{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:UTVJK3AS7BN4SJJCOWAURYTLLP","short_pith_number":"pith:UTVJK3AS","canonical_record":{"source":{"id":"0905.4451","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-05-27T15:25:36Z","cross_cats_sorted":[],"title_canon_sha256":"313424d12a8bf21f682e01e9942afbe437e7bc78c47d6cf4bf7eb43a758da674","abstract_canon_sha256":"42c7a2d37387db387be1516b79d539991326284d6409292d77aec7a4a12feff4"},"schema_version":"1.0"},"canonical_sha256":"a4ea956c12f85bc92522758148e26b5bf924582b5d6f875b85124f07fd3a9b0f","source":{"kind":"arxiv","id":"0905.4451","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0905.4451","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"arxiv_version","alias_value":"0905.4451v1","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0905.4451","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_12","alias_value":"UTVJK3AS7BN4","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_16","alias_value":"UTVJK3AS7BN4SJJC","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_8","alias_value":"UTVJK3AS","created_at":"2026-07-04T15:42:57Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:UTVJK3AS7BN4SJJCOWAURYTLLP","target":"record","payload":{"canonical_record":{"source":{"id":"0905.4451","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-05-27T15:25:36Z","cross_cats_sorted":[],"title_canon_sha256":"313424d12a8bf21f682e01e9942afbe437e7bc78c47d6cf4bf7eb43a758da674","abstract_canon_sha256":"42c7a2d37387db387be1516b79d539991326284d6409292d77aec7a4a12feff4"},"schema_version":"1.0"},"canonical_sha256":"a4ea956c12f85bc92522758148e26b5bf924582b5d6f875b85124f07fd3a9b0f","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T15:42:57.804149Z","signature_b64":"6hfs7rwEj/5CcSXVvSpi+nMycME128Hfd3F/jEL8ioqwhp/zi4sLXWGlKsJ0K3LXpNVA4uDS9J+KS4Pn7NtrDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a4ea956c12f85bc92522758148e26b5bf924582b5d6f875b85124f07fd3a9b0f","last_reissued_at":"2026-07-04T15:42:57.803738Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T15:42:57.803738Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0905.4451","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T15:42:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6TJK3j2x49c58jzNemXRsR9wo9VZx741wQcMwetMHz9+eg1fbRjVbtKafgpeLd6QlaZcrpGev/QSSSYiskmyCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-19T22:45:58.201383Z"},"content_sha256":"32aac93a4563f61f551c46b9197f1188bb26496b0c9c4f0be0feab206ad1d535","schema_version":"1.0","event_id":"sha256:32aac93a4563f61f551c46b9197f1188bb26496b0c9c4f0be0feab206ad1d535"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:UTVJK3AS7BN4SJJCOWAURYTLLP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Mild sonochemical exfoliation of bromine-intercalated graphite: a new route towards graphene","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"D. W. Boukhvalov, E. Widenkvist, H. Grennberg, J. Lu, K. Leifer, M. I. Katsnelson, R. A. Quinlan, S. Akhtar, S. Rubino, U. Jansson","submitted_at":"2009-05-27T15:25:36Z","abstract_excerpt":"A method to produce suspensions of graphene sheets by combining solution-based bromine intercalation and mild sonochemical exfoliation is presented. Ultrasonic treatment of graphite in water leads to the formation of suspensions of graphite flakes. The delamination is dramatically improved by intercalation of bromine into the graphite before sonication. The bromine intercalation was verified by Raman spectroscopy as well as by x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations show an almost ten times lower interlayer binding energy after introducing Br2 i"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0905.4451","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/0905.4451/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T15:42:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tf4Cw1y4VzAABUiT7QaVsgbxQGdLct9YiWZhwfxvnhtKRMIjTetrf/fa8K2wUVAXXTkeU6+713oBsVE1nbQsBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-19T22:45:58.201744Z"},"content_sha256":"6101772048e10c43ca4826c81ec3dd17eed3de336a4f019300328b434b411b12","schema_version":"1.0","event_id":"sha256:6101772048e10c43ca4826c81ec3dd17eed3de336a4f019300328b434b411b12"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