Testing of I-Minerals' HalloPure Halloysite Yields Excellent Results

VANCOUVER, BC--(Marketwired - July 28, 2015) - I-Minerals Inc. (TSX VENTURE: IMA) (OTCQX: IMAHF) ("the Company" or "I-Minerals") is pleased to announce that it has received a report from a leading academic halloysite researcher that covers the results of comparative testing of I-Minerals' HalloPure halloysite with commercially available halloysite from NZ, China and Turkey as well as another development stage US halloysite. Specific testing addressed the potential applications that rely on a stable release of chemical solutions that are important in cosmetic, pharmaceutical, agricultural and paint products. Most of the comparative analysis focused on I-Minerals and the other development stage US halloysite. Overall the analysis concluded that I-Minerals' halloysite has better tubule shapes than commercial NZ and Turkish halloysite. The Chinese halloysite from Hunan Province proved to be a quality product, but it is only available in small amounts (kg). As compared with the other development stage US halloysite, I-Minerals' HalloPure halloysite demonstrated materially longer nanotubes, which may provide better strength in polymeric composites. Loading and release characteristics compare well, showing some potential for better loading efficiency and potential for longer release times.

Scanning Electron Microscope ("SEM") work indicated that I-Minerals halloysite nanotubes ("HNTs") are much longer than any of the other HNTs tested. Most of I-Minerals HNTs measured had a length range of 1.1-2.0μm (75 %). 20 % of the tubes have length of 3.0-5.0μm. The remaining shorter HNTs were considered to be broken pieces off longer tubes. In comparison, the HNTs of the other development stage US producer measured only 0.5 ± 0.2µm, but this halloysite did demonstrate a more uniform HNT size distribution. I-Minerals' much longer HNTs are believed better for stronger polymeric composites. The diameter of I-Minerals HNTs was twice that of the other US halloysite providing improved HNT loading capacity.

A release study was also undertaken wherein I-Minerals' HalloPure HNTs and the other US producer's HNTs were loaded with different solutions and the release time measured. In the first test benzotriazole ("BTA") was loaded into both HNTs simultaneously at the same conditions. A release study in water was also performed simultaneously and the release was measured (260 nm) using a UV-Visible spectrophotometer. Initial burst release in both the cases was close to 70%. However, subsequent release of BTA was slow and sustained with I-Minerals' halloysite. The experiments were repeated at least 3 times to check the consistency of the results, which confirmed the release from I-Minerals' HNTs is longer.