Column extraction and separation of some metal ions by diethylenetriamine polysiloxane immobilized ligand system

An extraction chromatographic solid porous polysiloxane functionalized by chelating diethylenetriamine ligand of the general formula P-(CH2)3-NH(CH2)2NH(CH2)2NH2, (Where P represents [Si-O]n siloxane network) has been evaluated for the separation of Co(II), Ni(II) and Cu(II) from aqueous solutions. The chromatographic parameters of the separation method have been optimized. The ligand system retained Co(II), Cu(II) and Zn(II) effectively when used as a metal ion extractant by controlling the pH value. The ligand system also shows a good separation of a mixture of metal ions Co(II), Ni(II) and Cu(II) when used as chromatographic stationary phase. The optimum separation pH values were 4.5, 4 for Co(II) and Ni(II) respectively, while a solution of 0.1 M HNO3 was used to elute Cu(II). Metal ions were also preconcentrated at pH 5.5. The chemisorbed metal ions were regenerated from the solid extractant using 0.5 M HCl

Preparation of Immobilized-Polysiloxane Salicylaldehyde Propylimine and Its Application

A porous solid polysiloxane ligand system of the general formula P-(CH2) 3-C7H6NO,(where P represents [Si-O] n siloxane network) has been prepared by modification of the immobilized 3-aminopropylpolysiloxane, P-(CH2) 3NH2 with an exsess of salicylaldehyde. The new modified polysiloxane system exhibits good potential for uptake of Co 2+ and Cu 2+ metal ions. This ligand system gives more stable complexes with the divalent metal ions than its parent 3-aminopropylpolysiloxane precursor. Characterization was achieved using elemental analysis and FTIR spectroscopy

Synthesis and Applications of a New Polysiloxane-Immobilized Macrocyclic Ligand System

Insoluble porous solid, macrocyclic 22-membered ring, 1-oxa-6,9,12,15,18-pentaaza-2,22-disilacyclododocosane polysiloxane ligand system has been prepared by the reaction of a macro-silane agent with tetraethylorthosilicate. The macro-silane agent was prepared by the reaction of imino-bis(N-2-aminoethylacetamide) ligand with 3-iodopropyltrimethoxysilane in 1:3 molar ratio. The new prepared polysiloxane system exhibits variable potentials for the extraction of metal ions (Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, and Pb2+) from aqueous solutions. The ligand system shows high capacity to extract silver, lead, and mercury. Chemisorption of the metal ions by the ligand system at the optimum conditions was found in the order Ag + > Pb2+ > Hg2+ > Cu2+ > Ni2+ > Fe3+ > Co2+ > Cd2+ > Zn2+

Uptake of divalent metal ions (Cu2+, Zn2+, and Cd2+) by polysiloxane immobilized diamine ligand system

Porous solid siloxane polymers carrying diamine functional group of formula P–(CH2)3NH–CH2CH2NH2 (where P–represents a silica-like siloxane framework) have been prepared by replacement of the iodine in iodopolysiloxane with ethylenediamine. The iodofunctionalized polysiloxane was prepared by polycondensation of Si(OEt)4 and (MeO)3Si(CH2)I. The polysiloxane diamine ligand system exhibits high potential for preconcentration of divalent metal ions (Cu2+, Zn2+, and Cd2+). The tendency to chemisorb these divalent metal ions by the diamine ligand system at the optimum conditions was found in the order: Cu2+ > Zn2+ > Cd2+. Diamine ligand system suffers from leaching of ligand containing groups upon treatment with acidic solutions

High prevalence of primary bile acid diarrhoea in patients with functional diarrhoea and irritable bowel syndrome-diarrhoea, based on Rome III and Rome IV criteria

