Synthesis and characterization of Poly HEMA-co-AAc /Diatomite hydrogel composites: Their application for heavy metal removal from the aqueous solution

P oly 2-hydroxyethyl methacrylate-co-acrylic acid /diatomite hydrogel composite DHC materials were synthesized using in situ free radical addition polymerization technique. The effects of particle size and amount of diatomite were investigated on swelling properties such as the swelling degree SD , equilibrium swelling degree ESD and water retention WR of DHC. The particle size and amount of diatomite were not affected clearly in the swelling properties. The synthesized DHC with the particle size of -45μm and the amount of 5 wt % of diatomite showed the highest swelling properties. The SD g/g , WR % and ESD % values of hydrogel were increased up to 29.2, 45.5 and 96.7 from 1.1, 41.3 and 89.3 by adding diatomite into the structure of hydrogel, respectively. The hydrogel and DHC were characterized using Fourier transform infrared spectrometer FTIR and an optical microscope. Also, their thermal behavior was analyzed by differential scanning calorimeter DSC . The FTIR spectrums showed that diatomite incorporated into the hydrogel matrix at the high amount of diatomite. The DSC results indicated that the glass transition temperature Tg and melting temperature Tm of hydrogel increased with the addition of 2 wt % diatomite. The adsorption studies were performed using the hydrogel composite including 5 wt % of diatomit

Nem ve sıcaklık algılama için iletken poli(o-toluidin)/kaolinit kompozitlerinin sentezi ve karakterizasyonu

İletken poli(o-toluidin)/kaolinit kompoziti, kaolinit varlığında yükseltgen olarak amonyum persülfat kullanılarak o-toluidinin kimyasal polimerizasyonu ile hazırlandı. Hazırlanan iletken kompozitin nem ve sıcaklık algılayıcısı olarak kullanımını araştırabilmek için kompozitin içerdiği iletken POT miktarı ve kompozitin iletkenlik değerlerine polimerizasyon koşullarından HCl, o-toluidin ve yükseltgen madde derişimlerinin etkisi incelendi. En yüksek poli(o-toluidin) miktarı (%29.4) ve iletkenliğe sahip (8.3×10-4 Scm-1) kompozitin 0.2 M amonyum persülfat, 0.4 M o-toluidin ve 1.0 M hidroklorik asit kullanılarak 20 °C sıcaklıkta ve 2 sa. sürdürülen polimerizasyon ile elde edildiği bulundu. Saf poli(o-toluidin) ve poli(o-toluidin)/kaolinit kompozitinin direnç değerleri 0-100 °C sıcaklık aralığında tekrar edilen ısıtma-soğutma işlemleri sırasında izlenerek sıcaklığa karşı duyarlılığı incelendi. Bağıl nem oranı %30-90 arasında değiştirilen ortamlarda saf poli(o-toluidin) ve kompozitin direnç değerleri ölçülerek nem sensör davranışı belirlendi. Hazırlanan kompozitin karakterizasyonu Fourier dönüşümlü kızılötesi spektroskopisi (FT-IR), X-Işınları kırınımı (XRD), termogravimetrik analiz (TGA) ve taramalı elektron mikroskobu (SEM) teknikleri ile yapıldı

Aloe vera-based antibacterial porous sponges for wound dressing applications

The antibacterial sponges with high macroporosity, high interconnectivity and high biocompatibility is a significant concern for wound healing applications. In this work, novel Aloe vera (AV) based sponges were developed via subsequent lyophilization with further chemical crosslinking throughout the double network sponges. Single network was composed of gelatin-sodium alginate (G-SA) while the double network using gelatin-sodium alginate- sodium hyaluronate (G-SA-HA) was produced with the addition of hyaluronic acid solution into the gelatin-sodium alginate matrix. Lastly, Aloe vera as the bioactive agent was fabricated throughout the gelatin-sodium alginate-sodium hyaluronate matrix. The AV-based sponges demonstrated large pores with high interconnectivity. The swelling degree of the AV-based sponges were higher than that of G-SA and G-SA-HA sponges. The release of AV from the sponges reached an equilibrium value after 24 h showing a more controlled release at pH 5.5 than at pH 7.4. AV-based sponges showed antibacterial activity against Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae and Bacillus cereus and displayed any cytotoxicity against Mesenchymal stem cells.Hitit University ; Hitit University Scientific and Tecnical Application and Research Cente

