The sorption capacity of graphene oxide (GO) toward different metal cations has been the subject of several recent studies. However, the reported quantitative data are controversial, and the mechanism of chemical bonding between GO and metal cations is poorly understood. Clarifying these questions can eventually help to reveal the fine chemical structure of GO that remains ambiguous. In this work, we study the binding of Gd and Mn by GO in the presence of several competing metal cations by the H NMR relaxation method. As a general trend, the efficiency of the metal cations to bind to GO increases with ionic charge, and depends on their ability to form coordinate-covalent bonds with GO oxygen groups. The efficiency of the competing metal cations to "replace" Gd and Mn increases in the order Na < Cs < Ca < Sr < Ga < Lu. GO contains two different types of binding sites, bonding to which results in either high or low NMR relaxivity of the resulting Gd-GO and Mn-GO solutions. Gd and Mn, being replaced from the high-relaxivity sites by the large excess of competing cations, are not released into the bulk solution, but only migrate to the low-relaxivity sites, remaining covalently bonded to GO. The absolute majority of the existing carboxyl groups in GO are located at tiny few-carbon-atom-vacancy defects on the major planes. The density of these vacancy defects is estimated as one per every 200 carbon atoms.
Interpersonal mindfulness is a construct that significantly contributes to social interaction. To date, no validated measure assessing interpersonal mindfulness has been developed in Iran. Therefore, the aim of this study was to translate and validate the Interpersonal Mindfulness Scale (IMS) among Iranian undergraduate students. Participants in the study (370 undergraduate students; 220 females) from the Azad University completed the translated IMS, the Five Facet Mindfulness Questionnaire, and the Inventory of Interpersonal Problems Scale. The translated measure demonstrated acceptable face validity. All items had acceptable content validity and were deemed essential to the scale. The results of a Confirmatory Factor Analysis (CFA) confirmed a scale with four subscales (presence, awareness of self and others, non-judgmental acceptance, and non-reactivity), with acceptable internal consistency. The findings support the psychometric properties of the Persian translated Interpersonal Mindfulness Scale, which could be used to measure interpersonal mindfulness among undergraduate students in Iran.
Поступила в редакцию 09.04.19 Бурилова Евгения Александровна, кандидат химических наук, старший преподаватель кафедры неорганической химии Казанский (Приволжский) федеральный университет ул. Кремлевская, д. 18, г. Казань,
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