We have investigated in detail the growth dynamics of gold nanorods with various aspect ratios in different surrounding environments. Surprisingly, a blue shift in the temporal evolution of colloidal gold nanorods in aqueous medium has been observed during the growth of nanorods by UV-visible absorption spectroscopy. The longitudinal surface plasmon resonance peak evolves as soon as the nanorods start to grow from spheres, and the system undergoes a blue shift in the absorption spectra. Although a red-shift is expected as a natural phenomenon during the growth process of all nano-systems, our blue shift observation is regarded as a consequence of competition between the parameters of growth solution and actual growth of nanorods. The growth of nanorods contributes to the red-shift which is hidden under the dominating contribution of the growth solution responsible for the observed massive blue shift. Supplementary material for this article is available.

The influence of the orientation of gold nanorods in different assemblies has been investigated using the Finite Difference Time Domain (FDTD) simulation method. To understand the relative orientation, we vary the size and angle in dimer geometries. Significant effects of plasmon coupling emerged in longitudinal resonances having end-to-end configurations of gold nanorods.The effect of orientational plasmon coupling in dimers gives rise to both bonding and antibonding plasmon modes. Effects of various geometries like primary monomer, dimer, trimer, and tetramer structures have been explored and compared with their higher nanorod ensembles. The asymmetric spectral response in a 4 × 4 gold nanorods array indicates a Fano-like resonance. The variation of gap distance in ordered arrays allowed modulation of the Fano resonance mode. The resonance wavelength and field enhancement of the plasmon modes have been tuned by varying the gap distance, angular orientation, size irregularity between the nanorods, and nanorod numbers in an array. The integrated nanostructures studied here are not only significant for fundamental research but also applications in plasmon-based devices.

Gold nanoparticle assemblies show a strong plasmonic response due to the combined effects of the individual nanoparticles’ plasmon modes. Increasing the number of nanoparticles in structured assemblies leads to significant shifts in the optical and physical properties. We use finite-difference time-domain (FDTD) simulations to analyze the electromagnetic response of structurally ordered gold nanorods in monomer and dimer configurations. The plasmonic coupling between nanorods in monomers or dimers configurations provides a unique technique for tuning the spectrum intensity, spatial distribution and polarization of local electric fields within and surrounding nanostructures. This study shows an exponential coupling behavior when two gold nanorods are assembled in end-to-end and side-by-side dimer configurations with a small separation distance. The maximum electric field in the gaps between adjacent nanorods in end-to-end dimer configuration describes a more significant enhancement factor than the individual gold nanorod. Our FDTD simulation on dimer in end-to-end assembly for small separation distance up to [Formula: see text][Formula: see text]nm can well explain the observed experimental growth dynamics of gold nanorods.

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Purpose A fragmented research field exists on the applications of disruptive technologies like blockchain in supply chain management. Thus, the purpose of this study is to present a systematic review of literature reviews, summarising the applications of blockchain in various kinds and facets of the supply chain to date. Design/methodology/approach The literature search was conducted using Scopus and Web Of Science databases, and reporting was performed using PRISMA guidelines. In total, 43 review papers were identified, and 15 reviews applicable to the study were synthesised. Findings Blockchain technology is still in its infancy; however, it is gaining high utility in supply chain management. The technology is constantly expanding its application base, and it has enormous potential to cut out intermediaries and improve the efficiency of supply chains. Taking a look at the past and the present, the current study explores unexplored research avenues for the future. Research limitations/implications This study provides key insights to academia interested in exploring and advancing the topic. Practical implications This study will benefit practitioners and business managers exercising the potential of such a technology in various industrial contexts. Social implications The outcome of this study has the potential to bring many benefits to society at large. These benefits, if fully realised, could positively impact the society. Originality/value To the best of the authors’ knowledge, this is the first broad systematic review of reviews analysing the information about blockchain applications and implementation in the supply chain. Based on its constructive overview of the review studies published to date, this study contributes to the supply chain management literature by providing a table of reference for future researchers.