{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"bb4953e0ccaf50c0c792434a05ac396de957c978d7749d52aa7c61bd28c243b0","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["200efd7b0fa7fa7955671d2ab4f286bd0a3b82b01fad0ab367c519bd75100b9f","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"702414457c1cf53a975cec235abe1252d82f6b3f0cdfcf047a037f78a9f955f4","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"chem.aqueous-interfaces.hofmeister-mechanism","kind":"phenomenon","literature_status":"contested","n":"2","parents":[],"plain":"Since 1888 it has been known that salts fall in a fixed order, the Hofmeister series, in how strongly they make proteins precipitate. Why ions of the same charge rank this way is still debated.","posed_since":"1888","precise":"Explain the anion ordering of the Hofmeister series (roughly SO4^2- > F- > Cl- > Br- > $\\mathrm{NO_3}$- > I- > $\\mathrm{ClO_4}$- > SCN-) in protein salting-out, nonpolar solute solubility and electrolyte surface tension, choosing among bulk water structure making and breaking, direct ion-solute pairing, interfacial adsorption driven by polarizability and partial dehydration, and ion-specific dispersion forces. An answer is a quantitative model with parameters from first principles or independent data that reproduces the ordering and its reversal on positively charged or hydrophobic surfaces.","problem_ref":"200efd7b0fa7fa7955671d2ab4f286bd0a3b82b01fad0ab367c519bd75100b9f","references":"","settled_by":"Ion-resolved measurements at protein and model interfaces compared with simulations using polarizable or ab initio potentials across the whole series.","status_note":"Explanations based on bulk water structure lost support in the 2000s in favor of direct ion-interface interactions, but no single quantitative model covers the series (Jungwirth and Cremer, Nature Chemistry 2014, https://doi.org/10.1038/nchem.1899).","title":"Molecular mechanism of the Hofmeister series","topic_ref":null},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8d70341e1a2eed359847e2bb8893f8165a9ad0c84d15d5cee2b3aaea4c196db6","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"254bb218bdc934228e16af42baef42ba4ed0f009799ef866e9a7365065f5ce68","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"rPvwsULGsh-U-g8IW9aZjkb6eUQMMfAsfTVp9XqPi67sVAvUc7L-lCr38pF8LepCZ-L0QbGVflSC1z0hVuQCAw"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIJUuyGL3JNCKOFq9Cuu9Cuk7Q8Al5nvhm6ac2UGX1zmjwICVLyTrOwCbD10GrTGN-egt7RYb2fYqSyJtXhMfaPBelCPEgNt6ufQkr3QceaTHR0C4ZXfDwcNORwX8EKKuALIk7eN0I8CAUdoEzkIfEaubziQ-BfepfgoGnVms835H1pHwWkGYgfwjxIIQkdNl7luc6V22MrbArX9nP1jcCRzqBgMj6S8Dq_FpQCPEg6PHrG6S105MweA0hEv6Na71I7Ne3XrckX3TiTHL-80oI8SClehk4kg242izhJrq_E_tagve9Vmc9VZxesxsdo1-l-gjxIACQj7hTnt3eJLkSmDJTNTyOSwO3o1e3cI0C3xqbxiWlCPEgbfsqNEiKd31vqHmWLbVpOwfRJ_Z2YUckwYh0fQRhz9sI8SCHI26f1bMr-H5VtXG_HgMHDd8PPImPLhsWPB8PPaY3jwjwIKD8mGRUgbk2Dt1xG-4OxMpCuw1ya5UEUQXsqASURGCtCPAgkPXX-naXR0fRIdS-sEDlzYmtMvSCNH42ESUF0QXb6NUI8CDQo_sIWZiWXaTGRSQBLmU-lHJKskYKqsjO1r02DhB8LAj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIFJv9vakjLUQTQvo-5xoO7r-uaeT-DGXPRjxkfqFfHmPwIBTMvmgzqKUWOqrO4jnFHqoxZsZzk4I8QBKK7z8dNbEJCPEgWdoNKAyu8qvTUM2Xq0hBttjfPzzmuXcTvHDbUnNi25MI8CCCYn0sCTj8BMCwiTaiZurA2vmSt9YCRBWXJmnKDq22ewjwIDbAT1xssu271pdD7lnrc657pIDgyPyl6wJs4JzxJdpaCPEgNxkS_K6lO6HEIjzc_Ux1Hh3O5FY6TEcTWobfNpX6QbII8CBUtT-rAlcbWqltwNkxh-vzYVLpubCMIg3-1ux8V_0IJQjwIBOvfBQRBP4iTAnLt1neEKzJY5cH42A1iH1qQbJbWNT7CPAgQEjWwWlWWX3vJoLxfq0lixNb2cwGMRGhB0ekxjFJDZAI8SCHI26f1bMr-H5VtXG_HgMHDd8PPImPLhsWPB8PPaY3jwjwIKD8mGRUgbk2Dt1xG-4OxMpCuw1ya5UEUQXsqASURGCtCPAgkPXX-naXR0fRIdS-sEDlzYmtMvSCNH42ESUF0QXb6NUI8CDQo_sIWZiWXaTGRSQBLmU-lHJKskYKqsjO1r02DhB8LAj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"]},"log":{"leaf_index":"2640","tree_size":"3804","proof":["f09e31a9034156fab9e9cd7c651266da80afb0fd03cc3c2b595f78b5d963d502","2547ea458026dff7d73485ff99448a3c3dffcef90c6b0b4ac8220441fe51b059","57f65d0a878664ddfcb4a13b2434c9f69b880996ccf394b98a63b06673ec5733","85e7b8429b304c298b3882954088a04bf20a1f0956abc16278267d76a9fc55a1","4a50397440db02607db07a24f6712eebbfb7caf4f4325c3644b88dc6e929a05b","9c9cad048acf8bc9bbf43405278a93b0ec434a435e0522ff1ad40598b047540a","c47f95d5f505dd3f4a0ccd3ee165d6a8a2c83eb029435245432a06aec652c51d","417e92ef51c0a0008c132796395eb6d1d4b2168a145810e24d5d0ce3b743645d","c5dbfd47d4733f672f10a08c156fed0942802569cf36e89d6af3957344f7d18d","b0b232078d071c92816af6274529aef23a2ea1f41246694fec32d768cfa09dc8","325287f5a43e4f3ad4072ec4bd53d43c50c1393021a056122e9cb0fad83b868f","3c578dccc15502c5f3efe228cadc99fee76ab536ed01f66b14d316fdcc157429"],"checkpoint":"pubphys.com/log/v1\n3804\nAK6t4qgu96+M9wScTrIlsJ10d/zhKVEtYguyM3aeJvo=\n\n— pubphys.com/log/v1 JFPwIPP8EtoxgcsQg7V7CwIdL4UKPqJtpv+eB8sFNJjyQHIdyA1VabmBsPyLqq2bLxJPn57rA6fQi8y0QDDjRXHvlQg=\n","promise":"pubphys.com/log/v1 promise\n2b5340c34a06aedd0b27b8804ca577e2c088a5eea27431aec2d00aaa8bd24e16\n2640\n2026-10-15T23:43:57Z\n2026-10-16T01:43:57Z\n\n— pubphys.com/log/v1 JFPwIKVZbMucqWBQ8ajIsjo1XJUsPQiKfJ9+tMDDB+BRR03o1xOIubL4IrwA2nlSGvHjP0I6gDNUbVyNQwm7RkfqzwE=\n"},"orcid_key_evidence":[],"attesting":null}