Laccase-assisted approach to graft multifunctional materials of interest: keratin-EC based novel composites and their characterisation

This study focuses on the evaluation of raw keratin as a potential material to develop composites with novel characteristics. Herein, we report a mild and eco-friendly fabrication of in-house extracted feather keratin-based novel enzyme assisted composites consisting of ethyl cellulose (EC) as a backbone material. A range of composites between keratin and EC using different keratin: EC ratios were prepared and characterised. Comparing keratin to the composites, the FT-IR peak at 1,630 cm-1 shifted to a lower wavenumber of 1,610 cm-1 in keratin-EC which typically indicates the involvement of β-sheet structures of the keratin during the graft formation process. SEM analysis revealed that the uniform dispersion of the keratin increases the area of keratin-EC contact which further contributes to the efficient functionality of the resulting composites. In comparison to the pristine keratin and EC, a clear shift in the XRD peaks was also observed at the specific region of 2-Theta values of keratin-g-EC. The thermo- mechanical properties of the composites reached their highest levels in comparison to the keratin which was too fragile to be measured for its mechanical properties. Considerable improvement in the water contact angle and surface tension properties was also recorded.

Laccase-assisted bio-grafting of polyhydroxy-alkanoates (PHAs) onto the ethyl cellulose (EC) backbone

In the present study, a novel enzyme-based methodology for grafting Polyhydroxyalkanoates (PHAs) onto the ethyl cellulose (EC) as a backbone polymer was developed. Laccase assisted copolymerization was carried out under mild and eco-friendly reaction conditions. The resulting homogeneous composite membranes were characterized by Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Atomic Force Microscopy (AFM). The FTIR spectra of pure PHAs and PHAs containing graft composites (PHAs-g-EC) showed their strong characteristic bands at 1721 cm1, 1651 cm-1 and 1603 cm-1 respectively. Other accompanying bands in the range of 900-1300 cm-1 correspond to C=O vibration and C-O-C bond stretching, which could be contributed from PHAs and EC, respectively. The high intensity of the 3358 cm-1 band in the graft composite may have corresponded to the degradation of the carboxylic group from PHAs and also showed an increase of hydrogen-bonded groups at that distinct band region. The morphology was examined by SEM, which showed the well dispersed PHAs crystals in the backbone polymer of EC. XRD pattern for PHAs showed distinct peaks at 2-Theta values of 28o, 32o, 34o, 39o, 46o, 57o, 64o, 78o and 84o that represent the crystalline nature of PHAs. In comparison with those of neat PHAs, the degree of crystallinity for PHAs-g-EC decreased and this reduction is mainly because of the new cross-linking of PHAs within the EC backbone that changes the morphology and destroys the crystallites. Improved mechanical properties were observed for the PHAs-g-EC as compared to the individual components due to the impregnation of EC as reinforcement into the PHAs matrix. Improved mechanical strength enhanced thermal properties, along with low crystallinity of the present PHAs-g-EC suggesting its potential for various industrial and bio-medical applications.

Durkheim, ethnography and suicide: researching young male suicide in the transnational London Alevi-Kurdish community

This study of the unusually high incidence of young male suicides in the transnational Alevi-Kurdish community in London, demonstrates the benefits of combining a Durkheimian structural approach with a qualitatively driven ethnographic methodology. Examination of the life experiences of those who committed suicide is located within the underlying social organization of the transnational community in which the suicides occurred, enabling us to explore unanticipated events that render certain groups more at risk of committing suicide. Interviews with significant others facilitated a deeper understanding of the personal life paths of those who committed suicide. The suicide cases followed a particular assimilation trajectory that gradually positioned them in a “rainbow underclass”, an anomic social position leading to suicide. Despite the sensitivity of the subject, participants appreciated the opportunity to discuss their experience frankly and contribute towards a better understanding of the underlying causes in a desperate attempt to prevent further suicides.

Cosmopolitanism and the relevance of ‘zombie concepts’: the case of anomic suicide amongst Alevi Kurd youth

Against Beck’s claims that conventional sociological concepts and categories are zombie categories, this paper argues that Durkheim’s theoretical framework in which suicide is a symptom of an anomic state of society can help us understand the diversity of trajectories that transnational migrants follow and that shape their suicide rates within a cosmopolitan society. Drawing on ethnographic data collected on eight suicides and three attempted suicide cases of second-generation male Alevi Kurdish migrants living in London, this article explains the impact of segmented assimilation/adaptation trajectories on the incidence of suicide and how their membership of a ‘new rainbow underclass’, as a manifestation of cosmopolitan society, is itself an anomic social position with a lack of integration and regulation.