Nowadays, fossil fuels are used in a clearly unsustainable way that can bring potentially catastrophic consequences. Electricity is currently delivered to end users by generation and energy transmission companies. Previous research shows that the development of modern circular economy sets a need for the re-orientation of socio and economic development of decentralized systems, including energy basis. In addition to being ecological, the use of renewable energy sources also has economic significance by contributing to energy independence. Citizens, industries, local and national authorities become interconnected within emerging novel renewable energy sourcing communities, through which they establish trade of energy and, most importantly, models of investing and reshaping the distribution of renewable energy. The modern portfolio management of renewable energy networking is aiming toward decentralized systems of trade, where the consumer becomes a producer (prosumer) within the network, itself managed by users. Excess energy produced in the micro-grid nets within the over-arching national and transnational energy grid should be accounted for and managed with blockchain technology for financial and structural security. The decentralization of the energy market requires the establishment of strict norms that will regulate the market and taxation of profits arising. The extensive literature review on blockchain in the energy sector reflects a very pragmatic and narrow approach to the topic, although it is evident that the distribution of energy within the blockchain would enable economic development through reducing cost and ensuring more secure energy trade. Blockchain technology embeds the related digital codes, in which information will be visible to all, but also secured from hacking and duplicating. However, there are challenges to this paradigm, not least the energy consumption of the extensive nodal mesh required to perform the necessary protocols. This paper aims to provide an overview of the application of blockchain technology and the need for the development of the regulatory system and of potential solutions to the challenges posed. By undertaking an energy consumption analysis of blockchain implementation from first electronic principles, which has not been constructed before in the literature, this paper’s conclusion stresses the future demand for reducing energy consumption and considers the latest findings in the quantum coupling of light signals as a potential for solving the enormous ledger duplication structure problem.

Nano-lignocellulose (NLC) and lignin-free nanocellulose (nano-holocellulose, NHC) were used in paper coating to investigate their effect on coating layer quality and offset printing. The NLC was produced by microfluidisation of unbleached secondary fibres while the reference NHC was obtained from the same fibre source after lignin removal (OHE_PH bleaching), following the same mechanical process. TEMPO-mediated oxidation of the fibres prior to microfluidisation was applied to increase the electrostatic charge and hydrophilicity of the nanofibrils. The coatings, displaying given surface morphology and energy, were applied on Kraft, printing-grade papers at three grammage levels. The structure of the coated and uncoated (reference) papers were accessed (SEM and AFM) and IGT printing was carried out to determine the print density, print gloss, rub-off resistance, surface energy, roughness, ink transfer, dry pick resistance, water interference and set-off. The results highlight the important effect of residual lignin or type of nanocellulose on the coating layer and the development of offset printing properties. It was observed that roughness was a key factor leading to a deterioration of the print properties, predominantly affecting the NLC coating. Considering the lower hydrophilicity of NLC, an alternative dispersion with water-alcohol mixtures is proposed. By using this dispersing medium, tailorable surface coverage, surface smoothness, ink acceptance and improved printability was achieved. We show that under these conditions and compared to NHC, NLC is equally effective as a coating layer.

In previous investigations, it was found that the thermal properties of a polyamide 12 compound can be manipulated, using a designed filler, to improve the melting as well as crystallization behavior, determined for selective laser sintering. A common downside of the introduction of a non-flexing mineral filler is the reduction of the mechanical properties, such as ductility. This paper investigates the influence of content and surface modification of limestone on the mechanical properties. The aim is to understand the effect of an optimized coupling agent on the properties of a compound, containing polyamide 12 filled with 10 wt % of surface modified calcium carbonate. A range of four mineral filler modifications was chosen to investigate their coupling effect, namely 6-amino hexanoic acid, ε-caprolactam, l-arginine or glutamic acid. The in advance surface modified fillers were then each used in combination with the polyamide 12 in a twin-screw extrusion process. With an optimized surface modifying agent, the tensile strength as well as elongation at break can be improved in comparison with uncoated filler implementation, such that up to 60% of the loss of ductility and toughness of a final part when using an untreated filler could be regained using an optimized surface modifier at a correct amount. With the tested filler grade and the specific tested filler amount, the optimized amount of 6-amino hexanoic acid was approx. 2.5 mmol of treatment agent per 100 m² of CaCO₃. These found improvements in a twin-screw extruded polyamide 12 compound show the possible usage of modified calcium carbonate as a functional filler in additive manufacturing and can potentially be transferred in a subsequent investigation in the selective laser sintering process.

