Ultrahigh-resolution　polymer　materials　with　good　thermal　stability　and　high　interface　contrast　have　a　wide　range　of　application　prospects　in　photolithography　and　nanomanufacturing　processes.　Here,　we　report　a　series　of　comb-like　homopolymers　based　on　polystyrene　sulfonate　imidazolium　salts　(PSSM-(i)imi),　achieving　efficient　self-assembly　under　solvent-free　conditions　and　obtaining　sub-3　nm　hexagonally　packed　cylinders　and　sub-4　nm　lamellar　nanopatterns　with　high　interface　contrast.　The　sulfonic　acid　groups　in　the　main　chain　of　the　homopolymers　are　connected　to　imidazole　groups　containing　hydrophobic　alkyl　side　chains　through　acid-base　mixed　electrostatic　interactions.　The　electrostatic　interactions　enhance　the　incompatibility　between　the　two　functional　groups,　while　the　alkyl　side　chain　can　precisely　control　the　domain　spacing　and　nanostructure　of　the　pattern,　regardless　of　their　molecular　weight.　Through　the　effect　of　temperature　fields,　the　thermal　stability　and　spatial　orientation　of　the　homopolymer　nanostructures　were　further　studied,　promoting　the　practical　application　of　nanopatterned　materials.　©　2025　The　Royal　Society　of　Chemistry.