Amorphous and ordered organosilicas functionalized with amine groups as sorbents of platinum (II) ions

Abstract

Two groups of amine-functionalized organosilicas have been synthesized: amorphous polysiloxane xerogels (APX) and ordered mesoporous organosilicas (OMO) by co-condensation of tetraethoxysilane and appropriate alkoxysilanes: aminopropyltriethoxysilane and N-[3-(trimethoxysilyl)propyl]ethylenediamine. The obtained materials were characterized by sorption measurements, X-ray diffractometry, elemental analysis, transmission electron microscopy, and scanning electron microscopy. The OMO samples have well developed porous structure-the values of specific surface area are in the range 740-840 m 2 / g. While the APX samples are less porous having the corresponding values in the range 280-520 m 2 /g. The sizes of the ordered mesopores of OMO are in the range 5.9-6.5 nm while for the APX they are 2.9-12.1 nm indicating structural differences between both groups of the samples. All samples were tested as the sorbents of Pt(II) ions. The influence of various parameters such as pH, contact time, equilibrium concentration on Pt(II) adsorption ability onto prepared adsorbents was studied in detail. Additionally, the effect of chloride concentration on Pt(II) adsorption was investigated. The values of static sorption capacities were in the range of 32-102 mg Pt(II)/ g and 20-139 mg Pt(II)/ g for OMO and APX series, respectively.

Tailoring Surface Chemistry of Sugar-Derived Ordered Mesoporous Carbons towards Efficient Removal of Diclofenac from Aquatic Environments

“…The images reveal a typical 'sausage-like' structure characteristic of OMC materials [10], i.e., micrometer-size bundles of aggregated rods. This morphology is also typical of SBA-15 template [32], which confirmed a good SBA-15 to CMK-3 replication process. The morphologies of the modified OMC materials resembled each other and also that of initial P-CMK material, which means that the morphological changes caused by modifications were negligible.…”

Influence of bridged monomer on porosity and sorption properties of mesoporous silicas functionalized with diethylenetriamine groups

“…Chemical functionalization is almost always applied to alter the final properties and bring templated mesoporous silica materials closer to a wide range of environmental remediation applications. Two different strategies are usually employed to provide the desired surface modification: co-condensation (Barczak et al 2013;Yokoi et al 2003;Zhang et al 2008) and post-synthesis grafting (Mureseanu et al 2008;Trindade et al 2012;Yokoi et al 2003). Both strategies lead to the materials differing in the reactivity, pore accessibility and distribution of functional moieties, both have also some disadvantages (Barczak 2018).…”

“…Many different pendant functional groups has been successfully attached by co-condensation and/or grafting including hydrocarbon groups (e.g., alkyl (Barczak et al 2009a;Li et al 2015), vinyl (Barczak et al 2009bWang et al 2004), phenyl (Barczak et al 2010b;Fan et al 2017;Huang et al 2013)) as well as the groups with complexing properties (amine (Barczak et al 2013;Chong and Zhao 2003;Dobrowolski et al 2013;Zhu et al 2012), thiol (Barczak et al 2016Crudden et al 2005;Liu et al 2000), pyridine (Barczak 2018), carboxyl (Han et al 2007;Shen et al 2008;Tsai et al 2016)). Co-condensation also allows for incorporation of bridged multi-silylated monomers resulting in the so-called periodic mesoporous organosilicas (Asefa et al 1999;Inagaki et al 2002;Mizoshita et al 2011;Yoshina-Ishii et al 1999).…”

“…To date amine-functionalized mesoporous materials have been widely tested for removal of heavy metal ions (Aguado et al 2009;Barczak et al 2013;Da'na 2017;McManamon et al 2012), phenols (Toufaily et al 2013), H 2 S (Jaiboon et al 2014), sequestration of carbon dioxide (Chang et al 2009;Gunathilake et al 2016) but their use for removal of hazardous pharmaceuticals from aqueous media is barely explored (Barczak et al 2018). Amine groups are usually incorporated by the use of aminopropyltriethoxysilane (APTES) or aminopropyltrimethoxysilane (APTMS) either by co-condensation or post-synthesis grafting.…”

Facile preparation of mesoporous silica/nano zero-valent iron composite for Pb(II) removal from aqueous solution

“…Silica-based inorganic-organic hybrid materials have been widely studied for removal of heavy metals [12][13][14]. Mesoporous silica materials modified with amino or thiol functional groups are promising adsorbents, which exhibit specific adsorption properties and larger adsorption capacity towards heavy metals [15,16]. However, it is necessary to use a large excess of organics during the synthesized process.…”