Daniel A. Foucher

Bio: Daniel A. Foucher is an academic researcher from Xerox. The author has contributed to research in topics: Ring-opening polymerization & Polymerization. The author has an hindex of 23, co-authored 63 publications receiving 2516 citations. Previous affiliations of Daniel A. Foucher include University of Toronto.

Surfactant free toner processes

Abstract: A process for the preparation of toner comprising mixing an amine, an emulsion latex containing sulfonated polyester resin, and a colorant dispersion, heating the resulting mixture, and optionally cooling.

Synthesis, characterization, glass transition behavior, and the electronic structure of high-molecular-weight, symmetrically substituted poly(ferrocenylsilanes) with alkyl or aryl side groups

Abstract: A series of high molecular weight, symmetrically substituted poly(ferrocenylsilanes) [Fe(η-C 5 H 4 ) 2 (SiR 2 )] n (2a-e: a, R=Me; b, R=Et; c, R=Bu; d, R=Her; e, R=Ph) have been prepared via the thermal ring-opening polymerization of the corresponding strained cyclic ferrocenylsilane monomers Fe(η-C 5 H 4 ) 2 (SiR 2 ). Polymer 2e was found to be insoluble in common organic solvents. The solution behavior of 2c was investigated and yielded an absolute value of M w = 2.29x10 5 and a second virial coefficient A 2 = 1.3x10 -4 mol cm 2 g -2 in THF at 20°C. T g s of the polymers varied with the substituents present and were found in the range of -26°C (for 2d) to +33°C (for 2a). No evidence for melting transitions was detected for the polymer samples studied

Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Abstract: Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers. (2) Special microstructural features of PDCs. (3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines. (4) Processing strategies to fabricate ceramic components from preceramic polymers. (5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research Society. Most of the reviews available on PDCs are either not up to date or deal with only a subset of preceramic polymers and ceramics (e.g., silazanes to produce SiCN-based ceramics). Thus, this review is focused on a large number of novel data and developments, and contains materials from the literature but also from sources that are not widely available.

Acetylenic polymers: syntheses, structures, and functions.

Abstract: Department of Chemistry, William Mong Institute of Nano Science and Technology, Bioengineering Graduate Program, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Key Laboratory of Macromolecular Synthesis and Functionalization of the Ministry of Education, Institute of Biomedical Macromolecules, Zhejiang University, Hangzhou 310027, China

From Condensed Lanthanide Coordination Solids to Microporous Frameworks Having Accessible Metal Sites

Abstract: The combination of terbium nitrate and 1,4-benzenedicarboxylic acid (H2BDC) in the presence of triethylamine yields the compound Tb2(BDC)3·(H2O)4, which has an extended nonporous structure constructed from copolymerized BDC and Tb(III) units. The multidentate functionality of BDC and the tendency of Tb to have a high coordination number has allowed water to act as a terminal ligand to Tb in the structure. Upon thermally liberating the water ligands, a microporous material, Tb2(BDC)3, is achieved, which has extended 1-D channels and the same framework structure as that of the as-synthesized solid as evidenced by XRPD. Water sorption isotherm data proves that Tb2(BDC)3 has permanent microporosity, and points to the presence of accessible metal sites within the pores, which also allows the sorption of ammonia to give Tb2(BDC)3·(NH3)4. Luminescence lifetime measurements confirm that resorbed water and sorbed ammonia are bound to Tb and that they give distinctly different decay constants.