In principle you are able to pass all HTML parameters a field can have within the json of the field config.
"type" : "email"
this will make the field being rendered in the editor view like:
<input type="text" type="email">
So you should be able to define something like:
"disabled" : "true"
in order to give this standard HTML attribute to the input.
But keep in mind that just disabling a field won’t reach out to savely prevent users from filling it. One could easy remove the attribute using the browsers-developer console or just send a manual post to the API which contains that field.
In order to protect this field you would need to set up a php snippet in the “write” section of your collection that always clears the content of the disabled field if its set by an user who should not be able to set it…