Sepiolite Nanocarriers as a Matrix for Controlled Thermal Energy Storage

Abstract

Applying the eutectic hydrated salt (EHS) mixture of Na2HPO4·12H2O and Na2SO4·10H2O in a 1:1 weight ratio as a phase-change material and natural sepiolite nanocarriers as a matrix, the form-stable phase-change composite EHS@sepiolite was fabricated by vacuum impregnation. Due to the high porosity of sepiolite and its nanofibrous structure with internal channels, the effective loading of the phase-change material reached as high as 88 wt %. The melting temperature of the composite was 38.1 °C and its melting enthalpy was 185 J g–1. The crystallinity of the hydrated salt mixture was retained after loading into the sepiolite matrix. The composite demonstrated high stability over 50 heat uptake/release cycles maintaining its melting temperature and melting enthalpy the same. The combination of natural sepiolite nanocarriers and crystallohydrates is a cheap and efficient nanoscale energy storage system with high potential for practical applications and upscaling because of their natural abundance.

Layered nanomaterials for renewable energy generation and storage

“…The combination of natural nanocarriers like sepiolite and crystallohydrates represents an affordable and effective nanoscale energy storage system with significant potential for practical use and scalability due to their natural abundance. 103,104 Aqueous crystallohydrate solutions were prepared and various amounts of sepiolite were added resulting in crystallohydrate/ sepiolite dispersions with different crystallohydrate contents (50, 60, 70, 80, 90%). These dispersions were then subjected to ultrasound treatment at 40 1C for 30 minutes, followed by a 10-minute incubation at room temperature.…”

Preparation of Hybrid Nanopigments with Excellent Environmental Stability, Antibacterial and Antioxidant Properties Based on Monascus Red and Sepiolite by One-Step Grinding Process

“…Compared with APT, Sep is a magnesium hydrosilicate with larger nanochannels (1.06 nm × 0.37 nm) and fibrous morphology, which is also formed by two continuous tetrahedral sheets of silicon oxides linked by discontinuous octahedral sheets of magnesium oxides [11]. The reversal period of the apical oxygen in every three silicate chairs results in the existence of numerous silanol (Si-OH) groups on the surface and the formation of parallel tunnels and channels arranged along the fibers [12,13]. The unique porous structure is filled with weakly bound zeolitic H 2 O that forms the hydrogen bridge with the tetrahedral sheet and with tightly bound structural OH 2 coordinated to the magnesium at the ribbon borders [14,15].…”