There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

A comprehensive review on biosorption of heavy metals by algal biomass: Materials, performances, chemistry, and modeling simulation tools

Organic thin film transistor (OTFT) based device modeling and circuit application is a rapidly emerging research area. Taking cognizance of this fact, our paper reviews various basic to advanced OTFT structures, their performance parameters, materials of individual OTFT layers, their molecular structures, OTFT charge transport phenomena, and fabrication techniques. The performance of p- and n-type conducting polymer and small molecule organic semiconductors are reviewed primarily in terms of field effect mobility, current on/off ratio, and operating voltage for various OTFT structures. Moreover, different organic/inorganic materials for realizing the dielectric layer, electrodes, and the substrate in an OTFT are analyzed. Some of the compact models that are essential for predicting and optimizing the device performance are described that takes into account the mobility enhancement factor and channel length modulation. A detailed study of the single gate, dual gate, vertical channel, and cylindrical gate O...

Organic Thin Film Transistors: Structures, Models, Materials, Fabrication, and Applications: A Review

Metal phthalocyanines (MPcs) are versatile conjugated macrocycles that have attracted a great deal of interest as active components in modern organic electronic devices. In particular, the charge transport properties of MPcs, their chemical stability, and their synthetic versatility make them ideal candidate materials for use in organic thin-film transistors (OTFTs). This article reviews recent progress in both the material design and device engineering of MPc-based OTFTs, including the introduction of solubilizing groups on the MPcs and the surface modification of substrates to induce favorable MPc self-assembly. Finally, a discussion on emerging niche applications based on MPc OTFTs will be explored, in addition to a perspective and outlook on these promising materials in OTFTs. The scope of this review is focused primarily on the advances made in the field of MPc-based OTFTs since 2008.

Phthalocyanine-Based Organic Thin-Film Transistors: A Review of Recent Advances

Electronics and Optoelectronics Junliang Yang,*,†,‡ Donghang Yan, and Tim S. Jones †Institute of Super-microstructure and Ultrafast Process in Advanced Materials and ‡Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083, People’s Republic of China State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, People’s Republic of China Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom

Molecular template growth and its applications in organic electronics and optoelectronics.

Novel alginate hybrid beads were prepared by doping with silica (abbreviated as ALG/SiO2), and their adsorption behavior toward rare earths(III) had been investigated. For the whole lanthanides, it exhibits a distinct “tetrad effect” with increasing atomic number. Taking Nd as an example, the effects of the pH, adsorption kinetics, isotherms, and regeneration of adsorbents had been studied systematically. Doped SiO2 can enhance the mechanical strength of the beads, and the hybrid adsorbents show no observable swelling during the adsorption process. It is interesting to note that NdIII adsorption can be improved about 0.1 mmol/g after the first cycle and shows no apparent decline until the 12th cycle. Finally, it can be concluded that ALG/SiO2 is superior to the other hybrid alginate adsorbents for the adsorption of rare earths.

Adsorption Properties toward Trivalent Rare Earths by Alginate Beads Doping with Silica

Organic template-free synthesis of ZSM-5 zeolite from coal-series kaolinite

Nano-sized ZSM-5 aggregates have been rapidly synthesized from leached metakaolin by solid-like state conversion. The influence of synthesis conditions such as TPA+/SiO2, NaOH/SiO2 and SiO2/Al2O3 molar ratios on the final products was investigated. The properties of nano-sized ZSM-5 aggregates were characterized by XRD, SEM, HRTEM, 29Si and 27Al MAS NMR, NH3-TPD, TG, N2 adsorption–desorption and particle size analysis. The results clearly showed that nano-sized ZSM-5 aggregates could be obtained within 2 h via solid-like state conversion. SEM revealed that the obtained ZSM-5 aggregates were irregular spheres that consisted of nano-sized crystallites with 30–50 nm. The crystallization process indicated that the size of flaky raw materials gradually decreased and formed nano-sized particles as time prolonged. Therefore, the transformation mechanism followed the solution mediated mechanism, though only a little water was contained in the system. Compared with the conventional hydrothermal route, the solid-like state conversion not only significantly shortened the crystallization time, but also totally avoided the emission of waste liquids. In addition, for the methanol dehydration reaction, the nano-sized ZSM-5 aggregates obtained by this method showed much better catalytic performance, C2–C4 olefin selectivity and longer lifetime to endure coke deposition than the sample obtained by the hydrothermal route.

A fast route for synthesizing nano-sized ZSM-5 aggregates

Two ladder-type conjugated molecules, i.e., 2,2′-(2,7-dihexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-4,9-diylidene) dimalononitrile (1) and 2,7-dihexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-4,9-dione (2) were synthesized in high yields, and their electrochemical properties, single crystal structures, thin-film morphology and field-effect mobility were investigated. The LUMO/HOMO levels of 1 and 2 are −4.07/−6.00 and −3.62/−5.82 eV, respectively, as estimated from the thin-film cyclic voltammetry measurements. In the single crystals, both compounds exhibit one dimensional π–π stacking of molecules, and 1 shows the larger π-electron overlap between the neighboring molecules than 2, along with interdigitation of alkyl chains. Thin-film X-ray diffraction (XRD) and atomic force microscopy (AFM) characterizations indicate that 1 can form films with higher molecular order than 2. Field-effect electron mobility up to 0.33 cm2 V−1 s−1 in air for 1 and hole mobility up to 0.05 cm2 V−1 s−1 for 2 have been demonstrated with the top-contact organic thin-film transistor (OTFT) device structure. Electron mobility of 1 is among the highest value for n-type organic semiconductors.

Feng Pan

Papers

Adsorption Properties toward Trivalent Rare Earths by Alginate Beads Doping with Silica

Organic template-free synthesis of ZSM-5 zeolite from coal-series kaolinite

A fast route for synthesizing nano-sized ZSM-5 aggregates

A feasibly synthesized ladder-type conjugated molecule as the novel high mobility n-type organic semiconductor

Synthesis and crystallization kinetics of ZSM-5 without organic template from coal-series kaolinite