Rod-like Structure Research Articles

Membraneless Photocatalytic Fuel Cell with Double Photoelectrodes for Simultaneous Electricity Generation and Pollutant Degradation

Environmental pollution and new energy development have become topics of increasing concern. Herein, a visible-light-driven photocatalytic fuel cell (PFC) with double photoelectrodes was constructed for simultaneous electricity generation and pollutant degradation, in which graphitic carbon nitride (g-C3N4) generated on W/WO3 nanorod arrays (W/WNR/g-C3N4) was used as the photoanode and Fe3+-doped CuBi2O4 thin film on indium tin oxide (ITO) conductive glass (ITO/CBFeO) was used as the photocathode. The experimental results showed that the WO3/g-C3N4 Z-scheme structure and one-dimensional WNR rod-like structure could effectively suppress the recombination of photogenerated charge carriers and enable W/WNR/g-C3N4 to present a good photocurrent response under visible light irradiation. The Fermi level mismatch between the W/WNR/g-C3N4 photoanode and ITO/CBFeO photocathode could improve the transfer of photogenerated electrons from the photoanode to the photocathode across the external circuit, enabling the constructed PFC to afford high electricity output and good efficiency for pollutant degradation. The short-circuit current density and maximum power density could reach 620 μA cm−2 and 110 μW cm−2, respectively, while the degradation ratio of oxytetracycline reached 97.6% in 90 min. Therefore, the proposed PFC system provides a new way to generate electric energy and degrade pollutants simultaneously.

A facile microwave-assisted combustion synthesis of NiCoFe2O4 anchored polymer nanocomposites as an efficient electrode material for asymmetric supercapacitor application

Renewable energy storage is very important and needs of the day for all handy electronic devices. Hybrid polymer nanocomposites (PNCs) have attracted great attention recently, for these applications. In the present work, nanostructure nickel-cobalt ferrite (NiCoFe2O4) dispersed Polyvinyl alcohol (PVA)/ Poly(vinyl) pyrrolidone (PVP) nanocomposites have been prepared by a simple solution casting method. Structural studies of prepared polymer nanocomposites have been established by X-ray diffraction analysis. The presence of functional and vibrational groups of polymer nanocomposites have been identified using FTIR spectroscopy. The surface characteristics of prepared PNCs have been obtained as a non-uniform rod-like structure with porous morphology in field emission scanning electron microscopy (FESEM). Temperature dependent dielectric and electronic spectral studies have been investigated. The electrochemical characteristics such as cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD) and electrical impedance spectroscopy (EIS) have been analyzed. This study resulted in maximum specific capacitance as 13.49 F g−1 at a current density of 1 A g−1 for 1 wt.% of NiCoFe2O4 (NCF) nanoparticles in polymer blended electrode and 99.39% of columbic efficiency. The supercapacitor with NCF loaded PVA/PVP as electrode is introducing an excellent prospective for practical supercapacitors owing to high surface area, good energy density and power density.

Promising solar photodegradation of RY 86 by hydrophilic F127 (pluronic) aided nano cobalt ferrite and its biomedical applications

To our surprise, we effectively excelled in developing the hydrophilic, non-ionic and water soluble triblock copolymer surfactant F127 (pluronic) aided spinel cobalt ferrite (CFO) nanoparticles. The crystalline nature and surface morphology of F127 aided CFO nanoparticles have been confirmed laboriously by XRD, HR-TEM, DLS, FT-RAMAN, FT-IR, UV-DRS, and SEM-EDX. SEM confirms undeclared rod-like structure and HR-TEM supports a shape similar to quasi-spherical morphology. The band gap investigation report that the Eg value of F127 aided CFO is around 1.24 eV. We found the fact that, in the UV/solar light degradation of hazardous Reactive Yellow 86 (RY 86), the photocatalytic activity of F127 aided CFO nanoparticles was accelerated by the presence of H2O2. F127 is a surfactant that played a key role in the enhanced activity of F127 aided CFO nanoparticles. By using an external magnetic field, the catalyst can be recovered from the fluid medium and thereby reused. The feasible mechanism for active liquid phase photodegradation of RY 86 has also been developed. Therefore, we assure that the novel spinel F127 aided CFO nanoparticles will shed more light for the wastewater treatment system because of its effective photocatalytic and reusable behavior. In conjunction, the antibacterial function and cytotoxicity are also performed.

