Wedyan Babatain  Min Sung Kim  Muhammad Mustafa Hussain 《Advanced functional materials》2024,34(31):2470170

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Emre Akın;Mustafa Çakır;İlyas Kartal; 《Polymer Engineering and Science》2024,64(8):3854-3868

In this study, it was aimed to improve the mechanical and thermal properties of epoxy materials based on diglycidyl ether of bisphenol-A-based. For this purpose, three different nanocomposite materials were prepared at various ratios including a fumed silica nanoparticle-reinforced epoxy nanocomposite (FSN), an epoxy/silane-terminated urethane (STU) hybrid interpenetrating polymer network (IPN) nanocomposite (SHIN), and a fumed silica-reinforced epoxy/STU hybrid IPN nanocomposite (FSHIN). While synthesizing SHIN, 3-isocyanato propyl trimethoxy silane (ICPTMS) and poly (hexamethylene carbonate) diol were used. The synthesized STU polymer chains were crosslinked by reacting them with TEOS via the sol–gel process. Therefore, hybrid networks were obtained. Moreover, fumed silica nanoparticles were incorporated into the hybrid networks via the sol–gel process for FSHINs. The three different nanocomposite materials exhibited much more improved properties than the neat epoxy. The most prominent nanocomposite was FSHIN. In comparison with the neat epoxy, Young's modulus, ultimate tensile strength, and Izod impact resistance values increased at ratios of 53%, 50%, and 223%, respectively. Glass transition temperature values and char yield values increased substantially in all nanocomposites. However, thermal decomposition temperatures increased only for FSNs. Moreover, these values for FSHINs that were very close to those of the neat epoxy were considerably higher than those of SHINs.  相似文献   

    

Eoin G. McAleer  Mustafa K. Alazzawi  Chawon Hwang  Jacob M. LaManna  David L. Jacobson  Boris Khaykovich  Richard A. Haber  E. Koray Akdoğan 《Journal of the American Ceramic Society》2023,106(7):4399-4410

Stereolithography of ceramics remains one of the most powerful additive manufacturing routes for the creation of intricate ceramic parts. Despite its utility as a forming tool, ceramic stereolithography requires a challenging debinding stage due to the requisite high polymeric loading. Earlier research has identified both the polymeric resin composition and debinding atmosphere to be crucial factors in improving debinding performance. Here, we use a combination of thermogravimetric analysis and neutron imaging to examine samples of different compositions printed using the same processing and exposure parameters. We quantify the influence of both polyethylene glycol addition and the use of different debinding atmospheres (argon and vacuum) on the debinding behavior of ceramic pellets. Specifically, we demonstrate a method for examining the concentration gradients that develop during thermal debinding with the aid of neutron tomography. We find that at a constant heating rate of 1°C/min up to 500°C, vacuum atmosphere appears to result in a greater number of cracks as compared to the use of argon. The vacuum atmosphere led to the development of lower concentration gradients in the samples on average. The greatest improvement resulted with the addition of polyethylene glycol to the samples. This addition led to significantly less cracking and much lower concentration gradients in samples during debinding. These results prompt us to conclude that while keeping printing and exposure parameters constant, composition modification has a more significant effect on the debinding improvement than heating atmosphere.  相似文献   

    

Imran Khan  Salman Khan  Shiuan-Yau Wu  Hsin-Tsung Chen  Amir Zada  Liu Linlin  Ahmed Ismail  Sharafat Ali  Fazal Raziq  Mustafa Haider  Javid Khan  Sami Ullah  Shin-pon Ju  Shiliang Wang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(25):2208179

The realization of solar-light-driven CO₂ reduction reactions (CO₂ RR) is essential for the commercial development of renewable energy modules and the reduction of global CO₂ emissions. Combining experimental measurements and theoretical calculations, to introduce boron dopants and nitrogen defects in graphitic carbon nitride (g-C₃N₄), sodium borohydride is simply calcined with the mixture of g-C₃N₄ (CN), followed by the introduction of ultrathin Co phthalocyanine through phosphate groups. By strengthening H-bonding interactions, the resultant CoPc/P-BNDCN nanocomposite showed excellent photocatalytic CO₂ reduction activity, releasing 197.76 and 130.32 µmol h⁻¹ g⁻¹ CO and CH₄, respectively, and conveying an unprecedented 10-26-time improvement under visible-light irradiation. The substantial tuning is performed towards the conduction and valance band locations by B-dopants and N-defects to modulate the band structure for significantly accelerated CO₂ RR. Through the use of ultrathin metal phthalocyanine assemblies that have a lot of single-atom sites, this work demonstrates a sustainable approach for achieving effective photocatalytic CO₂ activation. More importantly, the excellent photoactivity is attributed to the fast charge separation via Z-scheme transfer mechanism formed by the universally facile strategy of dimension-matched ultrathin (≈4 nm) metal phthalocyanine-assisted nanocomposites.  相似文献   

    

Yoo Jin Lee  Mustafa K. Abdelrahman  Manivannan Sivaperuman Kalairaj  Taylor H. Ware 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(41):2302774

