When dating documents by radiocarbon (14C), what we typically measure is the concentration of the support (e.g. paper, parchment, or papyrus). This can however lead to a possible misinterpretation of results because the support may be older than the writing itself. To minimize such a possible ambiguity, the ideal approach would be direct dating of the ink or color (if organic). Here we propose a feasibility study to date carbon-based black inks when deposited on papyrus, one of the most widespread writing supports used in the past. We prepared test samples, using a commercial papyrus and a homemade black ink, obtained combining modern charcoal fragments and Arabic gum. Even though the ink binder might have represented the best candidate to be dated, we verified by FTIR that the molecular composition of its soluble fraction is very similar to papyrus extractives, thus identifying the residual charcoals recovered after extraction as the most suitable material for the measurement. Enough charcoal material was extracted from the test samples and processed using our new setup optimized for microgram-size samples. The overall experimental procedure was found to be reproducible, and measured 14C concentrations were coherent with the data obtained from larger samples and raw materials.

Bottom-up assembly of nanomaterials using solution-processed methods is ideally suited for use in fabrication of large-area optoelectronic devices. Tailorable visible and near-infrared absorption in shaped nanostructured noble metals is strongly influenced by localized plasmon resonance effects. Obtaining sharp and selective absorption with solution-processed methods is a challenge and requires suitable control on the growth kinetics, which ultimately results in appropriate size and morphology of the final product. In this work, a photo-assisted multigenerational growth process for synthesis of silver nanotriangle ink with narrow linewidth absorbance is developed. This technique combines photochemical and seed-mediated growth approaches. The resulting ink exhibits a sharp absorption at 700 nm with full width at half maximum of ∼170 nm, verified by absorption as well as dynamic light scattering, transmission electron microscopy, and field emission scanning electron microscopy measurements. Numerical modeling using finite-difference time-domain calculations yields a close match with observed absorption and is used to examine electric field distribution and enhancement factor resonating at 720 nm. The synthesis technique is potentially useable for production of highly selective absorbers in solution phase.

The necessity of studying cultural heritage through non-invasive and non-destructive techniques has led to significant advances in the last decade. One of the most recent advancements in this theme in Mexico is the portable X-ray system SANDRA, which was used to study three manuscripts directly related to the history of “San Nicolás Coatepec”, Mexico. X-ray fluorescence was chosen as the suitable technique because it can provide a fast qualitative and quantitative multielemental high sensitivity analysis. The documents were examined globally, using imaging techniques with UV and IR lighting. This research evinced a change in the composition and evolution of writing materials (inks and pigments) and provided information concerning historical use of the documents and its actual legal value as a property document. It also stressed the need of spanning these results to an extensive research attaining other regions of Mexico, in order to fully understand the Mexican documents particularities, aging and deterioration. This, in turn, will provide not only historical material information but also an invaluable scoop to understand deterioration and conservation issues.