A　new　route　is　presented　for　the　production　of　carbon　black　(CB)　in　which　the　propane　is　cracked　into　CB　and　hydrogen　using　electric　energy　from　a　low-current,　high-voltage　plasma　discharge.　The　spherical　CB　produced　by　this　process　possessed　a　narrow　size　distribution,　an　average　diameter　of　50　nm　and　a　high　oil　absorption　number　(OAN)　of　136　mL/100　g.　The　prepared　CB　nanoparticles　were　first　hydroxymethylated　with　a　formaldehyde　solution　and　subsequently　oxidized　using　concentrated　nitric　acid　to　introduce　hydroxyl　and　carboxyl　acid　groups　onto　the　CB　surface.　These　hydrophilic　groups　were　beneficial　for　breaking　up　the　large　CB　particles　into　smaller　particles,　and　they　significantly　improved　the　dispersity　of　the　CB　nanoparticles　in　aqueous　media.　The　modified　CB　was　then　coated　by　polyvinylpyrrolidone　(PVP),　in　which　the　carbonyl　oxygens　acted　as　proton　acceptors　to　form　hydrogen　bonds　with　the　carboxyl　acid　groups.　Finally,　the　PVP-coated　CB　was　dispersed　in　an　aqueous　solution　and　was　formulated　into　a　pigmented　ink-jet　ink.　The　physical　and　printing　properties　of　the　prepared　ink　were　demonstrated　to　be　comparable　with　the　commercial　ink.　(C)　2014　Elsevier　B.V.　All　rights　reserved.