Dye removal by dead biomass of newly isolated <em>Pleurotus ostreatus</em> strain

290-301Dead biomass prepared from newly isolated Pleurotus ostreatus strain was tested for their efficiency in removal of indigo carmine. The effects of operational parameters such as contact time, initial dye concentration, amount of biomass, initial pH and agitation rate on removal were examined. The dye removal increased rapidly during the first 60 minutes (87%) and remained nearly constant between 60 - 120 minutes of adsorption (87 - 90%). The removal of dye by dead biomass of newly isolated P. ostreatus was clearly dependent on the initial dye concentration of the solution and dye removal was reduced from 83% to 53% as concentration was increased from 100 to 500 mg/L indigo carmine. Results were analyzed by the Langmiur, Freundlich, Dubinin-Redushkevich (D-R), Temkin, Frumkin, Harkins-Jura, Halsey, Henderson isotherm using linearised correlation coefficient. The kinetics of adsorption of IC have been discussed using six kinetic models, i.e., the pseudo first order model, the pseudo second order model, the Elovich equation, the intraparticle diffusion model, the Bangham equation, the modified Freundlich equation. In order to determine the best fit isotherm and kinetic models, three error analysis methods of residual mean square error (RMSE), chi-square (X2) statistic and the average percentage error (APE%) were used to evaluate the data

Synthesis of a novel fluorinated graphene oxide hybrid material based on poly(2,3,4,5,6-pentafluorostyrene) and its use as a filler for thermoplastic polyurethane film

In this study, graphene oxide (GO) was synthesized via modified Hummers method. The GO was grafted with poly(2,3,4,5,6-pentafluorostyrene) (PPFSGO) by surface initiated atom transfer radical polymerization (SIATRP). This material was used as a novel filler for thermoplastic polyurethane (TPU) to prepare composite films via solution casting method. FTIR, Raman and XRD spectroscopy analyses confirmed the formation of proposed hybrid structure. SEM analysis indicated that the GO layers of PPFSGO were exfoliated and decorated with weblike PPFS. Particularly, the contact angle measurements showed that the contact angle of TPU based composite films could be increased by 20% compared to bare TPU film with the incorporation of 10 wt% of PPFSGO while preserving thermal stability and electrically insulating properties. These results revealed that the herein proposed PPFSGO hybrid material is a promising candidate to adjust the wettability of TPU films without compatibility issues

Young children's sleep patterns and problems in paediatric primary healthcare settings: a multicentre cross-sectional study from a nationally representative sample

Studies describing paediatric sleep patterns are needed by taking culture into consideration. The aim of this study was to identify parent-reported sleep-wake patterns in young children and explore possible factors influencing sleep problems. The mothers of 2,434 young children enrolled from well-child outpatient clinics in Turkey completed an online survey including sociodemographic variables, Brief Infant Sleep Questionnaire, Edinburgh Postnatal Depression Scale and Generalised Anxiety Disorder scales. Overall, young children in Turkey go to bed late (10:00 p.m.), awaken twice per night for 30 min, and obtain 11.5 h of total sleep, showing no sex-specific differences. Distinct night-time sleep patterns emerged after 18 months of age. Importantly, although currently breastfed healthy children were 3.8-times less likely to sleep through the night, total sleep duration and exclusive breastfeeding duration were higher in children who were not sleeping through the night. Overall, bedsharing was identified in 11.5%, and only room sharing was reported in 52.9%. Parental perception of a child's sleep as problematic was 35.8%. Mothers with higher educational attainment were more likely to perceive their children's sleep as a problem. Maternal depressive and anxious symptoms and a history of excessive infant crying were the determinants predicting the likelihood of both parent-perceived sleep problems and poor sleepers. The present analysis of sleep structure in infancy and toddlerhood provides reference data for well-child visits. These findings highlight the importance of considering maternal anxiety, depression and behaviour management techniques to cope with fussy infants in addressing childhood behavioural sleep problems