Grafting of Organophosphonic Acid Monolayers on Hydrogen-Terminated Silicon Surface and Secondary Functionalization in Supercritical Carbon Dioxide Media.

The monolayer grafting on the oxide-free Si surface is challenging due to vulnerability of the surface against oxide formation in an ambient atmosphere. Most of the conventional studies focused on organic solvent-based chemistry and solvent and substrate interfaces, and residual solvents after the monolayer grafting play a key role in producing the highly stable monolayers. CO in its supercritical state (SCCO) provides an elegant engineering solution for the problem faced as it can be used as inert processing environment and as carrier fluid for monolayer grafting taking up the role of organic solvents.

Universal Single-Step Approach to the Immobilization of Cyclodextrins in a Supercritical Medium for Capturing Drug, Dye, and Metal Nanoclusters.

By utilizing nanoreactor-like structures, the immobilization of macromolecules such as calixarenes and cyclodextrins (CD) with bucket-like structures provides new possibilities for engineered surface-molecule systems. The practical use of any molecular system depends on the availability of a universal procedure for immobilizing molecules with torus-like structures on various surfaces while maintaining identical operating parameters. There are currently several steps, including toxic solvent-based approaches using modified β-CD to covalently attach to surfaces with multistep reactions.

Interphase stabilized electrospun SnO fibers as alloy anode via restricted cycling for Li-ion capacitors with high energy and wide temperature operation.

The second-generation supercapacitor comprises the hybridized energy storage mechanism of Lithium-ion batteries and electrical double-layer capacitors, i.e, Lithium-ion capacitors (LICs). The electrospun SnO nanofibers are synthesized by a simple electrospinning technique and are directly used as anode material for LICs with activated carbon (AC) as a cathode.

Influence of monomers involved in the fabrication of a novel PES based nanofiltration thin-film composite membrane and its performance in the treatment of common effluent (CETP) textile industrial wastewater.

Objective: In this article, monomers (tannic acid (TA) and m- phenylenediamine (MPD)) were used in the fabrication of a novel PES based thin-film composite nanofiltration (TFC-NF) membrane for the treatment of a common effluent treatment plant (CETP) of textile industrial wastewater.

Membrane Synthesis: PES support sheets and TFC layers were fabricated via non-solvent induced phase inversion and in-situ interfacial polymerization (IP) process. The ultra-thin active layer was synthesized via the IP process with monomers such as tannic acid (TA) and m- phenylenediamine (MPD).

Highly Stable Bonding of Thiol Monolayers to Hydrogen-Terminated Si via Supercritical Carbon Dioxide: Toward a Super Hydrophobic and Bioresistant Surface.

Oxide-free silicon chemistry has been widely studied using wet-chemistry methods, but for emerging applications such as molecular electronics on silicon, nanowire-based sensors, and biochips, these methods may not be suitable as they can give rise to defects due to surface contamination, residual solvents, which in turn can affect the grafted monolayer devices for practical applications. Therefore, there is a need for a cleaner, reproducible, scalable, and environmentally benign monolayer grafting process. In this work, monolayers of alkylthiols were deposited on oxide-free semiconductor surfaces using supercritical carbon dioxide (SCCO2) as a carrier fluid owing to its favorable physical properties.

Antibacterial, electrospun nanofibers of novel poly(sulfobetaine) and poly(sulfabetaine)s.

Polymers capable of forming hydration layers have gained increasing attention due to their ability to form environmentally friendly antifouling surfaces. Zwitterionic polymers are an important class of materials under this category. However, the effectiveness of many zwitterionic polymers for long-term applications is compromised because of their solubility in sea water, poor hydrolytic stability and deteriorating mechanical integrity upon wetting.

Application of Organophosphonic Acids by One-Step Supercritical CO2 on 1D and 2D Semiconductors: Toward Enhanced Electrical and Sensing Performances.

Formation of dense monolayers with proven atmospheric stability using simple fabrication conditions remains a major challenge for potential applications such as (bio)sensors, solar cells, surfaces for growth of biological cells, and molecular, organic, and plastic electronics. Here, we demonstrate a single-step modification of organophosphonic acids (OPA) on 1D and 2D structures using supercritical carbon dioxide (SCCO2) as a processing medium, with high stability and significantly shorter processing times than those obtained by the conventional physisorption-chemisorption method (2.5 h vs 48-60 h).

