 in high power battery is limited by its low conductivity. MWCNTs as conductive additives were functionalized with maleic anhydride (MA) using the plasma-induced grafting technique. A series of LiFePO4/MWCNTs-MA composite electrodes with 1.7 wt%, 2.7 wt%, 4.7 wt%, and 9.7 wt% of MWCNTs-MA were fabricated to improve conductivity and to investigate the effects of MWCNTs-MA on LiFePO4 electrode performance. X-ray diffraction analysis of LiFePO4/MWCNTs-MA cathodes showed that crystallinity and lattice spacing of LiFePO4 were not altered by incorporation of MWCNTs-MA. Field-emission scanning electronic microscopy showed that 4.7 wt% MWCNTs-MA dispersed well in LiFePO4 particle matrix. Electrochemical impedance spectroscopy showed that charge transfer resistance was decreased by increased amount of MWCNTs-MA. The specific capacity, cyclic stability, and rate performance of LiFePO4 coin cells were enhanced by increased amount of MWCNTs-MA, and reaching optimal performance at 4.7 wt%. The LiFePO4/MWCNTs-MA (4.7 wt%) battery had rate capacity of 114 mAh g−1 at 1 C with a capacity retention ratio of 75.6% after 200 cycles.

The effects of MWCNT incorporation into non-vacuum chalcopyrite nanoparticle deposition solar cells were investigated in this study. To improve MWCNT dispersion within CuIn(S, Se) 2 nanoparticle ink, MWCNT were grafted with maleic anhydride (MA) via plasma treatment. The functional groups on the surface of MWCNT were characterized by X-ray photoelectron spectroscopy. The grafting level of MA on MWCNT was 18.6 wt%. A series of CuIn(S, Se) 2 nanoparticle solar cells with various weight ratios (wt%) of MWCNT-MA were fabricated. The structure of grounded CuIn(S, Se) 2 nanoparticles was verified by transmission electron microscopy and X-ray diffraction analysis. The band gap energy of CuIn(S, Se) 2 nanoparticles was obtained by UV–vis-NIR spectrophotometer. Scanning electronic microscopy showed that MWCNT–MA at ≤0.5 wt% dispersed well within CuIn(S, Se) 2 nanoparticles. At 0.33 wt%, MWCNT-MA facilitated 15% increase in conversion efficiency of solution-based CuIn(S, Se) 2 nanoparticle solar cells by increasing carrier transfer efficiency, and thus, increasing current density J sc .

The different amount of hydrophilic hydroxyl group, including 3, 5, 7 and 10 wt.% copoly (styrene-co - divinyl benzene – co - 2-hydroxylethylenemethacrylate) (poly (St-co-DVB- co -HEMA) s) nanoparticles were synthesized via microemulsion polymerization in the present paper. The average size of the poly (St-co-DVB-co-HEMA) s was ca. 44 nm after zetasizer (DLS) measurement and SEM observation. The characteristic peaks at 3200 ~3600 cm-1 in FTIR was assigned at hydroxyl group of HEMA unit. The NBR/poly (St-co-DVB-co-HEMA) s composites films with 250 μm thickness were prepared simply via latex mixing and followed by spinning coating. The mechanical properties of the poly (St-co-DVB-co-HEMA) s/rubber nanocomposites, including the tensile strength, modulus and elongation, were increased with that of increasing of poly (St-co-DVB-co-HEMA) s adding. In addition, as the poly (St-co-DVB-co-HEMA) s nanoparticles carried out with constant St/HEMA molar ratio of 97:3 and the DVB content in 10 wt.%, the elongation at break that up to more than 3500% and the ultimate stress increased from 0.2 MPa to 0.6 MPa. The poly (St-co-DVB-co-HEMA) s nanoparticles prepared by emulsion polymerization could be successfully enhanced the mechanical properties of rubber latex.