Background A high prevalence of primary bile acid diarrhoea (BAD) has been reported for Rome III defined irritable bowel syndrome (IBS)-diarrhoea and functional diarrhoea. We determined whether this still applies under the contemporaneous Rome IV criteria, given that the latter characterises IBS-diarrhoea as having more frequent abdominal pain compared with previous iterations, whilst no longer recognising abdominal discomfort. Methods Patients referred for a 75SeHCAT test completed a baseline questionnaire comprising, i) demographic data, ii) risk factors for BAD (inflammatory bowel disease, bowel resection, cholecystectomy, microscopic colitis, celiac disease, abdominal-pelvic radiotherapy), iii) the Rome III and IV bowel disorder questionnaire, and iv) mood and somatisation scores. A diagnosis of BAD constituted a 75SeHCAT of ≤15%, with moderate to severe disease being defined as ≤10% and ≤5%, respectively. Findings Of 300 patients with complete dataset, 184 had no risk factors for BAD and fulfilled criteria for either IBS-diarrhoea or functional diarrhoea. The prevalence of primary BAD was 38% (n = 70/184), with almost half having moderate (n = 16) to severe (n = 17) disease. Using the Rome III criteria, the prevalence of primary BAD was 36% in IBS-diarrhoea (n = 63/173) and 64% (n = 7/11) in functional diarrhoea; p = 0.11. Using the Rome IV criteria, the prevalence of primary BAD was 38% (n = 53/139) in IBS-diarrhoea and 38% (n = 17/45) in functional diarrhoea; p = 0.97. Patients with primary BAD experienced more frequent loose stools (p = 0.01) and had a higher body mass index (p<0.0001) compared to those without BAD, but otherwise no significant differences were seen in age, gender, mood, somatisation, or abdominal pain. The presence of primary BAD in patients classified as overweight or obese was approximately 40% and 60%, respectively. Interpretation Over a third of patients with Rome IV IBS-diarrhoea or functional diarrhoea have primary BAD, similar to Rome III. We therefore recommend that, in secondary care settings, generic testing for primary BAD should be considered in patients presenting with chronic diarrhoea of presumed functional origin regardless of concomitant abdominal pain. Centres that lack tests for primary BAD, and who empirically treat instead, may consider targeting patients who are overweight or obese

The Impact of Building Information Modelling (BIM) Strategies in Energy Sustainability Elements to Sustainable Campus Using PLS-SEM Approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicate that the management and technical aspects of Energy Sustainability Elements (ESE) have a significant impact on sustainable campus with path coefficients of 2.447 and 5.032, respectively. The findings have revealed that hypothesis 1 and hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modelling (BIM) strategies in the context of energy efficiency

The Impact of Building Information Modelling (BIM) Strategies in Energy Sustainability Elements to Sustainable Campus Using PLS-SEM Approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicate that the management and technical aspects of Energy Sustainability Elements (ESE) have a significant impact on sustainable campus with path coefficients of 2.447 and 5.032, respectively. The findings have revealed that hypothesis 1 and hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modelling (BIM) strategies in the context of energy efficiency

PREPARATION OF IMMOBILIZED-POLYSILOXANE IMINO(2-AMINOETHYLACETAMIDE) AND ITS APPLICATION

porous solid polysiloxane ligand system of the general formula P-(CH2)3-NH-CH2COONHCH2CH2NH2, (where P represents [Si-O]n siloxane network) has been prepared by modification of the immobilized 3- aminopropylpolysiloxane, P-(CH2)3NH2, with ethyl chloroacetate followed by ethylenediamine. The new modified polysiloxane system exhibits good potential for uptake of metal ions (Co2+, Cu2+, Zn2+ and Pb2+). This ligand system gives more stable complexes with metal ions than its parent 3- aminopropylpolysiloxane precursor. Thermogravimetric analyses of this ligand system and its copper complex show high stability at relatively high temperature

Synthesis and structural characterization of a new macrocyclic polysiloxane-immobilized ligand system

A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula P–(CH2)3–C11H22O2N5 (where P represents [Si–O] n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+)

The impact of Building Information Modelling (BIM) strategies in energy sustainability elements to sustainable campus using PLS-SEM approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicates that the management and technical aspects of Energy Sustainability Elements (ESE) significantly impact sustainable campus with path coefficients of 2.447 and 5.032, respectively. Furthermore, the findings have revealed that Hypothesis 1 and Hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modeling (BIM) strategies in the context of energy efficiency