Ultrafast Microwave Nano-manufacturing of Fullerene-Like Metal Chalcogenides.

Metal Chalcogenides (MCs) have emerged as an extremely important class of nanomaterials with applications ranging from lubrication to energy storage devices. Here we report our discovery of a universal, ultrafast (60 seconds), energy-efficient, and facile technique of synthesizing MC nanoparticles and nanostructures, using microwave-assisted heating. A suitable combination of chemicals was selected for reactions on Polypyrrole nanofibers (PPy-NF) in presence of microwave irradiation. The PPy-NF serves as the conducting medium to absorb microwave energy to heat the chemicals that provide the metal and the chalcogenide constituents separately. The MCs are formed as nanoparticles that eventually undergo a size-dependent, multi-stage aggregation process to yield different kinds of MC nanostructures. Most importantly, this is a single-step metal chalcogenide formation process that is much faster and much more energy-efficient than all the other existing methods and can be universally employed to produce different kinds of MCs (e.g., MoS2, and WS2).

Ultrafast Microwave Welding/Reinforcing Approach at the Interface of Thermoplastic Materials.

As an attempt to address the needs and tackle the challenges in welding of thermoplastic materials (TPMs), a novel process was performed via short-term microwave (MW) heating of a specific composite, made up of conducting polypyrrole nanogranule (PPy NG) coated carbon and catalyst source precursor (ferrocene) fine particles, at substrate polypropylene (PP) dog bone pieces' interface. Upon vigorous interactions between MWs and electromagnetic absorbent PPy NG coating, the energy was transformed into a large amount of heat leading to a drastic temperature increase that was simultaneously used for the instant carbonization of PPy and the decomposition of fine ferrocene particles, which resulted in multiwalled carbon nanotubes (CNTs) growth at the interface. Meanwhile, the as-grown CNTs on the surface conveyed the heat into the adjacent bulk PP and caused locally molten surface layers' formation. Eventually, the light pressure applied at the interface during the heating process squeezed the molten layers together and a new weld was generated. The method is considerably advantageous compared to other alternatives due to (i) its fast, straightforward, and affordable nature, (ii) its applicability at ambient conditions without the need of any extra equipment or chemicals, and also (iii) its ability to provide clean, durable, and functional welds, via precisely controlling process parameters, without causing any thermal distortion or physical alterations in the bulk TPM. Thus, it is believed that this novel welding process will become much preferable for the manufacturing of next-generation TPM composites in large scale, through short-term MW heating.

One-step synthesis and characterization of polyaniline nanofiber/silver nanoparticle composite networks as antibacterial agents.

Through a facile and effective seeding polymerization reaction via a one-step redox/complexation process, which took place in aqueous medium at ambient temperature, silver nanoparticles (Ag NPs) embedded polyaniline nanofiber (PANI NF) networks were synthesized as antibacterial agents. During the reaction, not only NF morphology formation of the resulting conducting polymers (CPs) but also amplification of the aqueous silver nitrate (AgNO3) solutions' oxidative potentials were managed by vanadium pentoxide (V2O5) sol-gel nanofibers, which acted as well-known nanofibrous seeding agents and the auxiliary oxidative agent at the same time. The PANI/Ag nanocomposites were proven to exhibit excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Antibacterial property performance and average life span of the nanocomposite network were optimized through the homogeneous distribution/embedment of Ag NPs within one-dimensional (1-D) PANI NF matrix. The antibacterial efficacy tests and nanocomposite material characterization results further indicated that the sole components of PANI/Ag have a synergistic effect to each other in terms of antibacterial property. Thus, this well-known catalytic seeding approach via a one-step oxidative polymerization reaction can be considered as a general methodology and a substantial fabrication tool to synthesize Ag NP decorated nanofibrillar PANI networks as advanced antibacterial agents.

Ultrafast Cr(VI) removal from polluted water by microwave synthesized iron oxide submicron wires.

Iron oxide submicron wires are successfully synthesized via a microwave irradiation method within a short period of 20 s. Upon reduction, this material shows orders of magnitude faster Cr(VI) removal rate than conventional adsorbents. A redox reaction based removal mechanism is revealed instead of adsorption.