Wastewater treatment with bioelectrical generation is an attractive feature with microbial fuel cells. The chitosan/biodegradable copolymer proton exchange membrane was used to assess its performance with brewery wastewater in a dual chambered microbial fuel cell. The biodegradable copolymer was made by thermal condensation of malic acid and citric acid in 3:1 ratio and then blended with chitosan to form a membrane via solution casting and solvent evaporation techniques. The performance of the chitosan/biodegradable copolymer membrane was evaluated in bioelectricity production with brewery effluent as an anolyte in a carbon electrode microbial fuel cell. Additionally, the competence of the prepared blend proton exchange membrane is compared with the commercial Nafion 117 membrane and Agar salt bridge in separate microbial fuel cell units with the same effluent and electrodes. At neutral pH, the effect of adding metabolites such as glucose and acetate to the anolyte was also investigated. The maximum current density and power density generated with chitosan/biodegradable copolymer membrane was 111.94 mA m−2 and 3022.39 mW m−2, respectively, whereas the Nafion 117 membrane had a maximum current density of 120.23 mA m−2 and power density of 3486.73 mW m−2.

Several wearable devices have already been commercialized and are likely to open up a new life pattern for consumers. However, the limited energy capacity and lifetime have made batteries the bottleneck in wearable technology. Thus, there have been growing efforts in the area of self-powered wearables that harvest ambient mechanical energy directly from surroundings. Herein, we demonstrate a woven triboelectric nanogenerator (WTENG) utilizing electrospun Polyvinylidene fluoride (PVDF) nanofibers and commercial nylon cloth to effectively harvest mechanical energy from human motion. The PVDF nanofibers were fabricated using a highly scalable multi-nozzle far-field centrifugal electrospinning protocol. We have also doped the PVDF nanofibers with small amounts of multi-walled carbon nanotubes (MWCNT) to improve their triboelectric performance by facilitating the growth of crystalline &beta, phase with a high net dipole moment that results in enhanced surface charge density during contact electrification. The electrical output of the WTENG was characterized under a range of applied forces and frequencies. The WTENG can be triggered by various free-standing triboelectric layers and reaches a high output voltage and current of about 14 V and 0.7 &micro, A, respectively, for the size dimensions 6 &times, 6 cm. To demonstrate the potential applications and feasibility for harvesting energy from human motion, we have integrated the WTENG into human clothing and as a floor mat (or potential energy generating shoe). The proposed triboelectric nanogenerator (TENG) shows promise for a range of power generation applications and self-powered wearable devices.

The bulk copolymerization of methyl methacrylate (MMA) with vinyl monomers initiated by e-caprolactam (CL) and n-dodecyl mercaptan (RSH) was investigated. Acrylonitrile (AN) and vinyl acetate (VAc) were used to copolymerize with MMA at 90 °C in the presence of CL and RSH, respectively. As evidenced by first-order kinetics of polymerization, linear increase of molecular weights with monomer conversions, and relatively low PDI values within a range of 1.3 to 1.6, both the copolymerization reactions exhibited living characteristics. Dependences of the copolymerization on the monomer feed ratio was also studied. An increase in the feed ratio of MMA induced an increased rate of copolymerization. In contrast, an increase in the initial loading of vinyl monomer leaded to the decrease in rate of copolymerization. The reactivity ratios of each pair of comonomers were also assessed using Fineman-Ross (FR) method. The results showed that the CL has an important influence on the kinetics of copolymerization, which caused the copolymerization parameters different from the most previously reported values.

The functional polymer (PMA-co-MAA) latex microspheres were used as a core template to prepare magnetic hollow spheres consisting of CoFe2O4/SiO2 composites. The spinel type crystal structure of CoFe2O4 ferrite is formed under annealing, whereas the polymer cores are completely removed after annealing at 450 °C. Magnetic and Mossbauer spectroscopy measurements reveal very interesting magnetic properties of the CoFe2O4/SiO2 hollow spheres strongly dependent on the particle size which can be tuned by the annealing temperature. In the ground state of low temperatures, the CoFe2O4 nanoparticles are in antiferromagnetic state due to the canted magnetic structure. Under heating in the applied field, the magnetic structure gradually transforms from canted to collinear, which increases the magnetization. The Mossbauer data revealed that the small size CoFe2O4/SiO2 particles (2.2–4.3 nm) do not show superparamagnetic behavior but transit from the magnetic to the paramagnetic state by a jump-like magnetic transition of the first order This effect is a specific property of the magnetic nanoparticles isolated by inert material, and can be initiated by internal pressure creating at the particle surface. The suggested method of synthesis can be modified with various bio-ligands on the silane surface, and such materials can find many applications in diagnostics and bio-separation.

