Effect of mixing state of raw materials in the preparation of Mg2B2O5 whiskers

Morphology preservation and crystallinity improvement in the thermal conversion of the hydrothermal synthesized MgBO2(OH) nanowhiskers to Mg2B2O5 nanowhiskers

“…S3) demonstrated that the dehydration of MgBO 2 (OH) nanowhiskers and subsequent recrystallization (650-700 1C) resulted in somewhat shorter and thinner Mg 2 B 2 O 5 nanowhiskers with lower aspect ratio as a result of the shrinkage of the mesopores. It is worth noting that, since hydrothermal technique was introduced into the synthesis of Mg 2 B 2 O 5 1D nanostructures, the advantages of hydrothermal processing such as energy saving (200-350 1C of decrease in reaction temperature) and moderate experimental conditions (easy control and no need of any catalyst) were well transmitted down via the appropriate selection of calcination temperature, precise control of the heating rate and procedure, compared with 1D nanostructured Mg 2 B 2 O 5 , derived from other traditional methods [36][37][38][39][40][41].…”

“…1D nanostructured magnesium borates, including MgB 4 O 7 nanowires [33], Mg 3 B 2 O 6 nanotubes [34] and nanobelts [35], Mg 2 B 2 O 5 nanowires [36,37], nanorods [38] and whiskers [39][40][41], etc., have been paid much attention in recent years for their wide usage as reinforcing components in the electronic ceramics [33], the wide band gap semiconductors [36], the antiwear additive [37], and the plastics or the aluminum/magnesium [41] matrix alloys. In contrast, 1D Mg 2 B 2 O 5 nanomaterials [36][37][38][39][40][41] have attracted more research interests for their wider applications.…”

“…In contrast, 1D Mg 2 B 2 O 5 nanomaterials [36][37][38][39][40][41] have attracted more research interests for their wider applications. Traditionally, 1D micro-/nanostructured magnesium borates were prepared at relatively high temperature within 850-1250 1C via thermal evaporation or CVD technique [33][34][35][36][37][38], flux method [39][40][41], or supercritical method (500-600 1C, 200-1000 bar, 14 days) [42].…”

“…In contrast, 1D Mg 2 B 2 O 5 nanomaterials [36][37][38][39][40][41] have attracted more research interests for their wider applications. Traditionally, 1D micro-/nanostructured magnesium borates were prepared at relatively high temperature within 850-1250 1C via thermal evaporation or CVD technique [33][34][35][36][37][38], flux method [39][40][41], or supercritical method (500-600 1C, 200-1000 bar, 14 days) [42]. Although the 1D Mg 2 B 2 O 5 nanostructures synthesized by the above methods exhibited high crystallinity, problems such as high temperature accompanied by high energy consumption, the coexistence of the particulate agglomerates [33,35,[39][40][41] and the relatively rigorous experimental conditions [34,36,42] still needed to be solved.…”

Influence of process parameters on hydrothermal formation of magnesium borate hydroxide nanowhiskers

“…[4][5][6] Traditionally, Mg 2 B 2 O 5 whiskers could be prepared by the flux method using MgO/MgCl 2 , H 3 BO 3 , KOH/ NaOH as the raw materials and KCl/NaCl as the flux, but the existence of the agglomerate byproduct and the high energy consumption limited its practical utilisation. 6,7 In contrast, hydrothermal synthesis has shown some distinct advantages in preparing uniform micro/ nanocrystals with high crystallinity and high purity, such as the moderate experimental conditions and the easy control of the process parameters. [8][9][10][11][12] It was reported that fibrous Mg 2 B 2 O 5 was formed under a supercritical condition (500-600uC, 20-100 MPa, 336 h) using H 3 BO 3 , MgCO 3 as the reactants and NaCl as the mineraliser.…”