/bundle.json","state_url":"https://pith.science/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-19T22:45:58Z","links":{"resolver":"https://pith.science/pith/UTVJK3AS7BN4SJJCOWAURYTLLP","bundle":"https://pith.science/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/bundle.json","state":"https://pith.science/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/UTVJK3AS7BN4SJJCOWAURYTLLP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:UTVJK3AS7BN4SJJCOWAURYTLLP","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"42c7a2d37387db387be1516b79d539991326284d6409292d77aec7a4a12feff4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-05-27T15:25:36Z","title_canon_sha256":"313424d12a8bf21f682e01e9942afbe437e7bc78c47d6cf4bf7eb43a758da674"},"schema_version":"1.0","source":{"id":"0905.4451","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0905.4451","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"arxiv_version","alias_value":"0905.4451v1","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0905.4451","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_12","alias_value":"UTVJK3AS7BN4","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_16","alias_value":"UTVJK3AS7BN4SJJC","created_at":"2026-07-04T15:42:57Z"},{"alias_kind":"pith_short_8","alias_value":"UTVJK3AS","created_at":"2026-07-04T15:42:57Z"}],"graph_snapshots":[{"event_id":"sha256:6101772048e10c43ca4826c81ec3dd17eed3de336a4f019300328b434b411b12","target":"graph","created_at":"2026-07-04T15:42:57Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/0905.4451/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"A method to produce suspensions of graphene sheets by combining solution-based bromine intercalation and mild sonochemical exfoliation is presented. Ultrasonic treatment of graphite in water leads to the formation of suspensions of graphite flakes. The delamination is dramatically improved by intercalation of bromine into the graphite before sonication. The bromine intercalation was verified by Raman spectroscopy as well as by x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations show an almost ten times lower interlayer binding energy after introducing Br2 i","authors_text":"D. W. Boukhvalov, E. Widenkvist, H. Grennberg, J. Lu, K. Leifer, M. I. Katsnelson, R. A. Quinlan, S. Akhtar, S. Rubino, U. Jansson","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-05-27T15:25:36Z","title":"Mild sonochemical exfoliation of bromine-intercalated graphite: a new route towards graphene"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0905.4451","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:32aac93a4563f61f551c46b9197f1188bb26496b0c9c4f0be0feab206ad1d535","target":"record","created_at":"2026-07-04T15:42:57Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"42c7a2d37387db387be1516b79d539991326284d6409292d77aec7a4a12feff4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-05-27T15:25:36Z","title_canon_sha256":"313424d12a8bf21f682e01e9942afbe437e7bc78c47d6cf4bf7eb43a758da674"},"schema_version":"1.0","source":{"id":"0905.4451","kind":"arxiv","version":1}},"canonical_sha256":"a4ea956c12f85bc92522758148e26b5bf924582b5d6f875b85124f07fd3a9b0f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a4ea956c12f85bc92522758148e26b5bf924582b5d6f875b85124f07fd3a9b0f","first_computed_at":"2026-07-04T15:42:57.803738Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T15:42:57.803738Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"6hfs7rwEj/5CcSXVvSpi+nMycME128Hfd3F/jEL8ioqwhp/zi4sLXWGlKsJ0K3LXpNVA4uDS9J+KS4Pn7NtrDA==","signature_status":"signed_v1","signed_at":"2026-07-04T15:42:57.804149Z","signed_message":"canonical_sha256_bytes"},"source_id":"0905.4451","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:32aac93a4563f61f551c46b9197f1188bb26496b0c9c4f0be0feab206ad1d535","sha256:6101772048e10c43ca4826c81ec3dd17eed3de336a4f019300328b434b411b12"],"state_sha256":"dda8bc934e45b2b9e3fe4b8396d8bb8f011a019eb2867eb5d6bbf975587f7300"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"468Xxg8r+AErDtEpQ/I6F/7a94w7/fBstpuT31jEkArKQXH1HYcXrumOxER65wWt9+CdoTEAAg/tZajKLeGFCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-19T22:45:58.203754Z","bundle_sha256":"98ae667968048569ece41ae5cd23596ecf66185a7f00ff8ed62e1cf23d6f3dcd"}}