Polyaniline is grafted onto the surface of high conductivity carbon nanotube-embedded carbon nanofibers (PANi-P-1.0) via plasma modification to fabricate an electrode for a high performance supercapacitor. The structure and morphology of polyaniline graft onto the carbon nanofiber (CNF) are confirmed by Raman, X-ray photoelectron spectroscopy, electron microscopy and transmission electron microscopy. The emeraldine base form of nanorod-polyaniline is well-distributed on the surface of the CNF. The PANi-P-1.0 has a high specific capacitance of 606 Fg−1. From the result of the electrochemical properties, the high capacitance is contributed by the electric double layer capacitance of the high conductivity CNF and the pseudocapacitance of the grafting polyaniline. In addition, compared to polyaniline coated on the surface of the CNF, the electrochemical properties of the PANi-P-1.0 are improved by reducing the charge transfer resistance (Rct) from 13.54 to 3.87 Ω, the Warburg coefficient from 101.39 to 47.96 Ωs−1/2 and the relaxation time constant from 0.794 to 0.194 s due to the covalent bond between the polyaniline and CNF. The PANi-P-1.0 also show excellent cycling stability after 1,000 cycles of galvanostatic charge and discharge because the free space around the grafting polyaniline allows volumetric change.

A peculiar living free radical polymerization process for the preparation of poly(methyl methacrylate)-b-poly(isoprene)-b-poly(methyl methacrylate) (MIM) triblock copolymers using anionic living polymerization (ALP) combined with mercaptan/e-caprolactam living polymerization (MLP) is developed. Polyisoprene (PI) is first synthesized by ALP using a difunctional t-BuLi initiator with tetrahydrofuran as the polar regulator. Then, a PI with a controlled isomeric unit is end-group functionalized with mercaptans to form an α,ω-bismercaptan-functionalized PI precursor polymer, which is characterized by MALDI-TOF mass spectrometry, after which a thiolamide-structured MIM is formed by MLP at 90 °C. Living characteristics are confirmed by GPC, which reveals that MIMs with Mn values of 42.1–81.3 kDa are prepared. The polymers are also characterized by NMR spectroscopy, and gradient polymer elution chromatography. In addition, two Tgs are observed for each polymer by DSC: between −57.2 and 10.4 °C, and 99.4 and 119.8 °C, which correspond to the separated microphases within each MIM.

A series of aliphatic oxalate-polycarbonate polyols (AOPC) was synthesized from dimethyl carbonate, 1,6-hexanediol, and diethyl oxalate, made from oxalic acid that is a kind of bio-based material, via melting polycondensation. The aliphatic polycarbonate-based polyurethanes with oxalate units (AOPCUs) were successfully prepared using the AOPCs and hexamethylene diisocyanate (HDI) with 1,4-butanediol (1,4-BD) as the chain extender. The results of the 1H NMR analysis showed that the Mn of AOPCs was approximately 2900. Whereas, the Mw of the AOPCUs was ca. 48,200–53,000 from the gel permeation chromatography (GPC) measurement. The oxalate unit effectively impeded the crystallization of the AOPCUs as shown in the Differential scanning calorimetry (DSC) analysis. Based on the stress-strain curves, the AOPCUs with 10 M ratio of oxalate unit had best strength and elongation at break; however, their Young's modulus decreased from 130 MPa to 26 MPa. In addition, the biodegradation of the AOPCUs was studied using the fungi, Aspergillus sp. and Fusarium sp. The more oxalate units in the AOPCUs, the better biodegradability they presented after the 84-day degradation test. The characteristics of the biodegradation analysis for the AOPCUs presented the bulk erosion, and the oxalate unit played an important role in their biodegradability.

