خالدة حسين حبيب الميالي

Hybrid nanomaterials attract significant interest from scientists and industry due to their diverse bio-physical properties and their potential for dual applications. New nanocomposites were fabricated by loading polyethyleneimine (PEI) into a hydroxypropyl methyl cellulose (HPMC)- blended polymer. These blended polymers were reinforced with graphene oxide (GO) functionalized with MXene (Ti3C2) nanosheets to obtain (HPMC-PEI/GO@Ti3C) nanocomposites. The developed acoustic-mixing-ultrasonic-casting procedure was applied to improve nanomaterial dispersion in the matrix. Fourier transform infrared spectroscopy showed strong bonding and interfacial interaction between the nanomaterials and the polymers. The main polymer structure does not change upon loading nanomaterials, as demonstrated by the X-ray diffraction spectrum. Optical microscopy and field emission scanning electron microscopy revealed fine homogeneity of the polymer matrix and excellent dispersion of nanosheets in the nanocomposites. Optical absorbance increased from 3.45 to 3.98 at 200 nm wavelength, whereas the energy gap significantly decreased from 5.1 eV to 2.4 eV and from 5.4 eV to 3 eV for allowed and forbidden transitions, respectively. Interestingly, functional GO@MXene showed notable improvements in the inhibition zone, up to 21 mm for Streptococcus mutans and 14.5 mm for Acinetobacter baumannii, which is the first time this has been reported against these materials. Whereas the loading of nanomaterials in the polymer matrix presented an enhancement of up to 22 mm and 17 mm, respectively. Loading functional GO-MXene nanomaterials presented the best results compared to using GO to reinforce the blended polymers. New nanocomposites revealed promising applications in flexible optoelectronic and biological devices.

AZO/CuO/Si solar cells have been successfully fabricated by using simple and low-cost techniques. Hot water treatment method has been used to prepared p-type CuO nanostructures onto n- type Si substrate by immersing Cu films in hot DI water at 70 °C for 7hrs. Then, as grown CuO nanoleaf structures were coated with thin shell of AZO using high-pressure sputtering technique. Such prepared CuO nanoleaves structural quality have been investigated by employing XRD and analysis and SEM images. The optical properties have been studied by UV–vis -NIR spectrum. Also, electrical device performance with AZO/CuO/Si structure was investigated using I-V measurements. Results demonstrated that CuO nanoleaves exhibit a relatively broad absorption spectrum in the ultraviolet and visible regions. The obtained photocurrent density response value of the nanostructured p-CuO/ n-Si heterojunction with AZO shell was 10.3 ± 0.1 μA/cm2. Also, I-V measurements indicated that a rectifying Schottky junction is formed between p-type CuO NSs and the n-type Si substrate. This study suggests that the device based on an CuO/Si structure can potentially serve a wide range of simple and low-cost optical applications.

Numerical simulation of the light intensity distribution in the cadmium telluride (CdTe) films-based solar cell was carried out using a finite-difference time-domain (FDTD) solver. FDTD method was used to predict the optical properties of CdTe films having different thicknesses (100, 500, 1000, 3000, and 5000) nm on a glass substrate. The absorption, transmittance, and reflectance are detected over a wavelength range of 300–800 nm. The numerical results reveal that the optical absorption increased with increasing CdTe film thickness. FDTD simulation predicted that the CdTe active layer with a thickness of 3.0 µm has a higher absorption spectrum. However, increasing the CdTe thickness to 5 µm had no effect on the absorption. It is also observed that there is a decrease in optical band gap with increasing film thickness. This study could be useful for developing highly efficient and inexpensive CdTe-based thin film solar cells.

We have investigated the influence of film thickness on the optical properties of cadmium sulfide CdS thin film. The theoretical analysis is performed using the finite-difference time-domain (FDTD) method on the plane thin film structures. The FDTD approach is used to solve the Maxwell’s equations in three dimensions of CdS thin films on glass substrates with different thicknesses (100 nm- 500 nm) to analyze wave propagation within the thin film structure. Measurements of the absorption, transmittance, and reflectance were carried out over the wavelength range of 300– 800 nm. According to FDTD simulation results, the optical absorbance increased with increasing CdS film thickness,. A numerical calculation suggested that the CdS active layer with a thickness of 500 nm has a greater absorption spectrum. On the other hand, the further increase of CdS thickness showed no more effect on the absorptance, where their absorption spectra behave similarly to each other. This research can help to develop thin film-based optoelectronic devices that are both low-cost and highly effective.