Fabrication of low to high duty fireclay refractory bricks from lignite fly ash

The development of refractory bricks made of new materials has recently drawn a lot of interest to address sustainability issues. So, in this study, the recycling of lignite fly ash produced by coal-fired thermal power plants has been investigated to make fireclay refractory bricks. The lignite fly ash and ball clay are the primary raw materials characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray fluorescence (XRF), and differential thermal analysis (DTA). The samples were prepared using a uniaxial hydraulic press, and firing was done in the range of 1000–1200 °C for 2 h. The fired samples were characterized in terms of chemical composition, mineralogical phase, and microstructural using different characterization tools such as XRF, XRD, and SEM. The physical, mechanical, and thermal properties such as linear firing shrinkage, apparent porosity (AP), bulk density (BD), cold crushing strength (CCS), cold modulus of rupture (CMOR), and thermal conductivity of the fired sample were investigated. The linear firing shrinkage, AP, BD, and CCS values were achieved estimated to be 5.32%, 2.10 g m/cc, 15%, and 52 MPa, respectively. The SEM analysis shows dense, rod-like mullite structure and interlocking microstructure of the fired samples. The results were well matched with ASTM standards and commercially available products. So, this promising result indicates lignite fly ash can be used as a potential raw material to produce fireclay refractory bricks.

A non-specific surface area dominated catalytic ozonation with CuO modified β-MnO2 in efficient oxalic acid degradation

In this paper, a series of copper oxide supported manganese dioxide (CuXMnT) composites were prepared by the hydrothermal and deposition precipitation methods. The effects of different hydrothermal temperatures (100 °C–180 °C) and copper doping amounts (1–10 mM) on the structural and physicochemical properties of CuXMnT composites were systematically investigated. The BET, SEM, and XRD characterizations revealed that the CuXMnT composites exhibited a typical rod-like structure. Besides, with the increscent hydrothermal temperature, the BET specific surface area decreased and the crystal form of the composites changed from α-MnO2 to β-MnO2. The Cu1Mn180 with low specific surface area (3.277 m2 g−1) exhibited the splendid catalytic ozonation activity and the oxalic acid (OA) removal rate reached 87.5% in O3/Cu1Mn180 process compared with single ozonation (3.2%). Additionally, it was noteworthy that the excellent catalytic performance of Cu1Mn180 (91.8% of OA removal rate) at pH 3.0 was resulted from the electrostatic adsorption. While, the complexation played a vital role for OA degradation at pH 6.0 and 9.0 with the OA removal efficiencies of 87.5 and 70.3% within 30 min, respectively. Furthermore, Cu1Mn180 could obtain more than 90.9% of OA removal rate during multiple consecutive cycles, representing the satisfactory stability and reusability. Moreover, the multivalent Mn, the structural oxygen species, and Cu species played the key roles for OA degradation in O3/Cu1Mn180 process at pH 6.0 via the TEM, ESR, XPS and O2-TPD characterizations. Overall, the results presented a promising alternative material for efficient catalytic ozonation application in water.

Synthesis of porous rod-like In2O3 nanomaterials and its selective detection of NO at room temperature

The construction of gas sensors with excellent gas sensitivity and low operating temperature is of great importance while challenging. In this work, using indium nitrate, urea, and sucrose as precursors, In2O3 nanomaterials with the porous rod-like structure were prepared via hydrothermal method combined with high-temperature calcination. FTIR and TGA methods verified the growth process of porous rod-like In2O3 nanomaterials. Significantly, due to the doping of carbon in In2O3, the sensor based on porous rod-like In2O3 nanomaterials showed an enhancement response to NO at room temperature. The porous structure of In2O3 nanomaterials facilitates the diffusion of gas, shortening the response time. The developed materials provide insight into the fabrication of porous nanomaterials and the detection of NO at room temperature.