Polypropylene-graft-maleic anhydride (PP-g-MAH) ionically modified with zinc(II) (PP-g-MAHZn) in varying amounts of ionic associations were prepared via melt reaction. Absorption bands in FTIR-ATR and shifted binding energy in X-ray photoelectron spectroscopy showed the formation of zinc carboxylates in PP-g-MAHZn. Decreased crystallinity, gradually increased viscosities, and storage modulus with the increment of zinc carboxylates in the PP-g-MAHZn were investigated by thermal and rheological analysis, which were attributed to the restriction of chain mobility via ionic interactions between polymer chains and aggregations of ionic domains. Furthermore, PP-g-MAHZn was introduced to polypropylene as an additive to promote foamability, and the PP/PP-g-MAHZn blends displayed higher viscosities and storage modulus compared with pristine PP in rheological measurements. In addition, the PP/PP-g-MAHZn blends were foamed by supercritical CO2 and cryogenically fractured surfaces were observed by scanning electron microscope. PP/PP-g-MAHZn foams presented high closed-cell content, uniformity of cells, and increasing cell density owing to the combined effects of rheological properties, while maintaining the cell structures and good dispersion of the PP-g-MAHZn as nucleating sites. These results reveal that PP-g-MAHZn is a suitable additive to produce high melt strength PP for foam production.

Aliphatic polycarbonate (PDCM) was synthesized from dimethyl carbonate and 1,4-cyclohexanedimethanol via melting polymerization in this study. The molecular weight of PDCM was determined by gel permeation chromatography (GPC) to be ca. 49,900. The crystallization behavior and crystallinity of polyethylene terephthalate (PET) were significantly modified by adding 0.3–5.0 wt% PDCM, which was confirmed by differential scanning calorimetry (DSC), photomicrography with a heating stage and SAXS analysis. In nonisothermal crystallization kinetics analysis, the reciprocal of half-time crystallization (i.e., G parameter) for the 1.0 wt% PDCM/PET blends is 3.5 times greater than that of pristine PET at a cooling rate of 10 °C/min. Observation via polarized optical microscopy showed that the spherulites size of PET was condensed by PDCM. In addition, the fold surface energy (σe) decreased with the presence of PDCM. According to the results of dynamic mechanical analysis (DMA) examination, the mechanical strength of 1.0 wt% PDCM/PET thin film was enhanced as the transparency still maintained above 85%, which illustrated the transparent thin film has better thermal stability and has high potential to be used such as in the electronic appliances.

Maleic anhydride grafted onto atactic polypropylene (aPP-g-MAH) using a solution grafting reaction with e-caprolactam promoter was investigated in this study. FTIR-ATR and elemental analysis (EA) measurements showed that the optimal degree of grafting (DG) of aPP-g-MAH could be achieved at a 5.03 wt% when e-caprolactam was added as the radical protecting agent. aPP-g-MAH was then introduced to PP and PP/Nylon 6 (PP/Ny6) as a nucleation and compatibility agent, respectively. The DSC curve of the PP/aPP-g-MAH blend showed that the crystallization temperature of the blend was increased to 115.3 °C, higher than that of pristine PP. In addition, POM observations demonstrated that the size of the spherulites present in pristine PP shrank obviously. Moreover, the dynamic temperature variations in the POM observations revealed that the initial crystallization temperature of PP/aPP-g-MAH was much higher than that of pristine PP. The results indicate that the aPP-g-MAH additive was an excellent nucleating agent for the PP materials. When aPP-g-MAH was added as a compatibility agent for PP/Ny6 blending, the cryogenically fractured surface of the PP/Ny6/aPP-g-MAH (5 wt%) blend presented good compatibility between PP and the Ny6 domains. The crystallization temperatures of PP/Ny6 blends with 10–50 wt% Ny6 were higher than that of pure PP, and the blends with aPP-g-MAH had much higher of that. These findings reveal that aPP-g-MAH is a good nucleation and compatibility agent in PP/Ny6 blends.

