**1. Introduction**

Inorganic nanotubes and inorganic fullerene-like (IF) structures of WS2 were first discovered by Tenne *et al.* in 1992 [1], which has opened a challenging field for the synthesis and applications of numerous such layered structures, such as WS2 [1], MoS2 [2,3], BN [4], NiCl2 [5], and *etc.* Various synthesis methods have been reported, such as the microwave treatment of W(CO)6 (Tungsten carbonyl) reacting with H2S (hydrogen sulphide) [6], ultrasonic irradiation of W(CO)6 solution mixed with diphenylmethane and sulphur followed by heating at 800 °C [6], commercial WS2 activation [7], iodine transport method [8], direct pyrolysis of WS4 2í and CTAB (Cetyltrimethyl Ammonium Bromide) [9], and chemical vapour deposition [10]. Recently, IF-WS2 nanoparticles and nanotubes have also been obtained from WCl*n* and WO*x*Cl*<sup>y</sup>* reacting with H2S [11].

These IF-WS2 and IF-MoS2 nanomaterials, in addition to their significant mechanical, biocompatible and electronic properties, are excellent solid lubricants [12–20]. Accordingly, the incorporation of these nanomaterials into a proper matrix in composites will lead to new products with hugely improved physical and mechanical properties. Another extraordinary property of WS2 nanostructures is their superb shock absorbing performance [21–23], which suggests an important field of application in lightweight and high performance protective composites [24]. Such applications will obviously demand large amounts of IF-WS2 supply, however their synthesis was only obtained in gram level at the early stage, which was far too less for any practical work. More recently, Tenne's group has produced such IFs in large quantities by using new high tower reactors [25], hence realising a great industrial level success in nanomaterials. Nevertheless, an alternative, simple, versatile and yet effective process for the synthesis of such novel nanomaterials remains highly desirable.

Therefore, to develop an innovative, simple and scalable technique that is suitable for the continuous manufacture of IF-WS2 nanomaterials becomes the primary aim of this work. From previous studies [25–27], where a deeper understanding of the formation mechanism of IF-WS2 nanoparticles has been gained, it is found that the key technical barriers for scaling up of the IF-WS2 lie in the powder agglomeration and superficial reaction, which occurs inevitably in a static gas–solid reaction. In order to achieve a large quantity manufacturing, effective measures should be taken to overcome these challenges.

This manuscript describes the design and modification of a rotary furnace, and the initial investigations in scaling up manufacturing of IF-WS2 nanoparticles using the rotary furnace. Several processes starting with different precursors have been investigated, of which the gas–solid reaction using WO3 nanoparticles as the precursor was the most efficient technique. The influence of temperature, reaction time, precursor types and reaction gases *etc.* on the synthesis of IF-WS2 nanomaterials will be optimised. A significantly improved batch yield and a continuous process have been achieved.

#### **2. Results and Discussion**
