A new FTIR method for estimating the firing temperature of ceramic bronze-casting moulds from early China

Abstract

Intricate ceramic bronze-casting moulds are among the most significant archaeological remains found at Bronze Age metallurgical workshops in China. Firing temperature was presumably one of the most important technical factors in mould making. However, it has proven difficult to determine the firing temperatures of excavated moulds using existing analytical methods. This study establishes an innovative new method for using Fourier-transform infrared spectroscopy (FTIR) to estimate the firing temperature of clay-containing remains. The method is based on the finding that the infrared absorptivity of fired clay minerals, measured at the Si–O–Si stretching resonance band, is negatively correlated with firing temperature. Moulds and mould cores dating to the Early Shang period (sixteenth to fourteenth century BCE) are found to have been fired at extremely low temperatures—as low as 200–300 °C in many instances. These results provide critical new data for understanding the metallurgical technology of ancient China.

The Fourier transform infrared spectroscopy (FTIR) analysis for the clay mineralogy studies in a clastic reservoir

“…The FTIR analysis has several advantages over the XRD including: (i) the preparation of powder samples is quite easy and fast (KBr pellets normally take 5-8 min to be ready); (ii) the collection of spectrum is fast (it takes almost 1-2 min), (iii) only small amount of samples (about 0.3 g) are required; (iv) additional treatments of samples are not required, and (v) it is cheap compared to the XRD method (Madejová & Komadel 2001;Ji et al 2009;Pálková et al 2020). The spectral absorption characteristics in the IR spectra are qualitatively related to the variations in the constituent minerals and can be used for investigating the crystalline structure, type of bonding, and some chemical information on the clay minerals (Madejová, 2003;Du et al 2010;Yan et al 2021). The Fourier transforms of IR spectra are being increasingly used to aid the clay mineral identification (Madejová, 2003;Vaculíková & Plevová, 2005;Nayak & Singh 2007;Worasith et al 2011;Repacholi 1994;Djomgoue & Njopwouo 2013;Chen et al 2020;El-Shater et al 2021).…”

Enhancing Methotrexate Delivery in the Brain by Mesoporous Silica Nanoparticles Functionalized with Cell-Penetrating Peptide using in Vivo and ex Vivo Monitoring

“…46 The medium intensity peak at 474 cm −1 was attributed to the bending vibrations of the Si−O−Si groups. 47 These results indicated successful synthesis of the silica-based materials. Complete elimination of the surfactant CTAB from the MSNs was confirmed by the disappearance of the C−H peak (CH 2 symmetric 48 and asymmetric stretches 49 ) at 2800−3000 cm −1 .…”

Sol–gel synthesis of alumina gel@zeolite X nanocomposites for high performance water defluoridation: batch and column adsorption study

“…The Si–O–Si stretching and bending vibrations are located at 990 and 460 cm −1 , respectively; whereas the Si–O–Al bending vibration is confirmed at 580 cm −1 . 29 The shifting of the stretching vibration of Si–O–Si to a lower wavenumber is attributed to a decrease in bond strength with internal hydrogen bonding as Si–O⋯HO–Si and Si–O⋯HO–Al. 24 The absorption bands at 662 and 735 cm −1 are the signature of Si–O/Al–O S4R symmetric bending and stretching vibrations of zeolite X, respectively.…”