Triblock copolymers poly(styrene)-block-poly(isoprene)-block-poly(styrene) (PS-b-PI-b-PS, SIS) and poly(isoprene)-block-poly(styrene)-block-poly(isoprene) (PI-b-PS-b-PI, ISI) with different vinyl structure contents were successfully synthesized by anionic polymerization using a difunctional t-BuLi initiator. The difunctional t-BuLi initiator was prepared from tert-butyllithium (t-BuLi) and 1,3-diisopropenylbenzene, and characterized by 1H NMR, 13C NMR, DEPT135, 7Li NMR, and GC–MS analysis. According to the results of 1H NMR, 13C NMR, and 2D HSQC analysis, the contents of 1,2- and 3,4-addition (vinyl group) structures for PI in SIS and ISI were in the range of 3.7%–94.6%, and depended on the reaction temperature and amount of tetrahydrofuran (THF) added. The Mn and PDI of SIS and ISI obtained by GPC were in the ranges of 13,400–281,000 Da and 1.09–1.24, respectively. The presence of two glass transition temperatures (Tg) on the DSC curve indicated microphase separation of the PI and PS domains. The low Tg was attributed to the PI domain, which was correlated with the vinyl group content in the block copolymer. For vinyl group contents of 6.9% and 94.6% in the SIS triblock copolymer, and 6.6% and 94.2% in the ISI triblock copolymer, the corresponding Tg values of the PI block were −64 °C and 12 °C, and −62 °C and 17 °C, respectively.

In this study, we have fabricated a simple disposable electrochemical immunosensor for the point of care testing of microalbuminuria, a well-known clinical biomarker for the onset of chronic kidney disease. The immunosensor is fabricated by screen-printing carbon interdigitated microelectrodes on a flexible plastic substrate and utilizes electrochemical impedance spectroscopy to enable direct and label free immunosensing by analyzing interfacial changes on the electrode surface. To improve conductivity and biocompatibility of the screen-printed electrodes, we have modified it with gold nanoparticles, which are electrodeposited using linear sweep voltammetry. To enable efficient immobilization of HSA antibodies, we have developed novel PS/Ag/ab-HSA nanoprobes (polystyrene nanoparticle core with silver nanoshells covalently conjugated to HSA antibodies), and these nanoprobes are trapped on the electrode surface using dielectrophoresis. Each immunosensor has two sensing sites corresponding to test and control to improve specificity by performing differential analysis. Immunosensing results show that the normalized impedance response is linearly dependent on albumin concentration in the clinically relevant range with good repeatability. We have also developed a portable impedance readout module that can analyze the data obtained from the immunosensor and transmit it wirelessly for cloud computing. Consequently, the developed immunosensing platform can be extended to the detection of a range of immunoreactions and shows promise for point of diagnosis and public healthcare monitoring.

Shell crosslinked nanoencapsulate were prepared via crosslinking reaction between double hydrophilic grafted copolymers poly(N-isopropyl acrylamide)-co-poly(L-lysine) (PNIPAm-co-PLLys) and natural crosslinking agent genipin. These shell crosslinked nanoencapsulate possess spherical structures and the hydrodynamic radiuses are about 18.5 nm to 37.7 nm. Drug-loaded shell crosslinked nanoencapsulate were applied as drug carriers. Model drug methotrexate (MTX) were loaded into polymeric nanoencapsulate with different loading ratios (polymer / MTX = 10 / 0.5 and 10 / 1.0), then crosslinking agent genipin was added into micelle solution to form drug-loaded shell crosslinked nanoencapsulate. Entrapment efficiency and drug loading content of the drug-loaded shell crosslinked nanoencapsulate are about 12.66 wt% to 20.1 wt% and 0.84 wt% to 1.28 wt%, respectively. In-vitro drug release experiments of drug-loaded shell crosslinked nanoencapsulate were carried out in pH 7.4 phosphate buffer solution at 37 °C. All of these samples possess burst release in initial 8 h, and final accumulate MTX release amounts are about 71% to 97%.