A facile morphology tunable strategy of Zn-MOF derived hierarchically carbon materials with enhanced supercapacitive performance through the solvent effect.

Metal-organic framework (MOF) derived porous carbon materials have been widely applied as active materials for supercapacitors due to their large specific surface area and ordered pore structure. This paper presents a facile and effective strategy to regulate the morphology of a zinc-based metal-organic framework (Zn-trimesic acid, Zn-BTC) by adjusting the ethanol content in a solvent, which can effectively change the pore structure of Zn-BTC derived porous carbon (PC). The optimal PC prepared in 50% ethanol displays a rodlike structure with a large specific surface area (SSA) of 1930 m2 g-1 and an average pore size of 2.9 nm. This material shows an excellent rate performance with 78.8% capacitance retention when the current density increases from 1 A g-1 to 100 A g-1 and outstanding electrochemical stability with only 2.2% decline of capacitance after 200 000 cycles at 50 A g-1. Moreover, the assembled symmetrical capacitor shows a high energy density of 16.09 W h kg-1 at 698 W kg-1 and 11.89 W h kg-1 at a high power density of 41.56 kW kg-1. This method would provide a new pathway for the preparation of carbon materials with an adjustable pore size for high-performance supercapacitors.

Preparation of prismatic g-C3N4 by CTAB hydrothermal method and its degradation performance under visible light

In this paper, the growth mechanism of prismatic carbon nitride at different temperatures was studied by using the mixed solution of CTAB and NaOH by thermal polycondensation-hydrothermal method, and a series of characterization methods were used to analyze and verify. The pollutant model MO solution was degraded and its photocatalytic activity was investigated under light. The results show that at a relatively low temperature, g-C3N4 is a rod-like structure, and NaOH plays a major role. With the increase of temperature, CTAB plays a major role and can transport the primitives to form a rod, but also forms an ordered hydrophobic film on the crystal plane, which inhibits the growth of the rod-like structure on the (100) crystal plane and controls the extension on the (002) crystal plane. Its degradation rate is about 2.64 times that of pure g-C3N4. This significantly improves the separation rate of photogenerated electrons and the photocatalytic degradation efficiency.

Mesoporous carbon rods capable of fast transport of axial electrons and radial ions for ultra-thick supercapacitor electrodes

Increasing the energy density (Ewt) under large currents is always highly desired for supercapacitors using thick carbon electrodes. Herein, we report an ultra-thick carbon electrode composed of mesoporous carbon rods (MCR) with ultrahigh specific surface area. At 250 μm, it exhibits the highest capacitance (Cwt, 239 F g − 1 at 1 A g − 1) and Cwt retention (53% at 100 A g − 1) in EMIMBF4 as far as we know, and ultrahigh Ewt (132 Wh kg−1) and achievable power density (Pwt, 74 kW kg−1). Even at ultra-thick 600 μm, its Ewt and Pwt are still up to 95 Wh kg−1 and 70 kW kg−1, respectively, with the decay of Cwt at 50 A g − 1 < 3% (much smaller than commercial carbon YP-50F). Such excellent performance is attributed to the unique MCR structure, i.e., the micron-sized rod-like frame structure consisted of interconnected carbon nanocages acting as axial electron channel, as well as the stacking pores formed by MCR serving as radial channels for ions, finally enabling electrons and ions to be rapidly transferred in the axial and radial directions, respectively. It fully demonstrates its potential application prospects in scenarios requiring high energy and high power at the same time.