Molecular weight (Mw) is an important feature that affects the physicochemical properties of polymers and their matrices. This study focused on the impact of increasing the Mw of polyethylene glycol (PEG) (4, 8 and 20 K) mixed with polyvinyl alcohol (PVA). Graphene oxide (GO) nanosheets were employed to reinforce the polymer matrix by aquatic mixing-sonication-casting to prepare the nanocomposites and investigate their optical properties. Fourier transform infrared spectroscopy revealed strong interfacial interactions among the components and successful fabrication of the nanocomposites. Optical microscopy and scanning electron microscopy confirmed the fine homogeneity of the polymers and the excellent dispersion of nanosheets in the matrix. The absorption peak was located in the ultraviolet region related to GO. PEG Mw and GO additive significantly improved optical properties such as absorbance, real and imaginary dielectrics and the absorption coefficient constant up to 75%, 40%, 120% and 77%, respectively. An enhancement in the optical properties was also observed after the energy gap values for allowed and forbidden transitions were improved up to 90% and 375%, respectively. These findings suggest the potential of these materials for several applications, such as in photovoltaic devices and heavy metal ion absorption for nuclear waste management.

Antibiotic resistance has been on the rise due to the overuse of antibiotics in the agricultural industry. This has led to an increase in foodborne illnesses and a need for alternative modes of action to help mitigate bacterial growth. This study broaches the potential applications of hot water-treated (HWT) aluminum foil for use in the food packaging industry. Through HWT, a layer of aluminum oxide nanostructures is formed on the surface of the foil, which conveys antibacterial properties. Here, we demonstrate the efficacy of HWT aluminum foil in preventing bacterial growth of Escherichia coli on red meat. Aluminum foil samples were treated in hot water at different temperatures including 75 °C, 85 °C, and 95 °C. It was found that HWT foils were 95–100% effective in preventing bacterial growth, while the efficacy of untreated foil was only ~ 30%. Enhanced efficacy of HWT samples is believed to be due to improved release of reactive oxygen species from high surface area aluminum oxide nanostructures and a physical rapturing mechanism associated with the penetration of nanostructures through the bacteria membrane. This research presents a nontoxic, cost-effective means of curbing foodborne illnesses caused by bacteria.

( دراسة خصائص و أداء المتراكبات النانوية ( مادة عضوية – أكاسيد المعادن)للتطبيقات الحديثة

هدفت الرسالة الى تحضير ودراسة تأثير التلبيد والاستبدال الجزئي على الخصائص الفيزيائية للمركب وتأثيره على الخصائص الفيزيائية من حيث طبيعة الاطوار المتكونة ونسب تركيزها ونوع التركيب ومن ثم تحديد افضل درجة حرارة تلبيد له.

يهدف هذا العمل الى دراسة تأثير تغير سمك كل من اغشية تيلوريد الكادميوم وكبريتيد الكادميوم على الخصائص البصرية التي تتمثل ب (الامتصاصية ,الانعكاسية ,النفاذية ) و تفسير سلوك الضوء فيها من خلال اجراء محاكاة نظرية باستخدام طريقة الفروقات المنتهية في المجال الزمني (FDTD ). ليتم بعد ذلك دراسة تأثير شكل سطح الخلية الشمسية على تحسين الخصائص البصرية من اجل الحصول على كفاءة عالية ومنخفضة التكلفة للأجهزة الكهروضوئية باستخدام طريقة الفروق المحدود في المجال الزمني ( FDTD ).

شاركنا في يوم الاثنين المصادف في 20/9/2021 في لجنة مناقشة رسالة ماجستير للطالبة نسرين رحيم والتي اقيمت في قسم الفيزياء , كلية التربية للعلوم الصرفة, جامعة بابل.

شاركنا وبحمد الله في يوم الاربعاء المصادف في 15/12/2021 في لجنة مناقشة اطروحة دكتوراه الطالب رسول محمد كريم بعنوان الخصائص الكمية لانابيب البروفين النانوية والتي اقيمت في قسم الفيزياء , كلية التربية للعلوم الصرفة, جامعة بابل.