Plasma-treatment carbon nanotubes (CNTs) grafted with maleic anhydride (MA) were embedded in polyacryonitrile nanofibers via electrospinning and subsequently carbonizated at 800 °C to fabricate carbon nanofibers (CNFs). The grafted degree of MA on CNTs (CNTs-MA) was determined via Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The morphology, surface composition and conductivity of the CNTs-MA/CNF were characterized using electron microscopy, X-ray photoelectron and electrochemical impedance spectroscopy, respectively. CNTs-MA not only affected the conductivity of the CNFs but also the types of the nitrogen functional groups that could be represented as active sites on the CNFs to enhance the performance of the supercapacitors. When 2.5 wt.% CNTs-MA was embedded in the CNFs, the highest conductivity was obtained at 5.2 s/cm, and the amount of pyridinic and pyrrolic species increased to 70.3%. However, the highest capacitance was not obtained with 2.5 wt.% CNTs-MA added because of current leakage present in the system. The highest capacitance was 382 F/g with 1.0 wt.% CNTs-MA embedded in CNF with proper conductivity of 2.2 s/cm. Furthermore, galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy measurements also demonstrated that 1.0 wt.% CNTs-MA embedded in CNF resulted in better electrochemical reversibility and impendence properties.

To investigate the influence of the asymmetric ratio of polystyrene-block-poly(methyl methacrylate) (PS- b -PMMA) on the crystallization rate of polylactide (PLA), we synthesized PS- b -PMMA samples featuring distinct asymmetric ratios by using mercaptan/e-caprolactam living polymerization and subsequently melt-blended the polymers with PLA. Optical micrographs showed that the PMMA block facilitated the dispersion of PS- b -PMMA in the PLA matrix because of the favorable miscibility between PLA and PMMA. The results of nonisothermal and isothermal experiments indicated that adding 0.5 wt% PS- b -PMMA increased the crystallization rate of PLA when the value of the asymmetric ratio was ⩽4. However, when the asymmetric ratio of PS- b -PMMA approached 6, the long-chain PMMA block retarded the chain mobility of PLA and lowered the crystallization rate. The results of polarization optical microscopy revealed that incorporation of PS- b -PMMA enhanced the crystallization rate of PLA through heterogeneous nucleation. The PS block in the PLA matrix provided the nucleation sites, whereas the PMMA block interacted with the PLA polymer chain and facilitated crystal growth. Lastly, wide-angle X-ray diffraction patterns suggested that incorporating PS- b -PMMA in the PLA matrix did not change the crystalline structure of PLA when the block-length ratio between PS and PMMA was varied. The asymmetric ratio of PS- b -PMMA strongly influenced the crystallization, and we optimized the asymmetric ratio of PS- b -PMMA in order to accelerate PLA crystallization.

Poly(styrene-butadiene-styrene) (SBS) copolymer was used to enhance the crystallization ability and mechanical properties of poly(L-lactic acid) (PLA) through melt mixing. The thermogravimetric analysis and Fourier transform infrared results revealed the n–π interaction between PLA and SBS. Differential scanning calorimetry and X-ray diffraction analysis indicated that the crystallization ability of the PLA improved substantially. The PLA crystallized completely during the cooling process when the SBS content in the blend was above 20 wt.%. The elongation at break and the impact resistance were significantly improved compared with that of neat PLA when the SBS content was above 50 wt.%.

