Intercalation of large organocations into 2:1 clay minerals may be hampered by two problems: on one hand, the solubility of organocations in water is limited and the resulting high selectivity for adsorption in the polar solvent may lead to non-equilibrium structures. On the other hand, the large expansion of the interlayer space will slow down kinetics of ion exchange considerably. The best workaround for these obstacles is to suspend the clay minerals in mixtures of water with more hydrophobic organic solvents that nevertheless trigger a considerable expansion of the interlayer space by swelling. This in turn fosters ion exchange. The current study, therefore, revisited pioneering work by Bradley (1945) and investigated the swelling behavior of synthetic sodium hectorite (Na-hec) as a function of the composition of the swelling solvent, a mixture of acetonitrile and water. Up to a maximum acetonitrile content of 65 vol.%, delamination by osmotic swelling occurred. At even higher acetonitrile concentrations, swelling was limited to the crystalline swelling regime where a step-like adjustment of the d value was observed. Several mixtures were identified yielding a well defined and uniform interlayer height as evidenced by rational 00l-series with the d spacing decreasing with increasing acetonitrile content. Surprisingly, for a specific acetonitrile:water ratio even an ordered interstratification of two strictly alternating interlayer heights with distinctly different solvent compositions was observed.

ObjectiveEmergency department length of stay (EDLOS) is linked to crowding and patient outcomes whereas worse prognosis in low socioeconomic status remains poorly understood. We studied whether income was associated with ED process times among patients with chest pain.MethodsThis was a registry‐based cohort study on 124,980 patients arriving at 14 Swedish EDs between 2015 and 2019 with chest pain as their chief complaint. Individual‐level sociodemographic and clinical data were linked from multiple national registries. The associations between disposable income quintiles, whether the time to physician assessment exceeded triage priority recommendations as well as EDLOS were evaluated using crude and multivariable regression models adjusted for age, gender, sociodemographic variables, and ED‐management circumstances.ResultsPatients with the lowest income were more likely to be assessed by physician later than triage recommendations (crude odds ratio [OR] 1.25 (95% confidence interval [CI] 1.20–1.29) and have an EDLOS exceeding 6 h (crude OR 1.22 (95% CI 1.17–1.27). Among patients subsequently diagnosed with major adverse cardiac events, patients with the lowest income were more likely to be assessed by a physician later than triage recommendations, crude OR 1.19 (95% CI 1.02–1.40). In the fully adjusted model, the average EDLOS was 13 min (5.6%) longer among patients in the lowest income quintile, 4:11 [h:min], (95% CI 4:08–4:13), compared to patients in the highest income quintile, 3:58 (95% CI 3:56–4:00).ConclusionsAmong ED chest pain patients, low income was associated with longer time to physician than recommended by triage and longer EDLOS. Longer process times may have a negative impact due to crowding in the ED and delay diagnosis and timely treatment of the individual patient.