The potential of Co3O4 nanoparticles attached to the surface of MnO2 nanorods as cathode catalyst for single-chamber microbial fuel cell

A simple two-step hydrothermal method was used to prepare the cathode catalyst of microbial fuel cell (MFC). MnO2@Co3O4 composite was successfully prepared by in-situ growth of nano-particle-like Co3O4 on nano-rod-like MnO2. The hybrid products had (121), (310), (311), (400) and (511) crystal planes, rod-like and point-like structures were observed. MnO2@Co3O4 nanohybrids were rich in a variety of metallic elements and provided rich electrochemically active sites. The maximum voltage of MnO2@Co3O4-MFC was 425 mV, the maximum stabilization time was 4 d. The maximum output power was 475 mW/m2, which was 2.24 times that of Co3O4-MFC (212 mW/m2) and 2.63 times of MnO2-MFC (180 mW/m2). The rod-like structure of MnO2 could effectively improve the ion flow efficiency and reduce the transfer resistance, and the point-like structure of Co3O4 can increase the specific surface area of the complex and provide more active sites.

Structural Insights into Self-Assembled Aerosol-OT Aggregates in Aqueous Media Using Atomistic Molecular Dynamics.

In water, the surfactant dioctyl sulfosuccinate (Aerosol-OT or AOT) exhibits diverse aggregate structures, ranging from micelles to lamella. An atomic-level understanding, however, of the formation and structure of these aggregates is lacking. Herein, using atomistic molecular dynamics (MD) with microsecond-long simulations, self-assembly of AOT in water is studied for concentrations of 1, 7.2, and 20 wt % at 293 K and for 7.2 wt % at 353 K. Assembly proceeds through stepwise association and dissociation of single AOT molecules, and the fusion and fission of AOT clusters. At 293 K, AOT self-assembles into either (i) spherical micelles (1 wt %), (ii) biphasic systems consisting of rod-like and prolate spheroidal micelles (7.2 wt %), or (iii) bilayers (20 wt %). We hypothesize that the observed rod-like structure is a precursor to lamellar microdomains found experimentally in biphasic dispersions. Increasing temperature to 353 K at 7.2 wt % results in a system consisting of prolate micelles but no rod-like micelles. Simulated phase behavior agrees with previously published experimental observations. Individual aggregates formed during self-assembly are identified using graph theory. Structural metrics of these aggregates like the radius of gyration, shape anisotropy, and prolateness are presented. Trends in structural metrics quantitatively reflect how shapes and sizes of AOT aggregates vary with surfactant concentration and temperature. These simulations provide deeper insight into open questions in the scientific community and demonstrate a method to generate physics-based micelle structures that can be used to rationalize experimental observations.

Effect of Rod-like Structure on Fatigue Life, Short Surface Crack Initiation and Growth Characteristics of Extruded Aluminum Alloy A2024 (Analysis via Modified Linear Elastic Fracture Mechanics).

In the Al alloy A2024-T3 extruded material, a rod-like structure is generated parallel to the extrusion direction. In this study, the effects of rod-like structures on fatigue crack initiation and growth behavior were comprehensively investigated. Two types of specimens were used in a fatigue experiment, in which the direction of the load stress amplitude was parallel (specimen P) and perpendicular (specimen V) to the rod-like structure. Based on the experimental and analytical results, the following findings were obtained regarding the fatigue life, location of crack initiation, and fatigue crack growth behavior. Because the fatigue life of specimen P was longer than that of specimen V, it is inferred that the rod-like structure significantly affects the fatigue life. In specimen P, fatigue cracks were generated from the grain boundaries of the Al matrix. By contrast, in specimen V, cracks were generated from the Cu–Mg-based intermetallic compound in the Al matrix. In specimen P, fatigue cracks were more likely to propagate across the rod-like structure, which decreased the fatigue crack growth rate. In specimen V, fatigue cracks did not propagate across the rod-like structure; instead, they propagated through the Al matrix. Therefore, the fatigue crack growth resistance of specimen V was lower than that of specimen P. The relationship between the fatigue crack growth rate and the modified linear elastic fracture mechanics parameter could be used to predict the S–N curve (stress amplitude vs. fatigue life) and fatigue crack growth behavior. The predicted results agreed well with the experimental results.

