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

The first example of bis(indolyl)methane based hyperbranched polyurethanes: Synthesis, solar cell application and anti-bacterial and anti-oxidant properties

In this study, a modified dendritic functional monomer (named DA) consisting of 1,3-propanediamine as the initiated core was prepared and utilized to react with acrylamide (AM), acrylate (AA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) to synthesize a water-soluble hyperbranched copolymer (noted HPDA) for low-to-moderate permeability reservoirs through a redox free radical polymerization strategy. The copolymer was characterized by a series of experiments, including IR, 1H NMR, DLS and AFM. It was observed expectedly that the HPDA solution displayed a distinct topological structure in solution, resulting in a smaller mean diameter in comparison to the linear polymer. Furthermore, the rheology performances and anti-shearing properties of HPDA were investigated, which demonstrated that the introduced dendritic structure could endow the polymer with great viscosity retention and excellent elasticity in a relatively high frequency region. Based on the sand packed tube displacement experiment, a favorable matching relationship could be found between the size of the sheared HPDA and the pore throat as the permeability ranged from 500 to 100 mD. Moreover, compared with the linear polymer, AM/AA/AMPS, the sheared HPDA solution of 2000 mg L−1 could significantly increase the efficiency of oil recovery to 21.9% and 17.5% by controlling the displacing phase mobility and constructing an appreciable resistance factor and residual resistance factor in the 500 and 260 mD porous media.

A water-soluble hyperbranched copolymer based on a dendritic structure for low-to-moderate permeability reservoirs

Stilbenoid dendrimers with phenothiazine as a surface group were synthesized in good yields by the Heck and Horner–Wadsworth–Emmons coupling reaction and characterized by spectral and analytical data. Various core units such as trimethylbenzene, pyridine, and triphenylamine with phenothiazine as the surface unit were employed for the synthesis of dendrimers. The photophysical properties of the dendrimers reveal that as the generation increases the light absorption ability also increases. Furthermore, as the generation increases the absorption maxima show a hypsochromic shift for the n–π* transition and a bathochromic shift for the π–π* transition. However, the fluorescence emission in general increases as the dendrimer generation increases. When the synthesized stilbenoid dendrimers are utilized as an additive in the redox couple (I−/I3−) of a Dye Sensitized Solar Cell (DSSC), the solar energy conversion efficiency increases with an increase in generation and reaches a maximum of 7.3% with the higher generation dendrimer 10.

Synthesis and application of stilbenoid phenothiazine dendrimers as additives for dye-sensitized solar cells

The First Example of Bisindole‐Based Polyurethane Dendrimers: Synthesis and Performance in DSSC

The use of novel p-chlorophenyl and styrenyl-TEMPO terminated fourth generation (G4) polyurethane dendrimers doped with KI and I2 in conjunction with N3 dye as an efficient polymer electrolyte to improve the efficiency of nanocrystalline TiO2 dye-sensitized solar cell (DSSC) is described. Coordinative interactions and structural changes of these dendritic polymer electrolytes have been characterized by X-ray diffraction (XRD), electrical conductivity and scanning electron microscopic (SEM) studies. The XRD and SEM results confirm the amorphous structure of the electrolytes. The ionic conductivity of doped polyurethane dendrimers was remarkably high and the values were in the range of 1.5 × 10−3 Scm−1 to 1.1 × 10−3 Scm−1 at room temperature. As a consequence, the performance of the devices fabricated with dendrimers were appreciably good compared to that fabricated without dendrimers and in one case the photocurrent, photovoltage, fill factor and energy conversion efficiency achieved were 10.6 mA cm−2, 900 (mV), 0.51 and 8.5%, respectively, under simulated sunlight with AM 1.5 at 50 mW cm−2.

Enhanced performance of a nanocrystalline dye-sensitized solar cell based on polyurethane dendrimers

Protective effect of Date Palm Fruits (Phoenix Dactylifera L.) versus vitamin C against mobile Phone Radiation-induced Pituitary gland damage in rats

Moringa oleifera extract could ameliorate aging-related structural and functional hepatic changes by regulating autophagy signaling pathway

Metabolite Profiling of Date Palm Fruit (Phoenix dactylifera L.) And Its Cytoprotective Effects Versus Vitamin C Against Mobile Phone Radiation-Induced Adrenal Gland Damage In Rats

M. Abdul Rahman

Papers

Enhanced performance of a nanocrystalline dye-sensitized solar cell based on polyurethane dendrimers

Protective effect of Date Palm Fruits (Phoenix Dactylifera L.) versus vitamin C against mobile Phone Radiation-induced Pituitary gland damage in rats

Moringa oleifera extract could ameliorate aging-related structural and functional hepatic changes by regulating autophagy signaling pathway

Metabolite Profiling of Date Palm Fruit (Phoenix dactylifera L.) And Its Cytoprotective Effects Versus Vitamin C Against Mobile Phone Radiation-Induced Adrenal Gland Damage In Rats