Introduction Hybrid ion exchangers, i.e. the materials obtained by incorporating organic substances into the inorganic ones are of much interest [1] these days. Introduction of organic species into an inorganic material enhances its reproducibility in ion exchange behaviour and its chemical stability to some extent. Various hybrid ma- terials [2–11] have been prepared in these laborato- ries which have shown promising ion exchange char- acteristics. Surfactants, when present in the matrix of an ion exchanger may enhance its ion exchange ca- pacity and adsorption of metal ions by way of reduc- ing the interfacial tensions between the material (solid) and the aqueous phase (liquid) [12] from which exchange/adsorption takes place. Therefore, these materials are of great importance in industrial and environmental applications. Following pages summarize our such a study on Sn(IV) phosphate cat- ion exchanger, containing a nonionic surfactant, tri- ton X-100 (TX-100) in its matrix. Experimental Tin chloride (SnCl 4 ·5H 2 O) was obtained from CDH (India) while Triton X-100 and phosphoric acid (H 3 PO 4 ) were obtained from Himedia (India) and Qualigens (India) respectively. All other reagents and chemicals were of AnalaR grade. X-ray diffraction studies were performed on a Philips Analytical X-ray B. V. diffractometer type PW 170 B.V. and IR studies were carried out on Shimadzu 8201 PC spectrophotometer while elemen- tal studies were performed using a Heraeus Carlo Erba 1108 elemental analyzer. For TG/DTA/DTG, Perkin Elmer Pyris Diamond model was used. Solutions of tin(IV) chloride, TX-100 and phos- phoric acid were prepared in demineralized water (DMW). TX-100SnP was prepared by adding one volume of 0.3 M tin chloride in two volumes of a (1:1) mix- ture of 0.6 M H 3 PO 4 and 0.0001 M TX-100 solutions, dropwise with constant stirring, provided the highest ion exchange capacity (2.75 meq g –1 ). The resulting slurry was stayed overnight and then filtered and washed with DMW till pH~4. The material was then dried at room temperature and the dried gel was cracked into small granules by putting in DMW and converted into the H + -form by treating with 1 M HNO 3 for 24 h. The material was then washed with DMW to remove excess of acid, dried at room temperature and sieved to 50–70 mesh sized particles. The ion exchange capacity of the sample was de- termined by the column process taking 1 g of the ma- terial (H + -form) in a glass tube of internal diameter 1388–6150/$20.00 Akadémiai Kiadó, Budapest, Hungary © 2007 Akadémiai Kiadó, Budapest Springer, Dordrecht, The Netherlands Journal of Thermal Analysis and Calorimetry, Vol. 90 (2007) 3, 663–667 SYNTHESIS, CHARACTERIZATION AND ADSORPTION BEHAVIOUR OF TX-100 BASED Sn(IV) PHOSPHATE, A NEW HYBRID ION EXCHANGER Separation of Ni(II) from Hg(II), Pb(II) and Fe(III) on its column K. G. Varshney 1 , M. Z. A. Rafiquee 2 and Amita Somya 2* 1 Manav Rachna College of Engineering, Sector 43, Aravalli Hills, Delhi-Surajkund Road, Faridabad 121004, India 2 Department of Applied Chemistry, Z. H.College of Engineering and Technology, Aligarh Muslim University, Aligarh 202002, India A new hybrid ion exchanger, Triton X-100 based tin(IV) phosphate (TX-100SnP) has been synthesized and characterized by ion ex- change and physico-chemical methods such as ion exchange capacity, elution and concentration behaviour, IR, X-ray, TG/DTA and elemental analysis. Its adsorption behaviour has also been studied for some alkaline earths and heavy metal ions in different acidic media. It has been found generally more selective for metal ions as compared to tin(IV) phosphate prepared earlier. For Pb(II), Hg(II) and Fe(III) its selectivity has been found to be exceptionally good. On this basis, some binary separations have been per- formed involving these metal ions. Thermal studies show a high thermal stability of the material. It retains 54.54% of its i.e.c. at 200°C and 27.27% at 300°C. Keywords: characterization, Fe(III), Hg(II), Ni(II), Pb(II), Sn(IV), synthesis, TX-100 * Author for correspondence: amita_somya@rediffmail.com