Browsing by Author "Alsahli, Sultan"

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RECYCLABLE THERMOPLASTIC ELASTOMERS FROM DYNAMICALLY CROSSLINKED HAIRY NANOPARTICLES (HNPs)
(Clark Atlanta University, 2024-12) Alsahli, Sultan; Khan, Ishrat
Chain-end furan-functionalized hairy nanoparticles (HNPs) with robust polystyrene (PS) cores and flexible polydimethylsiloxane (PDMS) shells were successfully synthesized through a one-pot high vacuum anionic living polymerization process. The synthesis involved the preparation of the living core by copolymerizing styrene and divinylbenzene, followed by the addition of hexamethylcyclotrisiloxane (D3) as the second monomer to the living polystyrene core. The resulting living polymer was terminated with dimethylchlorosilane, yielding HNPs terminated with Si-H functional end groups (HNP-SiH). Furan-functionalized HNPs were then obtained by hydrosilylation of HNP-SiH with 2-vinylfuran to (HNP-F). In parallel, furan end-functionalized poly(dimethylsiloxane) and poly(styrene) were synthesized using anionic living polymerization. The successful synthesis of these structures was confirmed through 1H NMR and FT-IR spectra. Differential scanning calorimetry revealed two thermal transitions of HNP, indicating the presence of a poly(dimethylsiloxane) soft phase and a poly(styrene) hard phase, classifying the HNP as thermoplastic elastomers. A Diels−Alder chemistry approach was employed as a proof of principle for creating thermoreversible cross-linked networks in the polymer. Furan-functionalized HNP demonstrated the formation of thermoreversible elastomeric networks upon cross-linking with bismaleimide (BMI) via Diels−Alder coupling reactions. Kinetic studies of the forward Diels–Alder reaction between the functionalized polymer and BMI revealed a temperature-dependent increase in reaction rate constants, following second-order kinetics. The activation energy of the cross-linking reactions for furan functionalized HNP, PS, and PDMS with BMI were determined. The resulting retro-Diels−Alder cross-links in the polymer dissociated at elevated temperatures (around 140–154 °C), as confirmed by (DSC). Scanning electron microscopy (SEM) was used to study the morphological changes of furan-functionalized hairy nanoparticles, polystyrene, and PDMS at the un-crosslinked, crosslinked, and decrosslinked stages in reaction with bismaleimide. The analysis provided detailed insight into structure development in such types of materials at each cross-linking stage. The results suggest that furan functionalized HNPs are promising building blocks for preparing thermo-reversible elastomeric networks.
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THE UPTAKE OF METAL IONS BY NaOH-TREATED PHEME
(Clark Atlanta University, 2019-12) Alsahli, Sultan; Bu, Xiu R
This thesis work is aimed to modify 2-hydroxyethyl methacrylate (PHEMA) hydrogels and to improve its property. The approach includes the treatment of PHEMA with aqueous NaOH. The basic hydrolysis condition creates hydrogel with CO2H groups in addition to the original OCH2CH2OH groups. The presence of CO2 was identified by Fourier Transform-Infrared Spectroscopy (FT-IR). The swelling property was examined and it is found that the modified hydrogel not only uptakes metal ions, such as Cu(II) and Ni(II), but also retains them.
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Understanding the Factors Influencing the Acceptance and Adoption of Mobile Health Applications by Physicians during the COVID-19 Pandemic: The Case of Saudi Arabia
(University of Technology Sydney, 2025-01) Alsahli, Sultan; Lam, Mary; Hor, Su-yin; Rogers, Kris
Background: The rapid evolution of mobile health applications has become increasingly crucial in enhancing healthcare delivery, particularly during the COVID-19 pandemic. Despite the critical role of these technologies, acceptance and adoption rates among physicians in developing countries, especially Saudi Arabia, have remained relatively low. This highlights the need to explore the determinants of their acceptance and adoption. Aim: This thesis aimed to investigate the key factors influencing Saudi physicians’ intentions toward using mHealth applications during the COVID-19 pandemic. Methods: This mixed methods research was conducted in three phases, each addressing specific objective and research question. In phase 1, a systematic review was conducted to present all available evidence of mHealth acceptance and adoption from the perspectives of physicians. Phase 2 applied a quantitative design based on the Unified Theory of Acceptance and Use of Technology (UTAUT) model to investigate key factors influencing physicians’ behavioural intentions to adopt mHealth apps. Data were collected via an online survey and analysed using structural equation modeling. Phase 3 employed a qualitative design, exploring additional context-specific factors not accounted for by the UTAUT model through semi- structured interviews. The qualitative data were analysed using template analysis. Results: The systematic review identified technological, individual, and organizational factors affecting physicians’ acceptance of mHealth apps during the pandemic. The quantitative study found that performance expectancy, effort expectancy, social influence, and facilitating conditions significantly influenced physicians’ intention to use mHealth applications. Qualitative findings highlighted additional factors unique to the Saudi context, such as concerns about data privacy, patient engagement, compatibility with religious and cultural norms, and the impact of COVID-19 pandemic. These factors shaped physicians’ perceptions and adoption behaviours, emphasizing the need for tailored strategies to promote mHealth in Saudi Arabia. Conclusions: This thesis extends the UTAUT model by incorporating context-specific factors relevant to developing countries like Saudi Arabia during the COVID-19 pandemic. The findings emphasize the need for investments in infrastructure, targeted training programs, and policies that address both technological and cultural concerns. By fostering an environment that supports the integration of mHealth applications into routine practice, healthcare organizations can improve both healthcare delivery and patient outcomes during health crises and beyond. The study provides critical insights for policymakers and healthcare managers seeking to enhance the acceptance and use of mHealth technologies in similar global contexts. Future research should examine the perspectives of other healthcare workers and patients for a comprehensive understanding of mHealth adoption while also exploring its long-term impact on patient outcomes and healthcare professionals.
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