Isolation and Characterization of Nanocrystalline Cellulose Isolated from Pineapple Crown Leaf Fiber Agricultural Wastes Using Acid Hydrolysis.

Pineapple crown leaf fiber (PCLF) is one of the major biomass wastes from pineapple processing plants. It consists mostly of carbohydrate polymers, such as cellulose, hemicellulose, and lignin. It can be further processed to form a more valuable and widely used nanocrystalline cellulose (NCC). This study investigates the effect of hydrolysis time on the properties of the produced NCC. The acid hydrolysis was conducted using 1 M of sulfuric acid at hydrolysis times of 1–3 h. The resulting NCCs were then characterized by their morphology, functional groups, crystallinity, thermal stability, elemental composition, and production yield. The results show that the NCC products had a rod-like particle structure and possessed a strong cellulose crystalline structure typically found in agricultural fiber-based cellulose. The highest NCC yield was obtained at 79.37% for one hour of hydrolysis. This NCC also displayed a higher decomposition temperature of 176.98 °C. The overall findings suggest that PCLF-derived NCC has attractive properties for a variety of applications.

Metal-organic framework-derived Mn3O4 nanostructure on reduced graphene oxide as high-performance supercapacitor electrodes

Metal oxide derived from metal-organic framework (MOF) could possess unique architecture and special properties. In this work, hierarchically nanostructured Mn3O4 is synthesized from the thermal annealing of manganese-1,3,5-benzenetricarboxylate (Mn-BTC) MOF with the presence of reduced graphene oxide (rGO) to yield rGO/Mn3O4 composite for the high-performance supercapacitor electrode material. The porous rGO aerogel is prepared from the hydrothermal and freeze-drying processes. The effective combination of Mn-BTC and rGO aerogel is realized through a facile ball-milling method that endows Mn-BTC with a rod-like structure in the composite. Upon annealing, the Mn-BTC-derived Mn3O4 presents the unique structure of porous rods comprising nanoparticles in the resulting rGO/Mn3O4 composite. The optimized rGO/Mn3O4/Ni foam electrode achieves a specific capacitance of 420 F g−1 at 0.5 A g−1 and a superior cycling property. The assembled all-solid-state symmetric supercapacitor based on rGO/Mn3O4 composite delivers the energy density of 22.1 Wh kg−1 and power density of 3.0 kW kg−1. The excellent capacitive performance of the rGO/Mn3O4 electrode could be ascribed to the effective integration of Mn-BTC-derived manganese oxides with hierarchical structure and the rGO matrix, facilitating the ion/electron transport in the electrochemical process.

Structural and Optical Properties of Pure NiO Nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO-ZnO Nanocomposites

Abstract: Pure nickel oxide (NiO) nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO –ZnO nanocomposites were synthesized by co-precipitation method. The PXRD studies revealed that NiO, Mn2O3 and CdO possessed cubic structure, Pb2O3 possessed monoclinic structure, ZnO possessed hexagonal structure and confirmed the presence of polycrystallinity nature of NiO and Mn2O3, CdO, Pb2O3, ZnO in the nanocomposites. The average grain size of NiO nanoparticles was found to be 30.10 nm using Debye Scherer’s formula. The FESEM images of NiO nanoparticles and their nanocomposites revealed spherical shaped structure and NiO-Pb2O3 revealed needle shaped rod-like structure. EDAX analysis confirmed the composition of NiO nanoparticles and their nanocomposites. Raman spectra exhibited characteristic peaks of pure NiO and that of NiO- Mn2O3, NiO-CdO, NiO- Pb2O3, NiO-ZnO in the synthesized nanocomposites. In the PL spectra, blue and green emission was observed in the samples. UV-vis spectra revealed the absorption peaks of NiO nanoparticles and their nanocomposites. Thus, the synthesized NiO- Mn2O3, NiO-CdO, NiO - Pb2O3 and NiO-ZnO nanocomposites can be a suitable material for electrocatalysis applications. Keywords: Nickel oxide nanocomposites, Structure, Morphology, Absorption, Luminescence.

