Hydrated magnesium carbonates derived from brucite: Structural and vibrational analysis via synchrotron XRD and Raman spectroscopy
Bibliographic record
Abstract
This study explores the formation of hydrated magnesium carbonates (HMCs) cement via the carbonation of brucite [Image 1] using sodium bicarbonate [Image 2] as a carbon source. Employing synchrotron radiation X-ray diffraction (SRXRD) and time-gated Raman spectroscopy (tgRS), we investigate the HMCs formation and their conversion in pure aqueous solution and solutions containing 1 M magnesium acetate (MgAc, Image 3). While previous studies have established the influence of reaction time and MgAc ligands on HMC formation, we present deeper insights into the role of sodium (Na) and MgAc in this system. Notably, eitelite [Image 4], a Na-containing carbonated phase, was detected after 7 and 28 days of carbonation in water [Image 5] but was absent when MgAc was present in the solution, revealing a key role of MgAc on phase selection. Additionally, acetate actively involves into the formation of an organo-modified HMC, identified as acetate-containing giorgiosite (ACG, Image 6), form through the conversion of nesquehonite [Image 7]. This phase was detected just 1 day into the reaction - significantly earlier than previously reported crystallization times. As the reaction time progressed, nesquehonite gradually converted into ACG in the presence of MgAc, and into eitelite in the absence of MgAc. These findings underscore the complementary strengths of SRXRD and tgRS in elucidating HMC formation and conversion pathways - SRXRD can tracks early-stage carbonation products, while tgRS provides molecular-level insights. Together, these techniques not only validate prior studies but also reveal additional mechanistic details governing HMC cement formation.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".