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A hierarchically porous polymer (HPP) consisting of micropores (∼1 nm) within a 3D continuous mesoporous wall (∼15 nm) was used to support well-defined Pt nanoparticles (2 nm in diameter) as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction in the liquid phase. The ligand-capped nanoparticles were loaded into the polymer and treated with plasma to expose the active surface. The dual porosity was essential: the block polymer-templated mesopores provided the reactants facile access to the nanoparticle center, which was firmly immobilized by the microporous surface. Compared to inorganic mesoporous silica supports, which are intrinsically susceptible to basic hydrolysis, the Pt-HPP featured higher activity for all halide leaving groups, even in green solvents, as well as excellent recyclability. Only 5% decrease in activity was observed after 10 cycles. Pt-HPP was one of the most active heterogeneous catalysts for aryl chloride substrates compared to literature Pt or Pd examples. [ABSTRACT FROM AUTHOR]

An efficient self-supported Cu(II)Bi(III) bimetallic catalyst with a layered structure was designed and developed. By careful characterization of the as-prepared material, the host structure was identified to exhibit a Sillen-type bismutite framework, with copper(II) ions being loaded as guests. The heterogeneous catalyst enabled C-N and C-S arylations under mild reaction conditions and with high chemoselectivities, thus furnishing valuable phenothiazines via heterocyclization with wide substrate tolerance. As corroborated by detailed catalytic studies, the cooperative, bifunctional catalyst, bearing Lewis acid sites along with copper(II) catalytic sites, facilitated an intriguing concerted C-N/C-S heterocyclization mechanism. The heterogeneous nature of the catalytic reactions was verified experimentally. Importantly, the catalyst was successfully recycled and reused multiple times, persevering its original structural order as well as its initial activity.

Although gilt silver threads were widely used for decorating historical textiles, their manufacturing techniques have been elusive for centuries. Contemporary written sources give only limited, sometimes ambiguous information, and detailed cross-sectional study of the microscale soft noble metal objects has been hindered by sample preparation. In this work, to give a thorough characterization of historical gilt silver threads, nano- and microscale textural, chemical, and structural data on cross sections, prepared by focused ion beam milling, were collected, using various electron-optical methods (high-resolution scanning electron microscopy (SEM), wavelength-dispersive electron probe microanalysis (EPMA), electron backscattered diffraction (EBSD) combined with energy-dispersive electron probe microanalysis (EDX), transmission electron microscopy (TEM) combined with EDX, and micro-Raman spectroscopy. The thickness of the gold coating varied between 70-400 nm. Data reveal nano- and microscale metallurgy-related, gilding-related and corrosion-related inhomogeneities in the silver base. These inhomogeneities account for the limitations of surface analysis when tracking gilding methods of historical metal threads, and explain why chemical information has to be connected to 3D texture on submicrometre scale. The geometry and chemical composition (lack of mercury, copper) of the gold/silver interface prove that the ancient gilding technology was diffusion bonding. The observed differences in the copper content of the silver base of the different thread types suggest intentional technological choice. Among the examined textiles of different ages (13th-17th centuries) and provenances narrow technological variation has been found.

Development of novel biodegradable and biocompatible scaffold materials with optimal characteristics is important for both preclinical and clinical applications. The aim of the present study was to analyze the biodegradability of poly(aspartic acid)-based hydrogels, and to test their usability as scaffolds for MG-63 osteoblast-like cells. Poly(aspartic acid) was fabricated from poly(succinimide) and hydrogels were prepared using natural amines as cross-linkers (diaminobutane and cystamine). Disulfide bridges were cleaved to thiol groups and the polymer backbone was further modified with RGD sequence. Biodegradability of the hydrogels was evaluated by experiments on the base of enzymes and cell culture medium. Poly(aspartic acid) hydrogels possessing only disulfide bridges as cross-links proved to be degradable by collagenase I. The MG-63 cells showed healthy, fibroblast-like morphology on the double cross-linked and RGD modified hydrogels. Thiolated poly(aspartic acid) based hydrogels provide ideal conditions for adhesion, survival, proliferation, and migration of osteoblast-like cells. The highest viability was found on the thiolated PASP gels while the RGD motif had influence on compacted cluster formation of the cells. These biodegradable and biocompatible poly(aspartic acid)-based hydrogels are promising scaffolds for cell cultivation.