Materials Technology Reports

A study of the underlying dynamics of phase-space projection of microwave-assisted synthesis of transition metal nanostructures

Victor J. Law, Denis P. Dowling — Thu, 02 Jan 2025 08:48:40 +0000

The study brings together in a single publication the phase-space projection analysis of microwave-assisted synthesis of transition monometallic (palladium, silver, platinum, and gold), binary zinc oxide, and metals supported on carbon framework nanostructures. It is shown for a database of fifty microwave-assisted syntheses, a two-variable power-law signature (y = cxn) over four orders of magnitude. The purpose of this study is therefore to identify the underlying dynamics of the power-law signature. A dual allometry test is used to discriminate between transition metal period and row, and between recommended Green Chemistry, problematic Green Chemistry, and non-Green Chemistry hazardous solvents. Typically, recommended Green Chemistry exhibits a broad y-axis distribution within an upper exponent = 1 and lower exponent = 0.5. Problematic Green Chemistry exhibits a y-axes narrower distribution with an upper exponent = 0.94 and a lower exponent = 0.64. Non-Green Chemistry hazardous data shows a further narrowing of the y-axis distribution within upper exponent = 0.87 and lower exponent = 0.66. Mass-based environmental factor is used to calculate the ‘Greenness’ of single-step (facile) transition metal synthesis. The power-law signature also exhibits phase transitions associated with microwave applicator type.

Preparation of nascent disentangled ultra-high molecular weight polyethylene based on Ziegler-Natta catalyst

Fri, 17 Jan 2025 01:15:54 +0000

Ziegler-Natta (Z-N) catalysts hold great significance in the industrial production of ultrahigh molecular weight polyethylene (UHMWPE), given that their outstanding efficacy, profound impact on the molecular weight (MW) of UHMWPE, and extensive industrial applications are highly conspicuous. However, the UHMWPE prepared by Z-N catalyst is usually highly entangled. Considering chain entanglement is essential for altering the processability and mechanical characteristics of nascent UHMWPE, the synthesis of disentangled UHMWPE (dis-UHMWPE) is essential for industrial scalability, therefore holding considerable practical importance. This review summarized recent progress in optimizing Z-N catalysts for the synthesis of dis-UHMWPE, providing a comprehensive overview of research advancements, clarifying polymerization settings, linking polymer structure and activity, and introducing design principles for polymerization techniques. Moreover, the overarching objective is to reveal the principles behind material preparation methods and potentiate the application prospects of UHMWPE materials, therein propelling the advancement of related fields.

Graphene—A hello and goodbye

Ayesha Kausar — Thu, 02 Jan 2025 00:00:00 +0000

After years of research, it can be stated that graphene was an initial game changer and jack of all trades in the world of nanotechnology, owing to innumerable structural/physical characteristics and mammoth range of hi-tech applications. Undoubtedly, since the discovery of graphene, it almost ruled all possible nanotechnological fields, from electronics/energy—to—defense/transportation/civil—to—biomedical. Nevertheless, this statement remained no longer valid after the discovery of more erudite nanostructures, like fullerene, quantum dots, and similar nanoparticles. Reasons for today’s technology turns towards tiny symmetrical nanoparticles seem to be the limitations/hinderance for integrating graphene into energy/semiconducting/photonic devices, and subsequent commercialization over past two decades. In this novel perspective report, therefore, we first time critically analyzed the nanotechnological shifts from graphene, yet despite its early promises, towards proficient zero dimensional entities.