Muna Bufaroosha

Bio: Muna Bufaroosha is an academic researcher from United Arab Emirates University. The author has contributed to research in topics: Materials science & Vinyl chloride. The author has an hindex of 5, co-authored 29 publications receiving 92 citations. Previous affiliations of Muna Bufaroosha include Thi Qar University.

The Effect of UV Aging on the Structure of PVC in the Presence of Organotin(IV) Compounds

Abstract: New photostabilizers of poly(vinyl chloride) (PVC) were synthesized and investigated the photostabilizing efficiency of the polymer films by ultraviolet (UV) experiment. The rate of photodecomposition constant have been calculated for PVC films as a method for evaluating the efficiency of the organotin(IV) complexes that used as a photostabilizers after 300 hour of irradiation. The results have showed that the additives had reduced the rate of photodecomposition constant of PVC films significantly with comparison to PVC (blank). The (kd) value for PVC films was the highest in the absence of any additives, and the lowest value in the presence of triphenyltin (IV) complex.

Synthesis of Carvedilol-Organotin Complexes and Their Effects on Reducing Photodegradation of Poly(Vinyl Chloride).

Abstract: Poly(vinyl chloride) (PVC) undergoes photodegradation induced by ultraviolet (UV) irradiation; therefore, for outdoor applications, its photostability should be enhanced through the use of additives. Several carvedilol tin complexes were synthesized, characterized and mixed with PVC to produce thin films. These films were irradiated at 25 °C with a UV light (λ = 313 nm) for up to 300 h. The reduction in weight and changes in chemical structure and surface morphology of the PVC films were monitored. The films containing synthesized complexes showed less undesirable changes than the pure PVC film. Organotin with a high content of aromatics was particularly efficient in inhibiting photodegradation of PVC. The carvedilol tin complexes both absorbed UV light and scavenged radicals, hydrochloride, and peroxides and, therefore, photostabilized PVC.

A Process for the Synthesis and Use of Highly Aromatic Organosilanes as Additives for Poly(Vinyl Chloride) Films

Abstract: Three organosilanes were synthesized in good yields from the condensation of 4,4′,4″-((phenylsilanetriyl)tris(oxy))tribenzaldehyde and 4-substituted anilines under acidic conditions. The structure of the organosilanes was confirmed using a variety of techniques. Organosilanes were mixed with poly(vinyl chloride) (PVC) and homogenous films were produced. The effect of long-term irradiation on the films containing organosilanes was tested using various methods. Monitoring the infrared spectra of PVC films before, during and after irradiation processes showed the formation of side products comprising polyene, carbonyl and hydroxyl groups. The intensities of absorption bands due to these functional groups were much lower in the presence of organosilanes as compared to the blank film. Also, the decrease in the weight and molecular weight of PVC films after irradiation was lower in the presence of organosilanes. Additionally, there was a minimal surface change of irradiated PVC in the presence of organosilanes. Clearly, organosilanes act as inhibitors, particularly the one containing the hydroxyl group, for the photodegradation of PVC. Different mechanisms were proposed to speculate the role played by organosilanes in stabilizing PVC against long-term ultraviolet light exposure.

Amino-Functionalized Luminescent Metal-Organic Framework Test Paper for Rapid and Selective Sensing of SO2 Gas and Its Derivatives by Luminescence Turn-On Effect.

Abstract: Rapid and selective sensing of sulfur dioxide (SO2) gas has attracted more and more attention because SO2 not only causes environmental pollution but also severely affects the health of human beings. Here we report an amino-functionalized luminescent metal-organic framework (MOF) material (i.e., MOF-5-NH2) and further investigate its sensing property for SO2 gas and its derivatives as a luminescent probe. The results indicate that the MOF-5-NH2 probe can selectively and sensitively sense SO2 derivatives (i.e., SO32-) in real time by a luminescence turn-on effect with a lower detection limit of 0.168 ppm and a response time of less than 15 s. Importantly, the luminescence turn-on phenomenon can be observed by the naked eye. We also assembled MOF-5-NH2 into a test paper to achieve the aim of portable detection, and the lower-limit concentration of the test paper for sensing SO2 in real time was found to be about 0.05 ppm. Moreover, MOF-5-NH2 also shows good anti-interference ability, strong luminescence stability, and reusability, which means that this material is an excellent sensing candidate. The amino functionalization may also provide a modification strategy to design luminescent sensors for other atmospheric pollutants.

Applications of Cucurbiturils in Medicinal Chemistry and Chemical Biology.

Abstract: The supramolecular chemistry of cucurbit[n]urils (CBn) has been rapidly developing to encompass diverse medicinal applications, including drug formulation and delivery, controlled drug release, and sensing for bioanalytical purposes. This is made possible by their unique recognition properties and very low cytotoxicity. In this review, we summarize the host-guest complexation of biologically important molecules with CBn, and highlight their implementation in medicinal chemistry and chemical biology.

Cucurbit[7]uril: an emerging candidate for pharmaceutical excipients

Abstract: Cucurbit[7]uril (CB[7]), belonging to the cucurbit[n]uril family (CB[n], n = 5-8, 10, or 13-15), may form host-guest complexes with a variety of small molecules of biomedical interest. The physical and chemical properties of the complexed drugs are often improved as a result of this complexation, suggesting the potential application of CB[7] as a pharmaceutical excipient. This review has summarized the most recent research progress reported between 2011 and early 2017 regarding the biocompatibility of CB[7] and the influence of CB[7] on the stability, solubility, biouptake, and biological activities (including therapeutic efficacies and toxicities) of guest drug molecules. Through this systemic summary and analysis, we intend to stimulate further research efforts in this area and promote the use of CB[7] as an emerging pharmaceutical excipient to improve various properties of drug molecules (or active pharmaceutical ingredients).

Supramolecularly assisted modulations in chromophoric properties and their possible applications: an overview

Abstract: In this article our aim is to review the supramolecularly assisted modulations in the properties of the organic chromophoric dyes, on their interactions with the macrocyclic host molecules, focusing on the possible uses of such modulated dye properties in different applications. We restrict ourselves on the modulations of two important properties of the chromophoric dyes, namely the fluorescence characteristics and the prototropic behavior, the properties that usually undergo large changes through host–guest inclusion complex formation of the dyes with the macrocyclic host molecules and show great prospects for their applications in diverse areas like sensors, catalysis, functional materials, electronic devices, pharmaceuticals, drug formulations, drug delivery, nanomedicines, and many others. To restrain the length of the article, our discussion has also been restricted to only two types of macrocyclic molecules, namely cyclodextrin (CD) and cucurbit[n]uril (CBn) hosts, that are realized to be most promising cavitand molecules with regard to their influence in modulating the dye properties leading to their applications in the aforementioned areas. We have considered suitable examples from the dye–CD and dye–CBn systems as reported in the literature by different research groups including ours to substantiate the discussions on different aspects of the macrocyclic hosts and those on the modulations of the fluorescence and acid–base properties of the organic chromophoric dyes, bringing out their possible applications in different areas, as have been the main objectives of the present review. We strongly feel that this review article will showcase the titled theme, i.e. the supramolecularly assisted modulations in the properties of the chromophoric dyes, which can lead to different useful applications of the supramolecular host–guest systems, highlighting the immense prospects of such studies to explore the versatility of the supramolecular host–guest assemblies for their applications for the benefit of the mankind.