Recycled, Bio-Based, and Blended Composite Materials for 3D Printing Filament: Pros and Cons—A Review

In recent years, additive manufacturing (AM), known as “3D printing”, has experienced exceptional growth thanks to the development of mechatronics and materials science. Fused filament deposition (FDM) manufacturing is the most widely used technique in the field of AM, due to low operating and material costs. However, the materials commonly used for this technology are virgin thermoplastics. It is worth noting a considerable amount of waste exists due to failed print and disposable prototypes. In this regard, using green and sustainable materials is essential to limit the impact on the environment. The recycled, bio-based, and blended recycled materials are therefore a potential approach for 3D printing. In contrast, the lack of understanding of the mechanism of interlayer adhesion and the degradation of materials for FDM printing has posed a major challenge for these green materials. This paper provides an overview of the FDM technique and material requirements for 3D printing filaments. The main objective is to highlight the advantages and disadvantages of using recycled, bio-based, and blended materials based on thermoplastics for 3D printing filaments. In this work, solutions to improve the mechanical properties of 3D printing parts before, during, and after the printing process are pointed out. This paper provides an overview on choosing which materials and solutions depend on the specific application purposes. Moreover, research gaps and opportunities are mentioned in the discussion and conclusions sections of this study.

Computational and conceptual blends: Material considerations and agency in a multi-material design workflow

The assimilation of functionally graded (or multi-) materials into architecture is deemed to enable the rethinking of current architectural design practice and bring back material considerations at the heart of the early design process. In response, the paper outlines a functionally graded material (FGM) design workflow that departs from standard early-stage CAD, which is typically performed via computer elements devoid of materiality. It then analyses this workflow from a theoretical perspective, namely through Edwin Hutchins’ materially anchored conceptual blending, Lambros Malafouris’ Material Engagement Theory (MET) and John Searle’s concepts of intentionality. The aim is to demonstrate that due to the superimposition of material considerations that precede and succeed the CAD operation, working with material-less entities during early-stage FGM design is not logically sustainable. Additionally, multi-materiality allows for the questioning of authorship in the design process and leads to a repositioning of agency from the subject to the locus of engagement with digital materials and their affordances.

Hydrometallurgical recovery of lithium carbonate and iron phosphate from blended cathode materials of spent lithium-ion battery

The recycling of cathode materials from spent lithium-ion battery has attracted extensive attention,but few research have focused on spent blended cathode materials.In reality,the blended materials of lithium iron phosphate and ternary are widely used in electric vehicles,so it is critical to design an effective recycling technique.In this study,an efficient method for recovering Li and Fe from the blended cathode materials of spent LiFePO_(4)and LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)batteries is proposed.First,87%A1 was removed by alkali leaching.Then,91.65%Li,72.08%Ni,64.6%Co and 71.66%Mn were further separated by selective leaching with H_(2)SO_(4)and H_(2)O_(2).Li,Ni,Co and Mn in solution were recovered in the form of Li_(2)CO_(3)and hydroxide respectively.Subsequently,98.38%Fe was leached from the residue by two stage process,and it is recovered as FePO_(4)·2H_(2)O with a purity of 99.5%by precipitation.Fe and P were present in FePO_(4)·2H_(2)O in amounts of 28.34%and 15.98%,respectively.Additionally,the drift and control of various components were discussed,and cost-benefit analysis was used to assess the feasibility of potential application.

Small Molecule:Polymer Blends for N-type Organic Thin Film Transistors via Bar-coating in Air

Fabricating n-type organic thin film transistors(OTFTs)based on small molecules via solution processing under atmospheric conditions remains challenging.Blending small molecules with polymer is an effective strategy to improve the solution processibility and air stability of the resulted devices.In this study,polystyrene was chosen to blend with n-type small molecule DPP1012-4F to enhance the continuity of the semiconductor layer and maintain a favorable edge-on stacking of semiconductors.The introduction of high-boiling point 1-chloronaphthalene as a solvent additive in the blending system can reduce the grain boundary defects in the microscopic morphology.These changes in aggregation behavior are confirmed by X-ray diffraction,atomic force microscopy and polarized optical microscopy analyses.Via bar-coating of the semiconductor layers in air,the electron mobility of the resulted OTFTs under the optimal condition is 0.73 cm2·V–1·s–1,which is amongst the highest n-type small molecule-based OTFTs with active layers prepared in air up to now.These results show a great potential of the blending strategy in industrial roll-to-roll manufacture of high-mobility n-type OTFTs.