A　series　of　double-chain　sulfobetain　zwitterionic　surfactants　with　varying　carbon　number　of　the　intercharge　group　(spacer),　(C16H33)(2)NCH3(CH2)(n)SO3,　where　n=2,　3,　4　and　6,　referred　to　as　(C-16)(2)NCnS,　were　synthesized.　The　influence　of　the　spacer　length　on　the　thermal　behaviors　of　(C-16)(2)NCnS　in　their　pure　state　was　studied　using　thermogravimetry　(TG),　differential　scanning　calorimetry　(DSC),　polarizing　optical　microscopy　(POM),　and　X-ray　diffraction　(XRD).　Thermogravimetric　analysis　(TGA)　showed　that　the　thermal　stability　of　(C-16)(2)NCnS　lowered　with　increasing　the　spacer　length.　All　compounds　showed　a　complex　polymorphism.　Only　for　(C-16)(2)NC4S　and　(C-16)(2)NC6S　thermotropic　liquid　crystals　were　observed　using　POM.　The　former　exhibited　a　striectic　A　(SmA)　phase,　whereas　the　latter　formed　a　hexagonal　columnar　phase.　These　liquid　crystals　obtained　both　in　the　cooling　and　the　second　heating　scans　provided　compelling　evidence　for　the　thermal　stability　of　these　compounds.