Lightweight nanoporous metal hydroxide-rich zeotypes

Abstract

nanoporous materials have important industrial applications as molecular sieves, catalysts and in gas separation and storage. They are normally produced as moderately dense silicates (sio 2 ) and aluminosilicates making their specific capacities for the uptake and storage of gases, such as hydrogen, relatively low. Here we report the synthesis and characterization of lightweight, nanoporous structures formed from the metal hydroxide Be(oH) 2 in combination with relatively low levels of framework phosphate or arsenate. Three new zeotype structures are described, constructed mainly of Be(oH) 4 tetrahedra bridged through hydroxide into threemembered rings; these units link together to produce several previously unknown zeotype cage types and some of the most structurally complex, nanoporous materials ever discovered. These materials have very low densities between 1.12 and 1.37 g cm − 3 and theoretical porosities of 63-68% of their total volume thereby yielding very high total specific pore volumes of up to 0.60 cm 3 g − 1 .

Driving the Crystallization of Zeolites

“…In these materials, Be or Zn belong to a 3MR and a high degree of order in the distribution of Si and Be or Zn over the available tetrahedral sites was observed ,,,,. 3MR have been found in materials with similar or more exotic compositions: in natural berillosilicates roggianite (‐RON), and nabesite (NAB), synthetic berillosilicate OBS‐2 (OBW), natural berillophosphate weinebenite (WEI), natural zincosilicate gaultite (isomorphous to VPI‐7, VSV), the synthetic beriloarsenate BOZ, and oxonitridophosphate‐2 (NPT) . And at least one lithium silicate with a true 4,2‐3D zeolitic nature and containing 3MR, RUB‐23, was also synthesized …”

Immune Modulation by Human Secreted RNases at the Extracellular Space

“…Therefore, extracellular RNases are key players that ensure tissue health and body homeostasis. Indeed, we find examples of genetic deficiencies in extracellular RNases that lead to immune-related diseases, such as amyotrophic lateral sclerosis (ALS), associated with human RNase5 mutations ( 21 , 22 ) and cystic leukoencephalopathy, a neuronal disorder associated with RNaseT2 deficiency ( 23 , 24 ). Potential RNA-targeted therapeutic applications for secretory RNases were envisaged as far back as two decades ago ( 25 – 27 ).…”

New compounds and structures in the solid state

“…The synthesis and characterisation of nanoporous structures formed mainly from Be(OH) 2 has been reported. 25 These materials contain Be(OH) 4 tetrahedra bridged through hydroxide ions into three-membered rings but also contain low levels of framework phosphate or arsenate groups. The three membered rings link together to produce several previously unknown zeotype cage types.…”