Cellulose Acetate-Poly(N-isopropylacrylamide)-Based Functional Surfaces with Temperature-Triggered Switchable Wettability.

Temperature-triggered switchable nanofibrous membranes are successfully fabricated from a mixture of cellulose acetate (CA) and poly(N-isopropylacrylamide) (PNIPAM) by employing a single-step direct electrospinning process. These hybrid CA-PNIPAM membranes demonstrate the ability to switch between two wetting states viz. superhydrophilic to highly hydrophobic states upon increasing the temperature.

Ultralong Durability of Porous α-FeO Nanofibers in Practical Li-Ion Configuration with LiMnO Cathode.

display an exceptional cycleability when it is paired with commercial LiMnO cathode in full-cell assembly. The performance of such α-FeO nanofibers is mainly due to the presence of unique morphology with porous structure, appropriate mass balance, and working potential. Also, synthesis technique cannot be ruled out for the performance.

Deposition of zwitterionic polymer brushes in a dense gas medium.

Poly(sulfobetaine methacrylate) (PSBMA) films known for their resistance to nonspecific protein adsorption, cell/bacterial adhesion and biofilm formation were produced by surface initiated polymerization on a silicon surface via a batch reaction system in CO2 expanded liquid (CO2-EL) medium. Atom transfer radical polymerization (ATRP) was carried out using 2,2'-bipyridyl as ligand and CuBr as a catalyst in water/methanol mixture with trichloro[4-(chloromethyl)phenyl]silane (CMPS) used as the initiating species. The films were grown in the CO2-EL environment at a range of conditions and thickness up to 10nm.

Electrospun nanofibers: a prospective electro-active material for constructing high performance Li-ion batteries.

In the present review, we describe the development of a high energy density LIB fabricated with all 1D nanofibers as the anode and cathode, as well as a separator-cum-electrolyte prepared by an electrospinning technique without compromising the power capability and cycle life. Such a unique assembly certainly enables realizing the advantages of using 1D nanostructures in practical LIBs, irrespective of the anode or cathode in the presence of gelled polyvinylidene fluoride-co-hexafluoropropylene as the separator-cum-electrolyte. Outstanding cycling profiles with high power densities were noted for all the configurations evaluated.

Exceptional performance of a high voltage spinel LiNi0.5Mn1.5O4 cathode in all one dimensional architectures with an anatase TiO2 anode by electrospinning.

We report for the first time the synthesis and extraordinary performance of a high voltage spinel LiNi(0.5)Mn(1.5)O4 fiber cathode in all one dimensional (1D) architecture.

Unveiling TiNb2 O7 as an insertion anode for lithium ion capacitors with high energy and power density.

This is the first report of the utilization of TiNb2 O7 as an insertion-type anode in a lithium-ion hybrid electrochemical capacitor (Li-HEC) along with an activated carbon (AC) counter electrode derived from a coconut shell. A simple and scalable electrospinning technique is adopted to prepare one-dimensional TiNb2 O7 nanofibers that can be characterized by XRD with Rietveld refinement, SEM, and TEM. The lithium insertion properties of such electrospun TiNb2 O7 are evaluated in the half-cell configuration (Li/TiNb2 O7 ) and it is found that the reversible intercalation of lithium (≈3.

Exceptional performance of TiNb₂O₇ anode in all one-dimensional architecture by electrospinning.

We report the extraordinary performance of an Li-ion battery (full-cell) constructed from one-dimensional nanostructured materials, i.e. nanofibers as cathode, anode, and separator-cum-electrolyte, by scalable electrospinning.

Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors.

In this manuscript, a dramatic increase in the energy density of ~ 69 Wh kg⁻¹ and an extraordinary cycleability ~ 2000 cycles of the Li-ion hybrid electrochemical capacitors (Li-HEC) is achieved by employing tailored activated carbon (AC) of ~ 60% mesoporosity derived from coconut shells (CS). The AC is obtained by both physical and chemical hydrothermal carbonization activation process, and compared to the commercial AC powders (CAC) in terms of the supercapacitance performance in single electrode configuration vs. Li.