The usage of green polymers are widely increased from day-to-day as detergent builders, paper-sizing agents, flocculants, thickeners, emulsifiers, and scale inhibitors due to their friendly nature with the water systems. Minimizing the formation of inorganic scale deposits in processing industrial waters presents a challenge for water treatment systems. In the present investigation, we have developed water soluble green polymers based on malic acid (MA) and citric acid (CA) through a bulk-melt condensation process and applied as water scaling inhibitors. The copolymer of poly(malic acid-citric acid) (PMC) was synthesized by varying the ratio of MA and CA monomers with 1:3, 1:1, and 3:1, and studied their descaling property with carbonate, sulfate and phosphate ions. The scale inhibition property of the homopolymers was also investigated and compared with the copolymers. As the ratio of CA was increased in the copolymer formation, there was a greater influence on the scale inhibition. Interestingly, copolymers showed the highest phosphate inhibition (98%) and have no significant change with its homopolymers. The results indicate that the synthesized green copolymers PMC were water soluble, biodegradable, non-toxic and hence, have a good water descaling property without disturbing the taste, quality and purity of water. Characterization techniques such as Fourier Transform Infrared Spectroscopy (FTIR) analysis and Thermal Gravimetric Analysis (TGA) were performed in order to understand its thermal properties and copolymer confirmation.

The combination of electrospinning and forcespinning (otherwise called electrostatic-centrifugal spinning) was first proposed in our laboratory. A viscoelastic jet has a stretching force in the axial ( a x → ) and tangential ( a y → ) directions under electrostatic and centrifugal forces. The jet radius (R0) will be dramatically decreased, and the jet velocity (υ0) will be substantially increased due to a particular stretching force. The radius of curvature, the jet length, and the Taylor cone of a viscoelastic jet will be completely different when the jet velocity (υ0) increases. A strong stretching force and a fast extension speed will form after optimizing the radius of curvature (by Reynolds (Re) and Weber (We) numbers), jet length (by Peclet (Pe) and Epsilon (e) numbers), and Taylor cone (by dimensionless stress (Π1) and Ohnesorge (Oh) numbers). Through dimensionless number and group analysis, higher Re(PC = 9.38 × 10−2, PLA = 1.52 × 10−1 and PAN = 1.53 × 10−2) and We(PC = 13.8, PLA = 15 and PAN = 13.3) number of all three systems can collect the bead-free and uniform nanofibers. Similarly, higher П1(PC = 1.83 × 10−5, PLA = 2.86 × 10−5 and PAN = 5.13 × 10−9) and Oh(PC = 39.60, PLA = 29.22 and PAN = 238.94) numbers refer to viscosity and electrostatic force dominate the jet behavior and obtained the nanofiber with high modulus, hardness, crystallinity and good molecular orientation. Hence, the uniaxially aligned polycarbonate, polylactic acid and polyacrylonitrile nanofibers with superior physical properties (modulus ⩾ 2.77 GPa, 3.3 GPa and 1.46 GPa, hardness ⩾ 0.32, 0.26 and 0.22 and crystallinity ⩾ 3%, 37% and 21%) can be successfully manufactured in this process.

A polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) exhibiting a well-defined structure was prepared combining anionic polymerization and mercaptan/e-caprolactam living polymerization. To evaluate how this block copolymer affected the crystallization of polylactide (PLA), 0.5 wt % thiol-terminated PS homopolymer (PSSH), PMMA, and PS-b-PMMA was melt-blended with PLA. The calorimetric characterization of the nonisothermal and isothermal crystallization behavior was analyzed according to Avrami's theory, indicating that PS-b-PMMA more effectively increased the crystallization kinetics of the PLA matrix than did PSSH or PMMA. The results revealed that the synergistic effect of the PS and PMMA blocks appeared only when they were simultaneously presented in the PLA matrix. The PS block increased the number of nucleation sites and decreased the spherulite size, whereas the PMMA block facilitated the excellent dispersion of PS-b-PMMA in the PLA matrix as shown in polarizing optical microscope experiments. Incorporating PS-b-PMMA improved the PLA crystallization rate by promoting heterogeneous nucleation. In addition, incorporating 0.5 wt % PS-b-PMMA increased the relative crystallinity of PLA to 43.5%, and decreased the crystallization half-time to 2.4 min when the blend was isothermal at 105 °C. The PLA crystal structure was unchanged by the presence of PS-b-PMMA; however, the crystallization rate was enhanced as probed by SEM and X-ray diffraction. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 823–832