Environmental Remediation of Toxic Organic Pollutants Using Visible-Light-Activated Cu/La/CeO2/GO Nanocomposites.

Environmental pollution is a major threat that increases day by day due to various activities. A wide variety of organic pollutants enter the environment due to petrochemical activities. Organic contamination can be unsafe, oncogenic, and lethal. Due to environmental issues worldwide, scientists and research communities are focusing their research efforts on this area. For the removal of toxic organic pollutants from the environment, photocatalysis-assisted degradation processes have gained more attention than other advanced oxidation processes (AOPs). In this manuscript, we report a novel photocatalysis of copper and lanthanum incorporating cerium oxide (CeO2) loaded on graphene oxide (Cu/La/CeO2/GO) nanocomposites successfully synthesized by hydrothermal techniques. XRD results showed the presence of dopant ions and a crystalline structure. FESEM images showed that the surface morphology of the synthesized nanocomposites formed a rod-like structure. The highlight of this study is the in-situ synthesis of the novel Cu/La/CeO2/GO nanocomposites, which manifest higher photodegradation of harmful organic dyes (Rhodamine B (RhB), Sunset Yellow (SY), and Cibacron Red (CR)). In Cu/La/CeO2/GO nanocomposites, the dopant materials restrict the rapid recombination of photoinduced electron–hole pairs and enhance the photocatalytic activity. The degradation percentages of RhB, SY, and CR dye solution are 80%, 60%, and 95%, respectively. In summary, the synthesized nanocomposites degrade toxic organic dyes with the help of visible light and are suitable for future industrial applications.

Fabrication of Cellulase Catalysts Immobilized on a Nanoscale Hybrid Polyaniline/Cationic Hydrogel Support for the Highly Efficient Catalytic Conversion of Cellulose.

A novel conductive nanohydrogel hybrid support was prepared by in situ polymerization of polyaniline nanorods on an electrospun cationic hydrogel of poly(ε-caprolactone) and a cationic phosphine oxide macromolecule. Subsequently, the cellulase enzyme was immobilized on the hybrid support. Field-emission scanning electron microscopy and Brunauer-Emmett-Teller analyses confirmed a mesoporous, rod-like structure with a slit-like pore geometry for the immobilized support and exhibiting a high immobilization capacity and reduced diffusion resistance of the substrate. For comparison, the catalytic activity, storage stability, and reusability of the immobilized and free enzymes were evaluated. The results showed that the immobilized enzymes have higher thermal stability without changes in the optimal pH (5.5) and temperature (55 °C) for enzyme activity. A high immobilization efficiency (96%) was observed for the immobilized cellulose catalysts after optimization of parameters such as the pH, temperature, incubation time, and protein concentration. The immobilized enzyme retained almost 90% of its original activity after 4 weeks of storage and 73% of its original activity after the ninth reuse cycle. These results strongly suggest that the prepared hybrid support has the potential to be used as a support for protein immobilization.

Lignocellulose nanocrystals from pineapple peel: Preparation, characterization and application as efficient Pickering emulsion stabilizers

In this study, the pineapple peel treated with different degrees of delignification was used to isolate lignocellulose nanocrystals (LCNC) by sulfuric acid hydrolysis. Controlling delignification treatments can adjust the morphology and structure of pineapple peel and the retention of lignin, thereby achieving the regulation of the properties of LCNC, such as morphology, crystallinity, hydrophobicity and rheological properties. The results of atomic force microscope (AFM), confocal laser scanning microscopy (CLSM), UV/visible (UV–Vis) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the presence of lignin in LCNC, showing a rod-like structure with the distribution of lignin. Regulating delignification of pineapple peel can adjust the average length (310 ∼ 460 nm), diameter (19 ∼ 38 nm), crystallinity (61% ∼ 71%) and hydrophobicity (contact angle 84° ∼ 60°) of the obtained LCNC by acid hydrolysis, and influence the performance of its stabilized Pickering emulsions. This work confirms that the properties of LCNC can be controlled through adjusting delignification degree, possessing great significance for the high value utilization of lignocellulosic agricultural waste.

