Cold crystallization of poly(L-lactic acid) (PLLA) from amorphous state on highly oriented polyethylene (PE) substrate has been studied by electron diffraction and infrared spectroscopy. Both electron diffraction and infrared spectroscopy analyses show that the PLLA in the as-prepared PLLA/PE double layers is in the amorphous state. Annealing of the as-prepared PLLA/PE samples at 130 °C leads to the cold crystallization of PLLA. It is confirmed that the PLLA grown on the oriented PE surface exhibits high orientation with molecular chains aligned perpendicular the chain direction of PE, indicating the occurrence of heteroepitaxy of PLLA on the PE substrate. This provides a first example of perpendicular chain orientation of polymer epitaxy. Moreover, it demonstrates the capability of polymer epitaxy from amorphous state through annealing. Infrared spectroscopy analysis on the as-prepared PLLA/PE double layers shows that the orientation of PLLA molecules in contact with the PE substrate exists already in the amorphous state. It is these oriented PLLA chains in amorphous phase that transform into crystal nuclei during cold crystallization and initiate the oriented overgrowth of PLLA on the PE substrate.

Solar‐driven evaporation is a promising way of using abundant solar energy for desalinating polluted water or seawater, which addresses the challenge of global fresh water scarcity. Cost‐effectiveness and durability are key factors for practical solar‐driven evaporation technology. The present cutting‐edge techniques mostly rely on costly and complex fabricated nanomaterials, such as metallic nanoparticles, nanotubes, nanoporous hydrogels, graphene, and graphene derivatives. Herein, a black nylon fiber (BNF) flocking board with a vertically aligned array prepared via a convenient electrostatic flocking technique is reported, presenting an extremely high solar absorbance (99.6%), a water self‐supply capability, and a unique salt self‐dissolution capability for seawater desalination. Through a carefully designed 3D structure, a plug‐in‐type BNF flocking board steam generator realizes a high evaporation rate of 2.09 kg m−2 h−1 under 1 kW m−2 solar illumination, well beyond its corresponding upper limit of 1.50 kg m−2 h−1 (assuming 100% solar energy is being used for evaporation latent heat). With the advantages of high‐efficiency fabrication, cost‐effectiveness, high evaporation rate, and high endurance in seawater desalination, this 3D design provides a new strategy to build up an economic, sustainable, and rapid solar‐driven steam generation system.

Radiant heating, as a significant thermal management technique, is best known for its high thermal effect, media-free operation, good penetration, and compatibility for different heated shapes. To promote sustainable development in this area, developing advanced infrared radiation material is in high demand. In this work, a lightweight, flexible dual-emitter infrared electrothermal material, graphene glass fiber (GGF), is developed by chemical vapor deposition (CVD) method, with both graphene and glass fiber as the radiation elements. Large-area GGF fabric (GGFF) exhibits wavelength-independent high infrared emissivity (0.92) and thermal radiation efficiency (79.4%), as well as ultrafast electrothermal response (190.7 °C s–1 at 9.30 W cm–2) and uniform heating temperature. The superior radiant heating capability of GGFF to traditional alloy heating wires can achieve 33.3% energy saving. GGF can promote the development of efficient and energy-saving heat management technology.

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