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

Hydrogels for tissue engineering.

https://yunus.hacettepe.edu.tr/~damlacetin/kmu407/index_dosyalar/4.%20makale.pdf

Biodegradable polymers as biomaterials

Hydrogels in pharmaceutical formulations.

Lithium (Li) metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1), low density (0.59 g cm−3) and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode). Unfortunately, uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping inherent in these batteries have prevented their practical applications over the past 40 years. With the emergence of post-Li-ion batteries, safe and efficient operation of Li metal anodes has become an enabling technology which may determine the fate of several promising candidates for the next generation energy storage systems, including rechargeable Li–air batteries, Li–S batteries, and Li metal batteries which utilize intercalation compounds as cathodes. In this paper, various factors that affect the morphology and Coulombic efficiency of Li metal anodes have been analyzed. Technologies utilized to characterize the morphology of Li deposition and the results obtained by modelling of Li dendrite growth have also been reviewed. Finally, recent development and urgent need in this field are discussed.

Lithium metal anodes for rechargeable batteries

Ferrocenylphosphazenes have been prepared by the reactions of lithioferrocene with hexafluorocyclo-triphosphazene or octafluorocyclotetraphosphazene, and their structures were determined by spectroscopic and crystallographic techniques.

Ferrocene-bound cyclophosphazenes. X-Ray crystal structure of N3P3F5(C5H4FeC5H5)

Crystalline transitions and related physical properties of poly(dichlorophosphazene)

This work is an investigation of the influence of bulky fluoroalkoxy side groups on the properties of polyphosphazenes. A new series of mixed-substituent high polymeric poly(fluoroalkoxyphosphazenes) containing trifluoroethoxy and branched fluoroalkoxy side groups was synthesized and characterized by NMR and GPC methods. These polymers contained 19–29 mol % of dibranched hexafluoropropoxy groups or 4 mol % of tribranched tert-perfluorobutoxy groups which serve as regio-irregularities to reduce the macromolecular microcrystallinity. The structure–property correlations of the polymers were then analyzed and interpreted by several techniques: specifically by the thermal behavior by DSC and TGA methods, the crystallinity by wide-angle X-ray diffraction, and the surface hydrophobicity/oleophobicity by contact angle measurements. Ultraviolet cross-linkable elastomers were prepared from the new polymers through the incorporation of 3 mol % of 2-allylphenoxy and photoirradiation. The mechanical properties and the...

New Mixed-Substituent Fluorophosphazene High Polymers and Small Molecule Cyclophosphazene Models: Synthesis, Characterization, and Structure Property Correlations

Langmuir−Adam trough studies have been carried out to study the behavior of seven cyclic and linear short-chain small-molecule phosphazenes and four high polymers at air−water interfaces. The small-molecule compounds are models for a variety of phosphazene high polymers. The influence of phenoxy, 1,2-benzenedioxy, OCH2CF3, NH2, NEt2, NBu2, and OCH2CH2CH2CH2OCH3 side groups was studied. The air−water interface behavior of the small molecules depended on (a) the cyclic or linear skeletal structure and (b) the types of side groups linked to the ring or chain. The utilization of these results for understanding the behavior of phosphazene high polymers at air−water interfaces is discussed.

Harry R. Allcock

Papers

Ferrocene-bound cyclophosphazenes. X-Ray crystal structure of N3P3F5(C5H4FeC5H5)

Crystalline transitions and related physical properties of poly(dichlorophosphazene)

New Mixed-Substituent Fluorophosphazene High Polymers and Small Molecule Cyclophosphazene Models: Synthesis, Characterization, and Structure Property Correlations

Langmuir−Adam Trough Studies of Hydrophobicity, Hydrophilicity, and Amphilicity in Small-Molecule and High-Polymeric Phosphazenes

A bis(benzene)chromium-bridged cyclophosphazene: x-ray structure analysis of N3P3F4(.eta.-C6H5)2Cr