1. What are some of the possible barriers to internal collaboration in organizations?

I think the most common barrier to internal collaboration, especially in library setting, is the lack of  technical expertise among the staff members, and also lack of exposure and knowledge of the various web 2.0 social media tools that are available today to communicate effectively within the organization. Most of the staff are not comfortable to use any other means of exchange except telephone and emails, and there is a strong inertia to learn and accept any new technology, as long as it is not absolutely necessary. This trend is particularly common in the older generation (with due respect to them), as I witness at my work everyday. This is probably because most libraries have not reached that height yet where internal communication has to be solely based on technologies and interactive communication.
Another possible barrier to internal communication I think is that everyone involved in entire communication process do not always have the same the level of understanding and experiences on the message that is being transmitted, so that receiver can fully comprehend exact meaning of the information. This can not be possible where there is a difference in the level communication abilities among all the participants, often resulting in failure of internal communication within the organization.
Also, the absence of 'Corporate Culture', as Kelly mentioned in his article is another important reason why internal collaboration fails in some organizations. Every workplace has its own culture, depending on the nature of the services they provide, employee work schedule and the level of interaction required among the employees. In organizations, where employee 'presence beyond office hours' are not expected, everyone works a set schedule everyday without much variation, internal collaboration do not constitute to be an integral part of that work culture, and can not thrive  as  a successful means for organizational communication process.