A new polymeric adsorbent material based on polyethylene (PE) was prepared by photografting of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) as a positively chargeable monomer to a PE film. The effects of the experimental parameters, such as the pH value, temperature, and grafted amount on adsorption of chromium(VI) (Cr(VI)) ions were investigated for the DMAEMA‐grafted PE (PE‐g‐PDAMEMA) films. The maximum adsorption capacity was obtained at the initial pH value of 3.0 for a PE‐g‐PDMAEMA film with 1.8 mmol/g and the maximum adsorption capacity obtained was higher than or compatible to those of many of the other polymeric adsorbents prepared for Cr(VI) ions. The adsorption kinetics obeyed the mechanism of the pseudo‐second order kinetic model and adsorption of Cr(VI) ions on PE‐g‐PDMAEMA films was well expressed by the Langmuir isotherm model. A high Langmuir adsorption constant suggests that the adsorption of Cr(VI) ions occurs between protonated dimethylamino groups and HCrO4− ions mainly through the electrostatic interaction. Cr(VI) ions adsorbed were successfully desorbed from a PE‐g‐PDMAEMA film in solutions of NaCl, NH4Cl, NH4Cl containing NaOH, and NaOH and a PE‐g‐PDMAEMA film was regenerated and repeatedly used for adsorption of Cr(VI) ions without appreciable loss in the adsorption capacity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43360.
Background No studies have examined distribution, retention and use of maternal and child health (MCH) home-based records (HBRs) in the poorest women in low income countries. Our primary objective was to compare distribution of the new Afghanistan MCH HBR (the MCH handbook) to the poorest women (quintiles 1–2) with the least poor women (quintiles 3–5). Secondary objectives were to assess distribution, retention and use of the handbook across wealth, education, age and parity strata. Methods This was a population based cross sectional study set in Kama and Mirbachakot districts of Afghanistan from August 2017 to April 2018. Women were eligible to be part of the study if they had a child born in the last 6 months. Multivariable logistic regression models were constructed to adjust for clustering by district and potential confounders decided a priori (maternal education, maternal age, parity, age of child, sex of child) and to calculate adjusted odds ratios (aOR), 95% confidence intervals (95% CI) and corresponding p values. Principal components analysis was used to create the wealth quintiles using standard methods. Wealth categories were ‘poorest’ (quintiles 1,2) and ‘least poor’ (quintiles 3,4,5). Results 1728/1943 (88.5%) mothers received a handbook. The poorest women (633, 88.8%) had similar odds of receiving a handbook compared to the least poor (990, 91.7%) (aOR 1.26, 95%CI [0.91–1.77], p value 0.165). Education status (aOR 1.03, 95%CI [0.63–1.68], p value 0.903) and age (aOR 1.39, 95%CI [0.68–2.84], p value 0.369) had little effect. Multiparous women (1371, 91.5%) had a higher odds than primiparous women (252, 85.7%) (aOR 1.83, 95%CI [1.16–2.87], p value 0.009). Use of the handbook by health providers and mothers was similar across quintiles. Ten (0.5%) women reported that they received a book but then lost it. Conclusions We were able to achieve almost universal coverage of our new MCH HBR in our study area in Afghanistan. The handbook will be scaled up over the next three years across all of Afghanistan and will include close monitoring and assessment of coverage and use by all families. Electronic supplementary material The online version of this article (10.1186/s12889-019-7076-7) contains supplementary material, which is available to authorized users.
Polyethylene (PE) plates grafted with a neutral monomer, 2-hydroxyethyl methacrylate (HEMA), and a cationic monomer, 2-(dimethylamino)ethyl methacrylate (DMAEMA), (PE-g-PHEMA)-g-PDMAEMA plates were prepared by the two-step photografting. The Cr(VI) ion adsorption behavior of the (PE-g-PHEMA)-g-PDMAEMA plates was investigated as a function of the amounts of grafted HEMA, amount of grafted DMAEMA, initial pH value, and temperature. The adsorption capacity of the DMAEMA-grafted PE (PE-g-PDMAEMA) and (PE-g-PHEMA)-g-PDMAEMA plates had the maximum value at the initial pH value of 3.0, independent of the temperature. The adsorption capacity of (PE-g-PHEMA)-g-PDMAEMA plates increased with the amount of grafted HEMA (G) in the first-step grafting. The increase in the water absorptivity of the grafted layers and thereby the increase in the degree of protonation of dimethylamino groups on grafted PDMAEMA chains were found to lead to the increase in the adsorption capacity. This adsorption capacity was higher than or comparable to those of other polymeric adsorbents for Cr(VI) ions. The Cr(VI) ion adsorption behavior on both PE-g-DMAEMA and (PE-g-PHEMA)-g-PDMAEMA plates obeyed the mechanism of the pseudo-second-order kinetic model and was well expressed by Langmuir isotherm. The high values of the Langmuir constant suggest that the adsorption of Cr(VI) ions occurs through an electrostatic interaction between protonated dimethylamino groups on grafted PDMAEMA chains and [Formula: see text]ions. Cr(VI) ions were successfully desorbed from PE-g-PDMAEMA and (PE-g-PHEMA)-g-PDMAEMA plates in eluents such as NaCl, NaCl containing NaOH, NHCl, NHCl containing NaOH, and NaOH.
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