Quenching of lamellar ordering in an n-alkane embedded in nanopores

We present an X-ray diffraction study of the normale alkane nonadecane C_{19}H_{40} embedded in nanoporous Vycor glass. The confined molecular crystal accomplishes a close-packed structure by alignment of the rod-like molecules parallel to the pore axis while sacrificing one basic principle known from the bulk state, i.e. the lamellar ordering of the molecules. Despite this disorder, the phase transitions observed in the confined solid mimic the phase behavior of the 3D unconfined crystal, though enriched by the appearance of a true rotator phase known only from longer alkane chains.Comment: 7 pages, 3 figure

Barriers to leisure participation for people with dementia and their carers: An exploratory analysis of carer and people with dementia's experiences.

Leisure has emerged as a prominent research theme within the growing body of knowledge on dementia, with a focus on physical activity. Yet participation in any form of leisure presupposes an ability to freely choose to partake in activities and to negotiate one's way around key barriers. In the case of dementia, the ability to undertake leisure activities is subject to a greater range of barriers, structured in a hierarchical manner that contributes to social exclusion if not addressed. This study based on focus groups with people with dementia and their family members conducted in Dorset, UK illustrates a range of barriers to leisure participation. How to create or maintain leisure opportunities for those living with dementia where households affected by dementia do not adopt avoidance behaviour, compounding a sense of isolation and exclusion is a challenge. Leisure can be an important strategy framed as a form of resistance to the social disabilities experienced by those living with dementia and it is potentially isolating impact

A new microporous zeolitic silicoborate (ITQ-52) with interconnected small and medium pores

A new zeolite (named as ITQ-52) having large cavities and small and medium channels has been synthesized. This was achieved by using a new family of amino-phosphonium cations as organic structure directing agents (OSDA). These cations contain P−C and P−N bonds, and therefore they lie between previously reported P-containing OSDA, such as tetraalkylphosphonium and phosphazenes. In this study, it has been found that 1,4- butanediylbis[tris(dimethylamino)]phosphonium dication is a very efficient OSDA for crystallization of several zeolites, and in some particular conditions, the new zeolite ITQ-52 was synthesized as a pure phase. The structure of ITQ-52 has been solved using high-resolution synchrotron X-ray powder diffraction data of the calcined solid. This new zeolite crystallizes in the space group I2/m, with cell parameters a = 17.511 Å, b = 17.907 Å, c = 12.367 Å, and β = 90.22°. The topology of ITQ-52 can be described as a replication of a composite building unit with ring notation [435461] that gives rise to the formation of an interconnected 8R and 10R channel system.We thank financial support by the Spanish Government (MAT2012-38567-C02-01, MAT2012-38567-C02-02, Consolider Ingenio 2010-Multicat CSD-2009-00050 and Severo Ochoa SEV-2012-0267). R.S. acknowledges to UPV for a FPI predoctoral fellowship. Authors thank ALBA Light Source for beam allocation at beamline MSPD. We thank G. Sastre and J. A. Vidal for computational calculations and MAS NMR experiments, respectively.Simancas Coloma, R.; Jorda Moret, JL.; Rey Garcia, F.; Corma Canós, A.; Cantin Sanz, A.; Peral, I.; Popescu, C. (2014). A new microporous zeolitic silicoborate (ITQ-52) with interconnected small and medium pores. Journal of the American Chemical Society. 136(9):3342-3345. doi:10.1021/ja411915cS33423345136