The various forms of cellulose-based materials possess high mechanical and thermal stabilities, as well as three-dimensional open network structures with high aspect ratios capable of incorporating other materials to produce composites for a wide range of applications. Being the most prevalent natural biopolymer on the Earth, cellulose has been used as a renewable replacement for many plastic and metal substrates, in order to diminish pollutant residues in the environment. As a result, the design and development of green technological applications of cellulose and its derivatives has become a key principle of ecological sustainability. Recently, cellulose-based mesoporous structures, flexible thin films, fibers, and three-dimensional networks have been developed for use as substrates in which conductive materials can be loaded for a wide range of energy conversion and energy conservation applications. The present article provides an overview of the recent advancements in the preparation of cellulose-based composites synthesized by combining metal/semiconductor nanoparticles, organic polymers, and metal-organic frameworks with cellulose. To begin, a brief review of cellulosic materials is given, with emphasis on their properties and processing methods. Further sections focus on the integration of cellulose-based flexible substrates or three-dimensional structures into energy conversion devices, such as photovoltaic solar cells, triboelectric generators, piezoelectric generators, thermoelectric generators, as well as sensors. The review also highlights the uses of cellulose-based composites in the separators, electrolytes, binders, and electrodes of energy conservation devices such as lithium-ion batteries. Moreover, the use of cellulose-based electrodes in water splitting for hydrogen generation is discussed. In the final section, we propose the underlying challenges and outlook for the field of cellulose-based composite materials.

Photosensitive polymers or dielectric materials such as polyimides have been used in fan-out wafer-level packaging process (FOWLP) as a redistribution layer for quite some time. In the condensed 2D and 3D packaging processes, the dielectric materials are applied multiple times to create as many as four or five redistribution layers. At the end of the process, the first layer may experience up to four times of heat cycles in which the polymer properties may change. However, the effect of heat cycles on properties of dielectric film as well as their contributions to the wafer-level warpage is still unclear. To understand the changes of materials’ properties after several heat cycles, the thermal and thermo-mechanical properties of negative-tone and positive-tone types of dielectric films are characterized by using the Thermomechanical Analysis (TMA), Dynamic Mechanical Analysis (DMA), and Thermogravimetric Analysis (TGA). The glass transition temperature (Tg), coefficient of linear thermal expansion (CTE), and modulus (storage, E′ and loss, E²) are analyzed and compared. In addition, the morphology of the films before and after heat cycles are also analyzed.

In the present work, the effect of incorporating boron nitride nanosheets (denoted as BNNSs in this paper) in a commercial epoxy molding compound (EMC) that has been used in fan-out wafer-level packaging (FOWLP) is investigated. The BNNSs were produced by exfoliating hexagonal boron nitride (h-BN) in water and were incorporated in EMC without any surface modification. BNNS-reinforced EMCs were prepared by adding various concentrations of BNNSs in the pristine EMC, followed by thermal curing. The characterization of nanocomposite samples implies that the epoxy-hardener reaction is not significantly affected by the presence of BNNSs. Surprisingly, EMCs containing low concentrations of BNNSs showed better thermal stability and thermomechanical properties when compared with the pristine EMC. Meanwhile, sample with the highest concentration of BNNSs performed poorly, which could be due to the BNNS agglomeration and filler/polymer phase separation. This method is a simple and inexpensive way to alter the mechanical properties of commercial EMCs. The tunability of material properties is foreseen to broaden the materials of choice for FOWLP, support product customization and tackle the warpage issue in FOWLP from the material engineering perspective.

Carbon fiber-reinforced polymer (CFRP) composites are highly functional composites which comprise two major components: the polymer matrix and the carbon fiber. Lightweight and having high strength, CFRPs have been used heavily in various industries such as wind, aerospace and automobile. The increasing demand and extensive use led to a huge quantum of CFRP waste from both end-of-life and during manufacturing. Out of this waste, only 2% is recycled, the rest are disposed of via incineration and/or landfill. This has raised significant environmental and sustainability concerns. The current state-of-the-art way of recycling CFRPs is by pyrolysis. However, through the pyrolysis process, the polymer used in the CFRPs, which accounts for around 65–75 wt.%, cannot be recovered and reused. In most publications, the focus on CFRP recycling was on the recovering of the more valuable carbon fiber. The polymer matrix is mostly burnt off, in the case of pyrolysis, or disposed. To obtain full circularity, recovering and reusing both the carbon fiber and polymer is necessary. In this paper, we primarily focus on the recovered bisphenol-A type of epoxy polymer (REP) obtained from solvolysis digestion of CFRP and explore the feasibility of reusing this REP by blending it with pristine epoxy in various compositions to create new materials. The physical and mechanical properties, including decomposition temperatures (T_d), glass transition temperatures (T_g), storage modulus, loss modulus, flexural and tensile strength, were characterized using thermal gravity analyzer (TGA), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA) and Instron universal tester. The results indicate a decrease in glass transition and decomposition temperature, and mechanical properties as the blending composition increases. This suggests that the total blending composition should not exceed 10 wt.%, with an optimal range potentially falling between 5 to 6 wt.%.