Morphologically robust NiFe2O4 nanofibers as high capacity Li-ion battery anode material.

In this work, the electrochemical performance of NiFe2O4 nanofibers synthesized by an electrospinning approach have been discussed in detail. Lithium storage properties of nanofibers are evaluated and compared with NiFe2O4 nanoparticles by galvanostatic cycling and cyclic voltammetry studies, both in half-cell configurations. Nanofibers exhibit a higher charge-storage capacity of 1000 mAh g(-1) even after 100 cycles with high Coulmbic efficiency of 100% between 10 and 100 cycles.

A novel strategy to construct high performance lithium-ion cells using one dimensional electrospun nanofibers, electrodes and separators.

We successfully demonstrated the performance of novel, one-dimensional electrospun nanofibers as cathode, anode and separator-cum-electrolyte in full-cell Li-ion configuration. The cathode, LiMn2O4 delivered excellent cycle life over 800 cycles at current density of 150 mA g(-1) with capacity retention of ~93% in half-cell assembly (Li/LiMn2O4). Under the same current rate, the anode, anatase phase TiO2, rendered ~77% initial reversible capacity after 500 cycles in half-cell configuration (Li/TiO2).

Electrospun ZnO nanowire plantations in the electron transport layer for high-efficiency inverted organic solar cells.

Inverted bulk heterojunction organic solar cells having device structure ITO/ZnO/poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C61 butyric acid methyl ester (PCBM) /MoO3/Ag were fabricated with high photoelectric conversion efficiency and stability. Three types of devices were developed with varying electron transporting layer (ETL) ZnO architecture. The ETL in the first type was a sol-gel-derived particulate film of ZnO, which in the second and third type contained additional ZnO nanowires of varying concentrations.

Synthesis of porous LiMn2O4 hollow nanofibers by electrospinning with extraordinary lithium storage properties.

We report the extraordinary lithium storage performance of porous LiMn2O4 hollow nanofibers synthesized by electrospinning technique. The electrospun LiMn2O4 hollow nanofibers retained 87% of initial reversible capacity after 1250 cycles at the 1 C rate. Further, excellent cycling profiles at 55 °C and cubic spinel to tetragonal phase transformation are also noted.

Stable Organic Monolayers on Oxide-Free Silicon/Germanium in a Supercritical Medium: A New Route to Molecular Electronics.

Oxide-free Si and Ge surfaces have been passivated and modified with organic molecules by forming covalent bonds between the surfaces and reactive end groups of linear alkanes and aromatic species using single-step deposition in supercritical carbon dioxide (SCCO2). The process is suitable for large-scale manufacturing due to short processing times, simplicity, and high resistance to oxidation. It also allows the formation of monolayers with varying reactive terminal groups, thus enabling formation of nanostructures engineered at the molecular level.

Polythiophene-gold nanoparticle hybrid systems: Langmuir-Blodgett assembly of nanostructured films.

In this work, we demonstrate a simple method of synthesizing nanoscale polythiophene-gold nanoparticle (AuNP) hybrid systems assembled by the Langmuir-Blodgett (LB) method. Regio-regular poly(3-(2-methoxyethoxy)ethoxymethyl)thiophene-2,5-diyl (PMEEMT) and poly(3-dodecylthiophene) (PDDT) were employed as the polymeric constituents. The presence of PDDT improved the amphiphilicity of PMEEMT by addressing the phase separation that occurred due to convective hydrodynamic instability on the substrate.

In situ application of polyelectrolytes in zinc oxide nanorod synthesis: understanding the effects on the structural and optical characteristics.

We report a facile and simple means of synthesizing a macroscopic array of ZnO nanorods with high feature densities using a modified hydrothermal approach that involves the in situ introduction of polyelectrolyte. The ZnO nanorod arrays with heights of 1.5 μm and diameters of 350 nm were consistently reproducible and were bestowed with the advantage of in situ process tunability offered by employing polyethylenimine (PEI) as a surface modifying agent.