Alkyne-Palladium(II)-Catalyzed Living Polymerization of Isocyanides: An Exploration of Diverse Structures and Functions.

Inspired by the perfect helical structures and the resulting exquisite functions of biomacromolecules, helical polymers have attracted increasing attention in recent years. Polyisocyanide is well known for its distinctive rodlike helical structure and various applications in chiral recognition, enantiomer separation, circularly polarized luminescence, liquid crystallization, and other fields. Although various methods and catalysts for isocyanide polymerization have been reported, the precise synthesis of helical polyisocyanides with controlled molecular weight, low dispersity, and high tacticity remains a formidable challenge. Owing to a limited synthesis strategy, the controlled synthesis of topological polyisocyanides has barely been realized. This Accounts highlights our recent endeavors to explore novel catalysts for the living polymerization of isocyanides. Fortunately, we discovered that alkyne-Pd(II) catalysts could initiate the living polymerization of isocyanides, resulting in helical polyisocyanides with controlled structures, high tacticity, and tunable compositions. These catalysts are applicable to various isocyanide monomers, including alkyl isocyanides, aryl isocyanides, and diisocyanobenzene derivatives. Incorporating chiral bidentate phosphine ligands onto alkyne-Pd(II) complexes formed chiral Pd(II) catalysts, which promoted the asymmetric living polymerization of achiral isocyanide, yielding single left- and right-handed helices with highly optical activities.Using alkyne-Pd(II) catalysts, various topological polyisocyanides have been facilely prepared, including hybrid block copolymers, bottlebrush polymers, core cross-linked star polymers, and organic/inorganic nanoparticles. For instance, various hybrid block polyisocyanides were easily produced by coupling alkyne-Pd(II)-catalyzed living isocyanide polymerization with controlled radical polymerization and ring-opening polymerization (ROP). Combining the ring-opening metathesis polymerization (ROMP) of norbornene with Pd(II)-catalyzed isocyanide polymerization, bottlebrush polyisocyanides and core cross-linked star polymers were easily prepared. Pd(II)-catalyzed living polymerization of poly(lactic acid)s with isocyanide termini resulted in densely grafted bottlebrush polyisocyanides with closely packed side chains. Moreover, the surface-initiated living polymerization of isocyanides produced a family of polyisocyanide-grafted organic/inorganic hybrid nanoparticles using nanoparticles with alkyne-Pd(II) catalysts anchored on the surfaces. Surprisingly, the nanoparticles and star polymers with helical polyisocyanide arms performed exceptionally well in terms of chiral recognition and resolution. Incorporated organocatalysts such as proline and prolinol units onto the pendants of optically active helical polyisocyanides, a family of polymer-based chiral organocatalysts, were generated, which showed significantly improved stereoselectivity for the asymmetric Aldol reaction and Michael addition and can be easily recycled.Using a chiral alkyne-Pd(II) catalyst, single-handed helical polyisocyanides bearing naphthalene and pyrene probes were produced from achiral isocyanide monomers. These polymers showed excellent self-sorting properties as revealed using a fluorescence resonance energy transfer (FRET) investigation and were self-assembled into two-dimensional (2D) smectic nanostructures driven by both helicity and chain length. Incorporating helical poly(phenyl isocyanide) (PPI) onto semiconducting poly(3-hexylthiophene) (P3HT) induced the asymmetric assembly of the resulting P3HT-b-PPI copolymers into single-handed cylindrical micelles with controlled dimensions and tunable photoluminescence.

Systematic Investigation of Solution-State Aggregation Effect on Electrical Conductivity in Doped Conjugated Polymers

Systematic Investigation of Solution-State Aggregation Effect on Electrical Conductivity in Doped Conjugated Polymers