Adjusting the thermal response properties of a polymeric compound can significantly improve the usability in a selective laser-sintering process. As previously shown, combining a precise amount of coarse and narrow size distribution fine calcium carbonate fillers results in a potential optimization of the thermal properties of a polyamide 12 matrix. Additionally, up to 60% of the normally associated lost ductility can be re-gained by surface modification, thus functionalizing the filler. To optimize the functionality further this study combines a precisely defined particle size ratio of fillers adopting a specially selected surface modification using amino hexanoic acid. Morphology of the carbonate filler was also investigated. The range of effect of each parameter on the thermal response and mechanical properties was studied. The results show that the thermal properties have large potential to be optimized, without reducing the ductility significantly, by adjusting the morphology and size ratio of coarse and fine filler particles. The compound properties were demonstrated using a twin-screw extruder, indicating the potential for producing a preparate composite for additive manufacturing.

Ionic liquid 1-butyl-3-methylimidazolium chloride [BMIM][Cl] was used to prepare cellulose (CELL), cellulose/polycaprolactone (CELL/PCL), cellulose/polycaprolactone/keratin (CELL/PCL/KER), and cellulose/polycaprolactone/keratin/ground calcium carbonate (CELL/PCL/KER/GCC) biodegradable mulch films. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy, optical microscopy, and Field-Emission Scanning Electron Microscopy (FE-SEM) were used to verify the films’ surface chemistry and morphology. Mulch film made of only cellulose regenerated from ionic liquid solution exhibited the highest tensile strength (75.3 ± 2.1 MPa) and modulus of elasticity of 944.4 ± 2.0 MPa. Among samples containing PCL, CELL/PCL/KER/GCC is characterized by the highest tensile strength (15.8 ± 0.4 MPa) and modulus of elasticity (687.5 ± 16.6 MPa). The film’s breaking strain decreased for all samples containing PCL upon the addition of KER and KER/GCC. The melting temperature of pure PCL is 62.3 °C, whereas that of CELL/PCL film has a slight tendency for melting point depression (61.0 °C), which is a characteristic of partially miscible polymer blends. Furthermore, Differential Scanning Calorimetry (DSC) analysis revealed that the addition of KER or KER/GCC to CELL/PCL films resulted in an increment in melting temperature from 61.0 to 62.6 and 68.9 °C and an improvement in sample crystallinity by 2.2 and 3.0 times, respectively. The light transmittance of all studied samples was greater than 60%. The reported method for mulch film preparation is green and recyclable ([BMIM][Cl] can be recovered), and the inclusion of KER derived by extraction from waste chicken feathers enables conversion to organic biofertilizer. The findings of this study contribute to sustainable agriculture by providing nutrients that enhance the growth rate of plants, and hence food production, while reducing environmental pressure. The addition of GCC furthermore provides a source of Ca²⁺ for plant micronutrition and a supplementary control of soil pH.

It has been a persistent challenge to develop eco-friendly packaging cellulose film providing the required multiple barrier properties whilst simultaneously contributing to a circular economy. Typically, a cellulosic film made from nanocellulose materials presents severe limitations, such as poor water/moisture resistance and lacking water vapour barrier properties, related primarily to the hydrophilic and hygroscopic nature of cellulose. In this work, alkyl ketene dimer (AKD) and starch, both eco-friendly, non-toxic, cost-effective materials, were used to achieve barrier properties of novel cellulose–calcium carbonate composite films regenerated from paper components, including paper waste, using ionic liquid as solvent. AKD and starch were applied first into the ionic cellulose solution dope mix, and secondly, AKD alone was coated from hot aqueous suspension onto the film surface using a substrate surface precooling technique. The interactions between the AKD and cellulose film were characterised by Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) showing the formation of a ketone ester structure between AKD and the hydroxyl groups of cellulose. The presence of calcium carbonate particles in the composite was seen to enhance the cellulose crystallinity. The initial high-water vapour and oxygen transmission rates of the untreated base films could be decreased significantly from 2.00 to 0.14 g m⁻² d⁻¹, and 3.85 × 10² to 0.45 × 10² cm³ m⁻² d⁻¹, respectively. In addition, by applying subsequent heat treatment to the AKD coating, the water contact angle was markedly increased to reach levels of superhydrophobicity (>150°, and roll-off angle < 5°). The resistance to water absorption, grease-permeation, and tensile strength properties were ultimately improved by 41.52%, 95.33%, and 127.33%, respectively, compared with those of an untreated pure cellulose film. The resulting regenerated cellulose–calcium carbonate composite-based film and coating formulation can be considered to provide a future bio-based circular economy barrier film, for example, for the packaging, construction and agriculture industries, to complement or replace oil-based plastics.