Yusuf Nur

Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: alpha-CD, beta-CD, and gamma-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 degrees C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order alpha-CD<beta-CD<gamma-CD, the thermal evolution of menthol shifted to higher temperatures, suggesting that the strength of interaction between menthol and the CD cavity is in the order gamma-CD>beta-CD>alpha-CD.

Facile Synthesis of Poly(hydridocarbyne): A Precursor to Diamond and Diamond‐like Ceramics

Polycarbynes have previously been shown to be polymeric precursors to diamond and diamond‐like carbon. Here, we report an incredibly simple method for producing one of these polymers, poly(hydridocarbyne). The method simply requires chloroform, electricity, a solvent and an electrolyte. Since the polymer is soluble, the production of diamond objects of any shape is feasible. It is hoped that the ease of the synthesis will make these types of polymers accessible to scientists from all disciplines and that the potential applications for this material, which range from electrical to biomedical, are finally realized.

Poly(hydridocarbyne) as Highly Processable Insulating Polymer Precursor to Micro/Nanostructures and Graphite Conductors

Carbon-based electronic materials have received much attention since the discovery and elucidation of the properties of the nanotube, fullerene allotropes, and conducting polymers. Amorphous carbon, graphite, graphene, and diamond have also been the topics of intensive research. In accordance with this interest, we herein provide the details of a novel and facile method for synthesis of poly(hydridocarbyne) (PHC), a preceramic carbon polymer reported to undergo a conversion to diamond-like carbon (DLC) upon pyrolysis and also provide electrical characterization after low-temperature processing and pyrolysis of this material. The results indicate that the strongly insulating polymer becomes notably conductive in bulk form upon heating and contains interspersed micro- and nanostructures, which are the subject of ongoing research.

Synthesis of Poly(silyne-co-hydridocarbyne) for Silicon Carbide Production

Pre-ceramic polymers have previously been shown to be polymeric precursors to silicon carbide, diamond and diamond-like carbon. Here, we report the synthesis of a pre-ceramic polymer, poly(silyne-co-hydridocarbyne), which was electrochemically synthesized from one monomer containing both silicon and carbon in its structure. The polymer is soluble in common solvents such as CHCl3, CH2Cl2 and THF. Since the polymer contains both silyne and carbyne on its backbone, it can be easily converted to silicon carbide upon heating under an ambient inert atmosphere, or to SiO2 under ambient air atmosphere. Poly(silyne-co-hydridocarbyne) was characterized with UV/Vis spectroscopy, FTIR, 1H-NMR, GPC and Raman spectroscopy. Conversion of the polymer to SiC ceramic was accomplished by heating at 1000 and 750°C under an argon atmosphere and characterized with optical microscopy, SEM, X-Ray and Raman spectroscopies.

Facile Synthesis of SiO2 From Poly(silyne-co-hydridocarbyne) Preceramic Precursor

Pre-ceramic polymers have previously been known as polymeric precursors that can be converted to silicon carbide, diamond and diamond-like carbon upon heating at ambient inert atmosphere. Here, we report to demonstrate a novel and simple method for the production of crystalline SiO2 ceramic species using a polymeric precursor, which is poly(silyne-co-hydridocarbyne), upon heating under an ambient air atmosphere. The synthesis of both the polymer and the resulting crystalline ceramic is relatively straightforward and unique. All characterization methods such as Raman and X-ray analysis were showed that SiO2 with a different crystal structure is successfully produced at 1000, 750, and 500 °C under an ambient air atmosphere. In addition, the type of produced SiO2 strictly depends on process temperature. The results also showed that the materials are polycrystalline which is evaluated from the comprehensive XRD analysis. SiO2 produced is the mixture of Tridymite-M, syn and Moganite at 1000 °C, the mixture of Coesite and Tridymite at 750 °C, and the mixture of Coesite and amorphous SiO2 at 500 °C.Graphical Abstract

Poly(Hydridocarbyne) as Highly Processable Insulating Polymer Precursor to Micro/Nanostructures and Graphite Conductors

Carbon-based electronic materials have received much attention since the discovery and elucidation of the properties of the nanotube and fullerene allotropes and conducting polymers. Amorphous carbon, graphite, graphene, and diamond have also been the topics of intensive research. In accordance with this interest we herein provide the details of a novel and facile method for synthesis of poly(hydridocarbyne) (PHC), a pre-ceramic carbon polymer reported to undergo a conversion to diamond-like carbon (DLC) upon pyrolysis and also provide electrical characterization after low-temperature processing and pyrolysis of this material. The results indicate that the strongly insulating polymer becomes notably conductive in bulk form upon heating and contains interspersed micro and nanostructures which are the subject of ongoing research.