Considering the importance of determining potential hazards and factors that can cause anunexpected fire and due to the important role of nanotechnology to achieve more effectiveproperties, this paper presents our experiments on preparing nanocomposites based onPoly(ethylene terephthalate)(PET) and montmorillonite (MMT) as organoclay via meltblending with different clay loadings to investigate their combustion behavior. The mainobjective of this work was employing cone calorimeter as a perfect device to investigate allcombustion parameters such as time to ignition (TTI), heat release rate (HRR), mass lossrate(MLR), CO and CO2 release and peak of heat release rate (pHRR). Thermogravimetricanalysis (TGA), Cone calorimeter, limiting oxygen index (LOI) were employed to measurethermal stability and flammability of nanocomposite samples. Morphology and rheology ofclay /PET nanocomposites also were investigated using X-ray diffraction (XRD) andTransmission electron microscopy (TEM).The relationship between decrease of intrinsicviscosity and thermal behavior of sample also was studied. Results indicate that clay networkwas formed in nanocomposites samples which strongly affected flammability of burningsamples and resulted more residue during combustion which leads to decrease in dripping ofPET during melting. تفاصيل المقالة

The main objective of present work was improvement in flame retardancy (FR) of polyester fabric using modified clay as green flame retardant. Achieving mentioned purpose, first polyester fabric was alkaline treated then nanoclay was modified with chitosan to form organo-clay and used as FR finish to coat samples. The water absorption and bending resistance of pristine polyester, alkaline and modified clay-treated polyester were also measured to investigate physical properties of samples. Modified clay and surface treated polyester fabrics were characterized using X-ray diffraction (XRD), Fourier Transform Infrared spectrometer (FTIR/ATR) and scanning electron microscopy (SEM). It was concluded that chitosan- modified clay treatment has improving effect on flame retardancy of polyester samples through increase in limiting oxygen index (LOI), char yield and decrease in melt dripping while burning.Key Words: chitosan, nanoclay, polyester, alkaline treatment, Flame retardancy تفاصيل المقالة

Electro spraying is similar to electro spinning but when the viscosity of polymeric solution is not high enough to form nanofibers, electro spraying can be used to make nanoparticles .In this study Chitosan / gum tragacanth blend nanoparticles were produced using electro - spinning / sparying device and the chitosan and gum tragacanth concretions on properties of resulting nanoparticles was investigated . The morphology of electro - sprayed chitosan / gum tragacanth blend were characterized using scanning electron microscope (SEM) . The results showed that electro spraying technique is capable of forming gum tragacanth - chitosan blend nanoparticles with an average size of 200 to 300 nm . The miscibility of blend was determined using Fourier transform infrared spectrometer (FTIR) . Antibacterial property of samples was also investigated. Wettability results of gum tragacanth - chitosan nanoparticles ( Contact - angle measurements ) indicate hydrophilic property of nanoparticles which is needed for biocompatible applications.` تفاصيل المقالة

در این مطالعه، جذب موثر و سریع یون های مس بر نانوالیاف نقره/پلی آمید 6 (Ag/PA 6) از محلول آبی بررسی شد. سنتز سبز نانوذره های نقره با عصاره برگ گیاه نعنا دشتی انجام و نانوالیاف نقره/پلی آمید 6 با نانوذره های سنتزشده، تهیه شدند. نانوذره های نقره سنتزشده با میکروسکوپ الکترونی روبشی (SEM)، طیف‌سنجی فروسرخ تبدیل فوریه (FTIR) و پراش پرتو ایکس (XRD) شناسایی شدند. همچنین، ریخت شناسی نانوالیاف پلی آمید 6 و نانوالیاف نقره/پلی آمید 6 با میکروسکوپ الکترونی روبشی انجام شد. برای بهینه سازی عامل های تجربی از روش تک عاملی در یک زمان استفاده شد. بیشینه درصد حذف درpH برابر 5، زمان تماس 75 دقیقه، مقدار جاذب 2 گرم و غلظت اولیه 20 میلی گرم بر لیتر به دست آمد. بررسی مدل های هم دما نشان داد که هم دما لانگمویر با مقدار ضریب تعیین (R2) برابر با 0/9976، بهترین مدل برازش برای توصیف فرایند جذب بود. بیشنه ظرفیت جذب (qmax) برابر 71/42 میلی گرم بر گرم به دست آمد. افزون براین، مدل سینتیک شبه مرتبه دوم برای حذف یون های مس برازش بهتری را نشان داد (R2 برابر باR2 0/9994). نتیجه ها نشان دادند که Ag/PA 6 می تواند به عنوان یک جاذب ساده، کارآمد و سازگار با محیط زیست برای حذف آلاینده هایی مانند فلزهای سنگین از محیط های آبی استفاده شود. تفاصيل المقالة