Materials that undergo reversible changes in form typically require top-down processing to program the microstructure of the material. As a result, it is difficult to program microscale, 3D shape-morphing materials that undergo non-uniaxial deformations. Here, a simple bottom-up fabrication approach to prepare bending microactuators is described. Spontaneous self-assembly of liquid crystal (LC) monomers with controlled chirality within 3D micromold results in a change in molecular orientation across thickness of the microstructure. As a result, heating induces bending in these microactuators. The concentration of chiral dopant is varied to adjust the chirality of the monomer mixture. Liquid crystal elastomer (LCE) microactuators doped with 0.05 wt% of chiral dopant produce needle-shaped actuators that bend from flat to an angle of 27.2 ± 11.3° at 180 °C. Higher concentrations of chiral dopant lead to actuators with reduced bending, and lower concentrations of chiral dopant lead to actuators with poorly controlled bending. Asymmetric molecular alignment inside 3D structure is confirmed by sectioning actuators. Arrays of microactuators that all bend in the same direction can be fabricated if symmetry of geometry of the microstructure is broken. It is envisioned that the new platform to synthesize microstructures can further be applied in soft robotics and biomedical devices.  相似文献   

    

Saba Khanum  Khurram Mustafa 《Concurrency and Computation》2023,35(26):e7835

Every transaction is made public and verified by a third party, and the transparency of blockchain applications leads to privacy leaks. Everyone can access the transaction, making it easier for network analysis to identify the user's identity, which is a major problem with the blockchain. Financial institutions have become hesitant to adopt blockchain technology; as a result, preventing its spread. To confirm that encryption and security are maintained for transactions in the blockchain, this research introduces a zero-knowledge proof (ZKP) based transaction validation scheme. To increase the security of blockchain applications, the proposed lattice-based blind ring signature (LBRS) scheme integrates blind and ring signatures and is applied to sensitive data. The data are encrypted using this encryption scheme before being stored with the transactional information in the blocks. The encrypted data is then stored in the blocks, which users can retrieve after verification. The encrypted data is then stored in blocks, which users can retrieve after verification. A verification scheme based on the ZKP is used to prevent unauthorized access and changes to the data. The proposed LBRS scheme meets the security analysis requirement. The performance of an LBRS scheme is compared to other relevant models in terms of execution time, encryption time, and decryption time. Overall, the results are more encouraging and reassuring than other relevant works of interest. Finally, this model provides better computational security and satisfies the requirements like correctness and security analysis.  相似文献   

Do matrix metalloproteinase inhibitors improve the bond durability of universal dental adhesives?     

Neslihan Tekçe  Safa Tuncer  Mustafa Demirci  Sibel Balci 《Scanning》2016,38(6):535-544

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Hasan Ozturk  Ahmed Yashar  Mustafa Sabuncu 《先进材料力学与结构力学》2016,23(6):715-726

The effects of crack depth and crack location on the in-plane static and dynamic stability of cracked multi-bay frame structures subjected to periodic loading have been investigated numerically by using the finite element method. For the rectangular cross-section beam, a crack element is developed by using the principles of fracture mechanics. In addition, the effect of the number of spans and static and dynamic load parameters on static and dynamic stability analysis are also investigated. For buckling and dynamic stability analyses, the results obtained by using the present model are presented in three-dimensional graphical forms and tables.  相似文献   

    

Khaled H. Ibrahim  Mehrdad Irannejad  Mojtaba Hajialamdari  Ali Ramadhan  Kevin P. Musselman  Joseph Sanderson  Mustafa Yavuz 《Advanced Materials Interfaces》2016,3(14)

Graphene and its functionalized derivatives are unique and multifaceted novel materials with a wide range of applications in chemistry, healthcare, and optoelectronic engineering. 3D graphene materials exhibit several advantages over 2D (monolayer) graphene for a variety of devices applications. Here a novel and effective room temperature technique is introduced to convert an aqueous graphene oxide solution into a reduced graphene oxide gel with tunable physical and chemical properties comparable to a monolayer graphene sheet, without the need for any additives or chemical agents. The femtogel is synthesized by exposing an ultrahigh concentration graphene oxide solution with single‐layer flakes to high intensity femtosecond laser pulses. The femtosecond laser beam is focused on the air/aqueous solution interface to enhance the vaporization of functional groups and water, enabling femtogel formation. By controlling the pulsed laser intensity, beam focal parameters, and pulse duration, it is possible to produce several milliliters of femtogel in as little as 8 min. Through initial optimization of the irradiation parameters, a thin film is produced from a femtogel that demonstrates a surface roughness less than 6 nm, and more than 95% reduction in OH absorbance, as compared to a thin film produced from the unexposed graphene oxide solution.  相似文献   

    

Noha I. A. Mutwali  Abdelmoniem I. Mustafa  Yasir S. A. Gorafi  Isam A. Mohamed Ahmed 《Food Science & Nutrition》2016,4(4):508-520

To meet the increased demand for wheat consumption, wheat cultivation in Sudan expanded southward to latitudes lower than 15°N, entering a new and warmer environment. Consequently, wheat breeders developed several wheat genotypes with high yields under these environmental conditions; however, the evaluation of the end‐use quality of these genotypes is scarce. In this study, we assessed the end‐use quality attributes of 20 wheat genotypes grown in three different environments in the Sudan (Wad Medani, Hudeiba, and Dongola). The results showed significant differences (P ≤ 0.01) in all quality tests among environments, genotypes and genotypes Versus environments. The findings obtained, covered wide ranges of test weight (TW, 76.6–85.25 kg/hL), thousand kernel weight (TKW, 28.70–48.48 g), protein (PC, 9.96–14.06%), wet gluten (WG, 28.63–46.53%), gluten index (GI, 36.36–92.77%), water holding capacity (WHC, 168.42–219.32%), falling number (FN, 508.00–974.67 sec), and sedimentation value (SV, 19.00–40.00 mL). Analysis of the traits, genotypes, and traits versus genotypes showed varied correlations in the three growing environments. The genotype G3 grown in either one or all of the three environments exhibits worthy performance and stability for most of the tested quality traits. The crossing of this genotype with high yield genotypes could produce cultivars with sufficient quality and marketability.  相似文献