One-pot formation of multifunctional Pt-conducting polymer intercalated nanostructures.

A novel multifunctional Pt nanoparticle@PPy nanofiber intercalated structure (Pt NP@PPy NF) has been synthesized facilely in one-pot. Pt NPs, with size and facet control, were nicely assembled and embedded into the polymer nanofiber network. Polyvinylpyrrolidone (PVP) was used during the synthesis process which would assist the self-assembly of the metal nanoparticles and polymer backbones into the intercalated structure. Space-confined distribution of the Pt NPs was achieved within the large dimension PPy nanofiber network, which could enhance the interfacial electron transfer process as well as diminish the catalyst deformation. The as-formed Pt NPs have a cluster-like structure and are mainly composed of 3.5 nm primary Pt particles with (100) surface atoms. Enhanced electrocatalytic properties were shown by the Pt NP@PPy NF intercalated structure, with sufficiently high enzyme-less glucose biosensitivity and a long linear range from 1-30 mM (R = 0.9995). High electrochemical cycling stability, chloride (Cl(-)) tolerance and good selectivity are also obtained for the Pt NP@PPy NF structure, as the electrode showed no obvious response to the common interfering agents, such as ascorbic acid (AA), uric acid (UA), and 4-acetamidophenol (AP). Furthermore, the Pt NP@PPy NF showed excellent catalytic activity for the methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR), which displayed sufficient CO tolerance, and higher activity compared to the commercial Pt/C catalyst. This intrinsically multifunctional Pt NP@PPy NF with well-controlled Pt facets thus could serve as an advanced electrocatalyst for biosensing and fuel cell applications, surpassing the performance of many existing materials.

Controlled synthesis of transition metal/conducting polymer nanocomposites.

A novel displacement reaction has been observed to occur between conducting polymers (CP) and metal salts which can be used to fabricate nanostructured CP-metal composites in a one-pot manner. Vanadium pentoxide (V(2)O(5)) nanofiber is used during the synthesis as the reactive seeds to induce the nanofibril CP-metal network formation. The CP-metal nanocomposites exhibit excellent sensory properties for hydrogen peroxide (H(2)O(2)) detection, where both high sensitivity and a low detection limit can be obtained. The sensory performance of the CP-metal composite can be further enhanced by a facile microwave treatment. It is believed that the CP-metal nanofibril network can be converted to a carbon-metal network by a microwave-induced carbonization process and result in the sensory enhancement.

Facile synthesis of polypyrrole coated copper nanowires: a new concept to engineered core-shell structures.

Polypyrrole coated copper nanowires were synthesized in a one-pot manner in the presence of cupric precursor and pyrrole. They displayed ultra-high sensitivity as a potentiometric sensor with considerable environmental stability comparable to noble metals.

Seeding approach to noble metal decorated conducting polymer nanofiber network.

Metal displacement reactions between conducting polymers-"synthetic metals"-and noble metals (Pt, Au and Ag) have been demonstrated using a seeding polymerization technique, to produce a synthetic metal nanofiber network decorated with noble metal nanoparticles, in one-step.

Poptube approach for ultrafast carbon nanotube growth.

Microwave irradiation can be used to heat conductive materials and metallocene precursors to initiate ultrafast CNT growth. It takes only 15-30 seconds to grow CNTs at room temperature in air, without the need for any inert gas protection and additional feed stock gases.

Green-nano approach to nanostructured polypyrrole.

Bulk quantities of polypyrrole nanofibers and nanospheres can be synthesized with a facile, one-step "green-nano" chemical oxidative polymerization approach, by simply using different reaction media.

Oxidative template for conducting polymer nanoclips.

Bulk quantities of electronic conducting polymers such as polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene), having an unusual 2D nanoclip-like morphology is described using a general oxidative template assembly route which is orchestrated by an insoluble complex formed between an anionic oxidant (S(2)O(8)(2-)) and a cationic surfactant.