Modified masterbatch method comprising of the wet kneading and intercalated modifiers process was successfully applied to prepare exfoliated polylactic acid (PLA) clay hybrids. The crystallization rate of PLA/clay nanocomposite was improved by introducing alkylamide, an intercalated modifier with higher crystallinity. Both XRD and TEM analyses showed that the exfoliated and partially intercalated PLA nanocomposites can be obtained. The effect of clay and intercalated modifier on the nonisothermal, isothermal crystallization kinetics, and morphology of PLA was investigated using DSC instrument. The PLA nanocomposites showed faster crystallization rate because the alkylamide modifier act as a nucleation agent that successfully promoted crystallization. Notably, the crystallinity of PLA/clay hybrids dramatically increased from 9.0 to 42.1 %. The nucleation and crystal growth rate of PLA when crystallized from melt state is greatly influenced by the presence of organoclays. Therefore, as revealed from this isothermal crystallization investigation, the crystallization rate is enhanced by a factor of about 7–17.

Carbon nanotubes (CNTs) have been considered as promising materials in various applications including water treatment. Manipulation of CNT’s with polymer offers unique properties as a composite in treatment of wastewater and removal of heavy metal ions. In the present work, we have developed a chitosan (CS)/multiwall carbon nanotubes (MWCNTs) composite sorbent by mixing the naturally occurring biopolymer CS and functionalized MWCNTs in 1% acetic acid solution. The obtained composite adsorbent was used successfully for the removal of copper (II) ions from aqueous solutions. The influence of variable parameters like pH, concentration of the metal ion, amount of adsorbent, and contact time on the extent of adsorption was investigated by batch method. Graphical correlations of various adsorption isotherm models such as Langmuir and Freundlich have been carried out. The data were analyzed by the Lagergren pseudo-first-order and pseudo-second-order kinetic models. Further the adsorption performance of t...

A novel in situ chemical precipitation method to directly synthesize CdS nanocrystal arrays in the presence of microporous templates of poly(glycidyl methacrylate-grafted-3,3′-dimethyl-(4-hydroxyphenylazanediyl) bis(2-methylpropanoate))-random-polystyrene (PGHS), which were formed by self-assembling dendritic-linear PGHS copolymers via the solvent-induced phase separation process, were investigated. The surface morphology of the PGHS template and the spatial positions of the CdS nanocrystals in the PGH-CdS could be easily and quickly controlled by altering the content of the dendritic GMA-HPAM segments. The diameters of the CdS nanocrystals on the PGHS-CdS template were uniform in the range of 3–4 nm. Large-area, hexagonally ordered CdS nanocrystal-array domains were discovered in the PGHS2-CdS template used in this study.

A series of dendritic-linear copolymers, composed of poly(glycidyl methacrylate-grafted- 3,3′-dimethyl-(4-hydroxyphenylazanediyl) bis(2-methylpropanoate))-random-polystyrene (PGMA-HPAM-r-PS), were successfully synthesized via a macromonomer route. Characterization of the copolymers and investigation of their thermal behavior revealed a significant influence of the dendritic GMA-HPAM segment. The thermal degradation temperature (Td) of the dendritic-linear PGMA-HPAM-r-PS copolymer was elevated as the weight percentage of dendritic segment (GMA-HPAM) increased. The glass transition temperatures of the copolymers exhibited a strong, complex dependence on the dendritic GMA-HPAM segment, with three behavioral ranges. DSC data were attributed to two distinct effects of the dendritic segment: (i) the effect of the dendritic segment grafting on copolymer chains, and (ii) intermolecular interactions between the dendritic and styrene segments. Microporous dendritic-linear PGMA-HPAM-r-PS copolymer matrices were prepared using solvent-induced phase separation at room temperature. The self-assembled surface morphology was affected by (i) the micellar domains of the dendritic and styrene segments and (ii) inter- and intramolecular interactions between the dendritic and styrene segments. An interesting relationship between thermal behavior and surface morphology was discovered, which can provide a simple, accurate and rapid means of finding the optimum dendritic segment content for producing a hexagonally ordered microporous matrix for different dendron generations.